Merge branch 'rebis-dev' of https://github.com/mthom/scryer-prolog into rebis-dev

Cargo.lock

@@ -878,7 +878,7 @@ dependencies = [
 ]
 
 [[package]]
-name = "prolog_parser_rebis"
+name = "prolog_parser"
 version = "0.8.68"
 dependencies = [
  "lexical",
@@ -1221,7 +1221,7 @@ dependencies = [
  "num-rug-adapter",
  "openssl",
  "ordered-float",
- "prolog_parser_rebis",
+ "prolog_parser",
  "ref_thread_local",
  "ring",
  "ripemd160",

Cargo.toml

@@ -18,8 +18,8 @@ members = ["crates/prolog_parser"]
 indexmap = "1.0.2"
 
 [features]
-default = ["rug", "prolog_parser_rebis/rug"]
+default = ["rug", "prolog_parser/rug"]
-num = ["num-rug-adapter", "prolog_parser_rebis/num"]
+num = ["num-rug-adapter", "prolog_parser/num"]
 
 [dependencies]
 cpu-time = "1.0.0"
@@ -35,7 +35,7 @@ libc = "0.2.62"
 nix = "0.15.0"
 num-rug-adapter = { optional = true, version = "0.1.4" }
 ordered-float = "0.5.0"
-prolog_parser_rebis = { path = "./crates/prolog_parser", default-features = false }
+prolog_parser = { path = "./crates/prolog_parser", default-features = false }
 ref_thread_local = "0.0.0"
 rug = { version = "1.4.0", optional = true }
 rustyline = "7.0.0"

build.rs

@@ -1,5 +1,3 @@
-extern crate indexmap;
-
 use std::env;
 use std::fs;
 use std::fs::File;
@@ -15,15 +13,13 @@ fn find_prolog_files(libraries: &mut File, prefix: &str, current_dir: &Path) {
     for entry in entries.filter_map(Result::ok).map(|e| e.path()) {
         if entry.is_dir() {
             if let Some(file_name) = entry.file_name() {
-                let new_prefix =
+                let new_prefix = prefix.to_owned() + file_name.to_str().unwrap() + "/";
-                    prefix.to_owned() + file_name.to_str().unwrap() + "/";
                 find_prolog_files(libraries, &new_prefix, &entry);
             }
         } else if entry.is_file() {
             let ext = std::ffi::OsStr::new("pl");
             if entry.extension() == Some(ext) {
-                let contain =
+                let contain = String::from_utf8(fs::read(&entry).unwrap()).unwrap();
-                    String::from_utf8(fs::read(&entry).unwrap()).unwrap();
                 let name = entry.file_stem().unwrap().to_str().unwrap();
 
                 let line = format!(
@@ -47,7 +43,7 @@ fn main() {
 
     libraries
         .write_all(
-            b"ref_thread_local! {
+            b"ref_thread_local::ref_thread_local! {
     pub static managed LIBRARIES: IndexMap<&'static str, &'static str> = {
         let mut m = IndexMap::new();\n",
         )

crates/prolog_parser/Cargo.lock

@@ -148,7 +148,7 @@ dependencies = [
 ]
 
 [[package]]
-name = "prolog_parser_rebis"
+name = "prolog_parser"
 version = "0.8.68"
 dependencies = [
  "lexical",

crates/prolog_parser/Cargo.toml

@@ -1,8 +1,9 @@
 [package]
-name = "prolog_parser_rebis"
+name = "prolog_parser"
 version = "0.8.68"
 authors = ["Mark Thom <markjordanthom@gmail.com>"]
-repository = "https://github.com/mthom/prolog_parser"
+edition = "2018"
+repository = "https://github.com/mthom/scryer-prolog"
 description = " An operator precedence parser for the Rebis development version of Scryer Prolog, an up and coming ISO Prolog implementation."
 license = "BSD-3-Clause"
 

crates/prolog_parser/src/ast.rs

@@ -1,8 +1,8 @@
-use rug::{Integer, Rational};
+use crate::rug::{Integer, Rational};
+use crate::tabled_rc::*;
 use ordered_float::*;
-use tabled_rc::*;
 
-use put_back_n::*;
+use crate::put_back_n::*;
 
 use std::cell::Cell;
 use std::cmp::Ordering;
@@ -27,112 +27,150 @@ pub const MAX_ARITY: usize = 1023;
 pub const XFX: u32 = 0x0001;
 pub const XFY: u32 = 0x0002;
 pub const YFX: u32 = 0x0004;
-pub const XF: u32  = 0x0010;
+pub const XF: u32 = 0x0010;
-pub const YF: u32  = 0x0020;
+pub const YF: u32 = 0x0020;
-pub const FX: u32  = 0x0040;
+pub const FX: u32 = 0x0040;
-pub const FY: u32  = 0x0080;
+pub const FY: u32 = 0x0080;
 pub const DELIMITER: u32 = 0x0100;
-pub const TERM: u32  = 0x1000;
+pub const TERM: u32 = 0x1000;
 pub const LTERM: u32 = 0x3000;
 
 pub const NEGATIVE_SIGN: u32 = 0x0200;
 
 #[macro_export]
 macro_rules! clause_name {
-    ($name: expr, $tbl: expr) => (
+    ($name: expr, $tbl: expr) => {
-        ClauseName::User(TabledRc::new($name, $tbl.clone()))
+        $crate::ast::ClauseName::User($crate::tabled_rc::TabledRc::new($name, $tbl.clone()))
-    ) ;
+    };
-    ($name: expr) => (
+    ($name: expr) => {
-        ClauseName::BuiltIn($name)
+        $crate::ast::ClauseName::BuiltIn($name)
-    )
+    };
 }
 
 #[macro_export]
 macro_rules! atom {
-    ($e:expr, $tbl:expr) => (
+    ($e:expr, $tbl:expr) => {
-        Constant::Atom(ClauseName::User(tabled_rc!($e, $tbl)), None)
+        $crate::ast::Constant::Atom(
-    );
+            $crate::ast::ClauseName::User($crate::tabled_rc!($e, $tbl)),
-    ($e:expr) => (
+            None,
-        Constant::Atom(clause_name!($e), None)
+        )
-    )
+    };
+    ($e:expr) => {
+        $crate::ast::Constant::Atom($crate::clause_name!($e), None)
+    };
 }
 
 #[macro_export]
 macro_rules! rc_atom {
-    ($e:expr) => (
+    ($e:expr) => {
         Rc::new(String::from($e))
-    )
+    };
 }
 macro_rules! is_term {
-    ($x:expr) => ( ($x & TERM) != 0 )
+    ($x:expr) => {
+        ($x & $crate::ast::TERM) != 0
+    };
 }
 
 macro_rules! is_lterm {
-    ($x:expr) => ( ($x & LTERM) != 0 )
+    ($x:expr) => {
+        ($x & $crate::ast::LTERM) != 0
+    };
 }
 
 macro_rules! is_op {
-    ($x:expr) => ( $x & (XF | YF | FX | FY | XFX | XFY | YFX) != 0 )
+    ($x:expr) => {
+        $x & ($crate::ast::XF
+            | $crate::ast::YF
+            | $crate::ast::FX
+            | $crate::ast::FY
+            | $crate::ast::XFX
+            | $crate::ast::XFY
+            | $crate::ast::YFX)
+            != 0
+    };
 }
 
 macro_rules! is_negate {
-    ($x:expr) => ( ($x & NEGATIVE_SIGN) != 0 )
+    ($x:expr) => {
+        ($x & $crate::ast::NEGATIVE_SIGN) != 0
+    };
 }
 
 #[macro_export]
 macro_rules! is_prefix {
-    ($x:expr) => ( $x & (FX | FY) != 0 )
+    ($x:expr) => {
+        $x & ($crate::ast::FX | $crate::ast::FY) != 0
+    };
 }
 
 #[macro_export]
 macro_rules! is_postfix {
-    ($x:expr) => ( $x & (XF | YF) != 0 )
+    ($x:expr) => {
+        $x & ($crate::ast::XF | $crate::ast::YF) != 0
+    };
 }
 
 #[macro_export]
 macro_rules! is_infix {
-    ($x:expr) => ( ($x & (XFX | XFY | YFX)) != 0 )
+    ($x:expr) => {
+        ($x & ($crate::ast::XFX | $crate::ast::XFY | $crate::ast::YFX)) != 0
+    };
 }
 
 #[macro_export]
 macro_rules! is_xfx {
-    ($x:expr) => ( ($x & XFX) != 0 )
+    ($x:expr) => {
+        ($x & $crate::ast::XFX) != 0
+    };
 }
 
 #[macro_export]
 macro_rules! is_xfy {
-    ($x:expr) => ( ($x & XFY) != 0 )
+    ($x:expr) => {
+        ($x & $crate::ast::XFY) != 0
+    };
 }
 
 #[macro_export]
 macro_rules! is_yfx {
-    ($x:expr) => ( ($x & YFX) != 0 )
+    ($x:expr) => {
+        ($x & $crate::ast::YFX) != 0
+    };
 }
 
 #[macro_export]
 macro_rules! is_yf {
-    ($x:expr) => ( ($x & YF) != 0 )
+    ($x:expr) => {
+        ($x & $crate::ast::YF) != 0
+    };
 }
 
 #[macro_export]
 macro_rules! is_xf {
-    ($x:expr) => ( ($x & XF) != 0 )
+    ($x:expr) => {
+        ($x & $crate::ast::XF) != 0
+    };
 }
 
 #[macro_export]
 macro_rules! is_fx {
-    ($x:expr) => ( ($x & FX) != 0 )
+    ($x:expr) => {
+        ($x & $crate::ast::FX) != 0
+    };
 }
 
 #[macro_export]
 macro_rules! is_fy {
-    ($x:expr) => ( ($x & FY) != 0 )
+    ($x:expr) => {
+        ($x & $crate::ast::FY) != 0
+    };
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub enum RegType {
     Perm(usize),
-    Temp(usize)
+    Temp(usize),
 }
 
 impl Default for RegType {
@@ -144,23 +182,20 @@ impl Default for RegType {
 impl RegType {
     pub fn reg_num(self) -> usize {
         match self {
-            RegType::Perm(reg_num) | RegType::Temp(reg_num) => reg_num
+            RegType::Perm(reg_num) | RegType::Temp(reg_num) => reg_num,
         }
     }
 
     pub fn is_perm(self) -> bool {
-        match self {
+        matches!(self, RegType::Perm(_))
-            RegType::Perm(_) => true,
-            _ => false
-        }
     }
 }
 
 impl fmt::Display for RegType {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
-            &RegType::Perm(val) => write!(f, "Y{}", val),
+            RegType::Perm(val) => write!(f, "Y{}", val),
-            &RegType::Temp(val) => write!(f, "X{}", val)
+            RegType::Temp(val) => write!(f, "X{}", val),
         }
     }
 }
@@ -168,13 +203,13 @@ impl fmt::Display for RegType {
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub enum VarReg {
     ArgAndNorm(RegType, usize),
-    Norm(RegType)
+    Norm(RegType),
 }
 
 impl VarReg {
     pub fn norm(self) -> RegType {
         match self {
-            VarReg::ArgAndNorm(reg, _) | VarReg::Norm(reg) => reg
+            VarReg::ArgAndNorm(reg, _) | VarReg::Norm(reg) => reg,
         }
     }
 }
@@ -182,12 +217,10 @@ impl VarReg {
 impl fmt::Display for VarReg {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
-            &VarReg::Norm(RegType::Perm(reg)) => write!(f, "Y{}", reg),
+            VarReg::Norm(RegType::Perm(reg)) => write!(f, "Y{}", reg),
-            &VarReg::Norm(RegType::Temp(reg)) => write!(f, "X{}", reg),
+            VarReg::Norm(RegType::Temp(reg)) => write!(f, "X{}", reg),
-            &VarReg::ArgAndNorm(RegType::Perm(reg), arg) =>
+            VarReg::ArgAndNorm(RegType::Perm(reg), arg) => write!(f, "Y{} A{}", reg, arg),
-                write!(f, "Y{} A{}", reg, arg),
+            VarReg::ArgAndNorm(RegType::Temp(reg), arg) => write!(f, "X{} A{}", reg, arg),
-            &VarReg::ArgAndNorm(RegType::Temp(reg), arg) =>
-                write!(f, "X{} A{}", reg, arg)
         }
     }
 }
@@ -200,28 +233,30 @@ impl Default for VarReg {
 
 #[macro_export]
 macro_rules! temp_v {
-    ($x:expr) => (
+    ($x:expr) => {
-        RegType::Temp($x)
+        $crate::ast::RegType::Temp($x)
-    )
+    };
 }
 
 #[macro_export]
 macro_rules! perm_v {
-    ($x:expr) => (
+    ($x:expr) => {
-        RegType::Perm($x)
+        $crate::ast::RegType::Perm($x)
-    )
+    };
 }
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
 pub enum GenContext {
-    Head, Mid(usize), Last(usize) // Mid & Last: chunk_num
+    Head,
+    Mid(usize),
+    Last(usize), // Mid & Last: chunk_num
 }
 
 impl GenContext {
     pub fn chunk_num(self) -> usize {
         match self {
             GenContext::Head => 0,
-            GenContext::Mid(cn) | GenContext::Last(cn) => cn
+            GenContext::Mid(cn) | GenContext::Last(cn) => cn,
         }
     }
 }
@@ -247,43 +282,35 @@ pub type OpDir = HashMap<OpDirKey, OpDirValue>;
 
 #[derive(Debug, Clone, Copy)]
 pub struct MachineFlags {
-    pub double_quotes: DoubleQuotes
+    pub double_quotes: DoubleQuotes,
 }
 
 impl Default for MachineFlags {
     fn default() -> Self {
-        MachineFlags { double_quotes: DoubleQuotes::default() }
+        MachineFlags {
+            double_quotes: DoubleQuotes::default(),
+        }
     }
 }
 
 #[derive(Debug, Clone, Copy)]
 pub enum DoubleQuotes {
-    Atom, Chars, Codes
+    Atom,
+    Chars,
+    Codes,
 }
 
 impl DoubleQuotes {
     pub fn is_chars(self) -> bool {
-        if let DoubleQuotes::Chars = self {
+        matches!(self, DoubleQuotes::Chars)
-            true
-        } else {
-            false
-        }
     }
 
     pub fn is_atom(self) -> bool {
-        if let DoubleQuotes::Atom = self {
+        matches!(self, DoubleQuotes::Atom)
-            true
-        } else {
-            false
-        }
     }
 
     pub fn is_codes(self) -> bool {
-        if let DoubleQuotes::Codes = self {
+        matches!(self, DoubleQuotes::Codes)
-            true
-        } else {
-            false
-        }
     }
 }
 
@@ -296,10 +323,10 @@ impl Default for DoubleQuotes {
 pub fn default_op_dir() -> OpDir {
     let mut op_dir = OpDir::new();
 
-    op_dir.insert((clause_name!(":-"), Fixity::In),  OpDirValue::new(XFX, 1200));
+    op_dir.insert((clause_name!(":-"), Fixity::In), OpDirValue::new(XFX, 1200));
-    op_dir.insert((clause_name!(":-"), Fixity::Pre), OpDirValue::new(FX,  1200));
+    op_dir.insert((clause_name!(":-"), Fixity::Pre), OpDirValue::new(FX, 1200));
-    op_dir.insert((clause_name!("?-"), Fixity::Pre), OpDirValue::new(FX,  1200));
+    op_dir.insert((clause_name!("?-"), Fixity::Pre), OpDirValue::new(FX, 1200));
-    op_dir.insert((clause_name!(","), Fixity::In),   OpDirValue::new(XFY, 1000));
+    op_dir.insert((clause_name!(","), Fixity::In), OpDirValue::new(XFY, 1000));
 
     op_dir
 }
@@ -307,7 +334,7 @@ pub fn default_op_dir() -> OpDir {
 #[derive(Debug, Clone)]
 pub enum ArithmeticError {
     NonEvaluableFunctor(Constant, usize),
-    UninstantiatedVar
+    UninstantiatedVar,
 }
 
 #[derive(Debug)]
@@ -321,47 +348,35 @@ pub enum ParserError {
     MissingQuote(usize, usize),
     NonPrologChar(usize, usize),
     ParseBigInt(usize, usize),
-    Utf8Error(usize, usize)
+    Utf8Error(usize, usize),
 }
 
 impl ParserError {
     pub fn line_and_col_num(&self) -> Option<(usize, usize)> {
         match self {
             &ParserError::BackQuotedString(line_num, col_num)
-          | &ParserError::UnexpectedChar(_, line_num, col_num)
+            | &ParserError::UnexpectedChar(_, line_num, col_num)
-          | &ParserError::IncompleteReduction(line_num, col_num)
+            | &ParserError::IncompleteReduction(line_num, col_num)
-          | &ParserError::MissingQuote(line_num, col_num)
+            | &ParserError::MissingQuote(line_num, col_num)
-          | &ParserError::NonPrologChar(line_num, col_num)
+            | &ParserError::NonPrologChar(line_num, col_num)
-          | &ParserError::ParseBigInt(line_num, col_num)
+            | &ParserError::ParseBigInt(line_num, col_num)
-          | &ParserError::Utf8Error(line_num, col_num) =>
+            | &ParserError::Utf8Error(line_num, col_num) => Some((line_num, col_num)),
-                Some((line_num, col_num)),
+            _ => None,
-            _ =>
-                None
         }
     }
 
     pub fn as_str(&self) -> &'static str {
         match self {
-            &ParserError::BackQuotedString(..) =>
+            ParserError::BackQuotedString(..) => "back_quoted_string",
-                "back_quoted_string",
+            ParserError::UnexpectedChar(..) => "unexpected_char",
-            &ParserError::UnexpectedChar(..) =>
+            ParserError::UnexpectedEOF => "unexpected_end_of_file",
-                "unexpected_char",
+            ParserError::IncompleteReduction(..) => "incomplete_reduction",
-            &ParserError::UnexpectedEOF =>
+            ParserError::InvalidSingleQuotedCharacter(..) => "invalid_single_quoted_character",
-                "unexpected_end_of_file",
+            ParserError::IO(_) => "input_output_error",
-            &ParserError::IncompleteReduction(..) =>
+            ParserError::MissingQuote(..) => "missing_quote",
-                "incomplete_reduction",
+            ParserError::NonPrologChar(..) => "non_prolog_character",
-            &ParserError::InvalidSingleQuotedCharacter(..) =>
+            ParserError::ParseBigInt(..) => "cannot_parse_big_int",
-                "invalid_single_quoted_character",
+            ParserError::Utf8Error(..) => "utf8_conversion_error",
-            &ParserError::IO(_) =>
-                "input_output_error",
-            &ParserError::MissingQuote(..) =>
-                "missing_quote",
-            &ParserError::NonPrologChar(..) =>
-                "non_prolog_character",
-            &ParserError::ParseBigInt(..) =>
-                "cannot_parse_big_int",
-            &ParserError::Utf8Error(..) =>
-                "utf8_conversion_error",
         }
     }
 }
@@ -382,39 +397,38 @@ impl From<&IOError> for ParserError {
     }
 }
 
-
 #[derive(Debug, Clone, Copy)]
 pub struct CompositeOpDir<'a, 'b> {
     pub primary_op_dir: Option<&'b OpDir>,
     pub secondary_op_dir: &'a OpDir,
 }
 
-impl<'a, 'b> CompositeOpDir<'a, 'b>
+impl<'a, 'b> CompositeOpDir<'a, 'b> {
-{
     #[inline]
     pub fn new(secondary_op_dir: &'a OpDir, primary_op_dir: Option<&'b OpDir>) -> Self {
-        CompositeOpDir { primary_op_dir, secondary_op_dir }
+        CompositeOpDir {
+            primary_op_dir,
+            secondary_op_dir,
+        }
     }
 
     #[inline]
-    pub(crate)
+    pub(crate) fn get(&self, name: ClauseName, fixity: Fixity) -> Option<&OpDirValue> {
-    fn get(&self, name: ClauseName, fixity: Fixity) -> Option<&OpDirValue>
+        let entry = if let Some(ref primary_op_dir) = &self.primary_op_dir {
-    {
+            primary_op_dir.get(&(name.clone(), fixity))
-        let entry =
+        } else {
-            if let Some(ref primary_op_dir) = &self.primary_op_dir {
+            None
-                primary_op_dir.get(&(name.clone(), fixity))
+        };
-            } else {
-                None
-            };
 
         entry.or_else(move || self.secondary_op_dir.get(&(name, fixity)))
     }
 }
 
-
 #[derive(Debug, Clone, Copy, Eq, Hash, PartialEq, PartialOrd, Ord)]
 pub enum Fixity {
-    In, Post, Pre
+    In,
+    Post,
+    Pre,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
@@ -496,28 +510,21 @@ pub enum Constant {
 impl fmt::Display for Constant {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
-            &Constant::Atom(ref atom, _) =>
+            Constant::Atom(ref atom, _) => {
                 if atom.as_str().chars().any(|c| "`.$'\" ".contains(c)) {
                     write!(f, "'{}'", atom.as_str())
                 } else {
                     write!(f, "{}", atom.as_str())
-                },
+                }
-            &Constant::Char(c) =>
+            }
-                write!(f, "'{}'", c as u32),
+            Constant::Char(c) => write!(f, "'{}'", *c as u32),
-            &Constant::EmptyList =>
+            Constant::EmptyList => write!(f, "[]"),
-                write!(f, "[]"),
+            Constant::Fixnum(n) => write!(f, "{}", n),
-            &Constant::Fixnum(n) =>
+            Constant::Integer(ref n) => write!(f, "{}", n),
-                write!(f, "{}", n),
+            Constant::Rational(ref n) => write!(f, "{}", n),
-            &Constant::Integer(ref n) =>
+            Constant::Float(ref n) => write!(f, "{}", n),
-                write!(f, "{}", n),
+            Constant::String(ref s) => write!(f, "\"{}\"", &s),
-            &Constant::Rational(ref n) =>
+            Constant::Usize(integer) => write!(f, "u{}", integer),
-                write!(f, "{}", n),
-            &Constant::Float(ref n) =>
-                write!(f, "{}", n),
-            &Constant::String(ref s) =>
-                write!(f, "\"{}\"", &s),
-            &Constant::Usize(integer) =>
-                write!(f, "u{}", integer),
         }
     }
 }
@@ -526,37 +533,27 @@ impl PartialEq for Constant {
     fn eq(&self, other: &Constant) -> bool {
         match (self, other) {
             (&Constant::Atom(ref atom, _), &Constant::Char(c))
-          | (&Constant::Char(c), &Constant::Atom(ref atom, _)) => {
+            | (&Constant::Char(c), &Constant::Atom(ref atom, _)) => {
-              atom.is_char() && Some(c) == atom.as_str().chars().next()
+                atom.is_char() && atom.as_str().starts_with(c)
-            },
+            }
-            (&Constant::Atom(ref a1, _), &Constant::Atom(ref a2, _)) =>
+            (&Constant::Atom(ref a1, _), &Constant::Atom(ref a2, _)) => a1.as_str() == a2.as_str(),
-                a1.as_str() == a2.as_str(),
+            (&Constant::Char(c1), &Constant::Char(c2)) => c1 == c2,
-            (&Constant::Char(c1), &Constant::Char(c2)) =>
+            (&Constant::Fixnum(n1), &Constant::Fixnum(n2)) => n1 == n2,
-                c1 == c2,
+            (&Constant::Fixnum(n1), &Constant::Integer(ref n2))
-            (&Constant::Fixnum(n1), &Constant::Fixnum(n2)) =>
+            | (&Constant::Integer(ref n2), &Constant::Fixnum(n1)) => {
-                n1 == n2,
-            (&Constant::Fixnum(n1), &Constant::Integer(ref n2)) |
-            (&Constant::Integer(ref n2), &Constant::Fixnum(n1)) => {
                 if let Some(n2) = n2.to_isize() {
                     n1 == n2
                 } else {
                     false
                 }
             }
-            (&Constant::Integer(ref n1), &Constant::Integer(ref n2)) =>
+            (&Constant::Integer(ref n1), &Constant::Integer(ref n2)) => n1 == n2,
-                n1 == n2,
+            (&Constant::Rational(ref n1), &Constant::Rational(ref n2)) => n1 == n2,
-            (&Constant::Rational(ref n1), &Constant::Rational(ref n2)) =>
+            (&Constant::Float(ref n1), &Constant::Float(ref n2)) => n1 == n2,
-                n1 == n2,
+            (&Constant::String(ref s1), &Constant::String(ref s2)) => s1 == s2,
-            (&Constant::Float(ref n1), &Constant::Float(ref n2)) =>
+            (&Constant::EmptyList, &Constant::EmptyList) => true,
-                n1 == n2,
+            (&Constant::Usize(u1), &Constant::Usize(u2)) => u1 == u2,
-            (&Constant::String(ref s1), &Constant::String(ref s2)) => {
+            _ => false,
-                &s1 == &s2
-            }
-            (&Constant::EmptyList, &Constant::EmptyList) =>
-                true,
-            (&Constant::Usize(u1), &Constant::Usize(u2)) =>
-                u1 == u2,
-            _ => false
         }
     }
 }
@@ -564,10 +561,10 @@ impl PartialEq for Constant {
 impl Eq for Constant {}
 
 impl Constant {
-    pub fn to_atom(self) -> Option<ClauseName> {
+    pub fn to_atom(&self) -> Option<ClauseName> {
         match self {
             Constant::Atom(a, _) => Some(a.defrock_brackets()),
-            _ => None
+            _ => None,
         }
     }
 }
@@ -575,7 +572,7 @@ impl Constant {
 #[derive(Debug, Clone)]
 pub enum ClauseName {
     BuiltIn(&'static str),
-    User(TabledRc<Atom>)
+    User(TabledRc<Atom>),
 }
 
 impl fmt::Display for ClauseName {
@@ -620,20 +617,22 @@ impl ClauseName {
     #[inline]
     pub fn owning_module(&self) -> Self {
         match self {
-            &ClauseName::User(ref name) => {
+            ClauseName::User(ref name) => {
                 let module = name.owning_module();
-                ClauseName::User(TabledRc { atom: module.clone(),
+                ClauseName::User(TabledRc {
-                                            table: TabledData::new(module) })
+                    atom: module.clone(),
-            },
+                    table: TabledData::new(module),
-            _ => clause_name!("user")
+                })
+            }
+            _ => clause_name!("user"),
         }
     }
 
     #[inline]
     pub fn to_rc(&self) -> Rc<String> {
         match self {
-            &ClauseName::BuiltIn(s) => Rc::new(s.to_string()),
+            ClauseName::BuiltIn(s) => Rc::new(s.to_string()),
-            &ClauseName::User(ref rc) => rc.inner()
+            ClauseName::User(ref rc) => rc.inner(),
         }
     }
 
@@ -660,52 +659,46 @@ impl ClauseName {
     pub fn has_table_of(&self, other: &ClauseName) -> bool {
         match self {
             ClauseName::BuiltIn(_) => {
-                if let ClauseName::BuiltIn(_) = other {
+                matches!(other, ClauseName::BuiltIn(_))
-                    true
-                } else {
-                    false
-                }
-            }
-            ClauseName::User(ref name) => {
-                other.has_table(&name.table)
             }
+            ClauseName::User(ref name) => other.has_table(&name.table),
         }
     }
 
     #[inline]
     pub fn as_str(&self) -> &str {
         match self {
-            &ClauseName::BuiltIn(s) => s,
+            ClauseName::BuiltIn(s) => s,
-            &ClauseName::User(ref name) => name.as_ref()
+            ClauseName::User(ref name) => name.as_ref(),
         }
     }
 
     #[inline]
     pub fn is_char(&self) -> bool {
-        !self.as_str().is_empty() && self.as_str().chars().skip(1).next().is_none()
+        !self.as_str().is_empty() && self.as_str().chars().nth(1).is_none()
     }
 
-    pub fn defrock_brackets(self) -> Self {
+    pub fn defrock_brackets(&self) -> Self {
         fn defrock_brackets(s: &str) -> &str {
             if s.starts_with('(') && s.ends_with(')') {
-                &s[1 .. s.len() - 1]
+                &s[1..s.len() - 1]
             } else {
                 s
             }
         }
 
         match self {
-            ClauseName::BuiltIn(s) =>
+            ClauseName::BuiltIn(s) => ClauseName::BuiltIn(defrock_brackets(s)),
-                ClauseName::BuiltIn(defrock_brackets(s)),
+            ClauseName::User(s) => {
-            ClauseName::User(s) =>
                 ClauseName::User(tabled_rc!(defrock_brackets(s.as_str()).to_owned(), s.table))
+            }
         }
     }
 }
 
 impl AsRef<str> for ClauseName {
     #[inline]
-    fn as_ref(self: &Self) -> &str {
+    fn as_ref(&self) -> &str {
         self.as_str()
     }
 }
@@ -713,41 +706,45 @@ impl AsRef<str> for ClauseName {
 #[derive(Debug, PartialEq, Eq, Clone)]
 pub enum Term {
     AnonVar,
-    Clause(Cell<RegType>, ClauseName, Vec<Box<Term>>, Option<SharedOpDesc>),
+    Clause(
+        Cell<RegType>,
+        ClauseName,
+        Vec<Box<Term>>,
+        Option<SharedOpDesc>,
+    ),
     Cons(Cell<RegType>, Box<Term>, Box<Term>),
     Constant(Cell<RegType>, Constant),
-    Var(Cell<VarReg>, Rc<Var>)
+    Var(Cell<VarReg>, Rc<Var>),
 }
 
 impl Term {
     pub fn shared_op_desc(&self) -> Option<SharedOpDesc> {
         match self {
-            &Term::Clause(_, _, _, ref spec) => spec.clone(),
+            Term::Clause(_, _, _, ref spec) => spec.clone(),
-            &Term::Constant(_, Constant::Atom(_, ref spec)) => spec.clone(),
+            Term::Constant(_, Constant::Atom(_, ref spec)) => spec.clone(),
-            _ => None
+            _ => None,
         }
     }
 
-    pub fn to_constant(self) -> Option<Constant> {
+    pub fn into_constant(self) -> Option<Constant> {
         match self {
             Term::Constant(_, c) => Some(c),
-            _ => None
+            _ => None,
         }
     }
 
     pub fn first_arg(&self) -> Option<&Term> {
         match self {
-            &Term::Clause(_, _, ref terms, _) =>
+            Term::Clause(_, _, ref terms, _) => terms.first().map(|bt| bt.as_ref()),
-                terms.first().map(|bt| bt.as_ref()),
+            _ => None,
-            _ => None
         }
     }
 
     pub fn set_name(&mut self, new_name: ClauseName) {
         match self {
             Term::Constant(_, Constant::Atom(ref mut atom, _))
-          | Term::Clause(_, ref mut atom, ..) => {
+            | Term::Clause(_, ref mut atom, ..) => {
-              *atom = new_name;
+                *atom = new_name;
             }
             _ => {}
         }
@@ -755,22 +752,23 @@ impl Term {
 
     pub fn name(&self) -> Option<ClauseName> {
         match self {
-            &Term::Constant(_, Constant::Atom(ref atom, _))
+            &Term::Constant(_, Constant::Atom(ref atom, _)) | &Term::Clause(_, ref atom, ..) => {
-          | &Term::Clause(_, ref atom, ..) => Some(atom.clone()),
+                Some(atom.clone())
-            _ => None
+            }
+            _ => None,
         }
     }
 
     pub fn arity(&self) -> usize {
         match self {
-            &Term::Clause(_, _, ref child_terms, ..) => child_terms.len(),
+            Term::Clause(_, _, ref child_terms, ..) => child_terms.len(),
-            _ => 0
+            _ => 0,
         }
     }
 }
 
 fn unfold_by_str_once(term: &mut Term, s: &str) -> Option<(Term, Term)> {
-    if let &mut Term::Clause(_, ref name, ref mut subterms, _) = term {
+    if let Term::Clause(_, ref name, ref mut subterms, _) = term {
         if name.as_str() == s && subterms.len() == 2 {
             let snd = *subterms.pop().unwrap();
             let fst = *subterms.pop().unwrap();

crates/prolog_parser/src/lexer.rs

@@ -1,9 +1,9 @@
-use crate::lexical::parse_lossy;
-use crate::ordered_float::*;
 use crate::rug::Integer;
+use lexical::parse_lossy;
+use ordered_float::*;
 
-use ast::*;
+use crate::ast::*;
-use tabled_rc::*;
+use crate::tabled_rc::*;
 
 use std::convert::TryFrom;
 use std::fmt;
@@ -11,13 +11,13 @@ use std::io::Read;
 use std::rc::Rc;
 
 macro_rules! is_not_eof {
-    ($c:expr) => (
+    ($c:expr) => {
         match $c {
             Ok(c) => c,
-            Err(ParserError::UnexpectedEOF) => return Ok(true),
+            Err($crate::ast::ParserError::UnexpectedEOF) => return Ok(true),
-            Err(e) => return Err(e)
+            Err(e) => return Err(e),
         }
-    )
+    };
 }
 
 macro_rules! consume_chars_with {
@@ -26,27 +26,27 @@ macro_rules! consume_chars_with {
             match $e {
                 Ok(Some(c)) => $token.push(c),
                 Ok(None) => continue,
-                Err(ParserError::UnexpectedChar(..)) => break,
+                Err($crate::ast::ParserError::UnexpectedChar(..)) => break,
-                Err(e) => return Err(e)
+                Err(e) => return Err(e),
             }
         }
-    }
+    };
 }
 
 #[derive(Debug, Clone, PartialEq)]
 pub enum Token {
     Constant(Constant),
     Var(Rc<Atom>),
-    Open,           // '('
+    Open,              // '('
-    OpenCT,         // '('
+    OpenCT,            // '('
-    Close,          // ')'
+    Close,             // ')'
-    OpenList,       // '['
+    OpenList,          // '['
-    CloseList,      // ']'
+    CloseList,         // ']'
-    OpenCurly,      // '{'
+    OpenCurly,         // '{'
-    CloseCurly,     // '}'
+    CloseCurly,        // '}'
     HeadTailSeparator, // '|'
-    Comma,          // ','
+    Comma,             // ','
-    End
+    End,
 }
 
 pub struct Lexer<'a, R: Read> {
@@ -54,17 +54,17 @@ pub struct Lexer<'a, R: Read> {
     pub(crate) reader: &'a mut ParsingStream<R>,
     pub(crate) flags: MachineFlags,
     pub(crate) line_num: usize,
-    pub(crate) col_num: usize
+    pub(crate) col_num: usize,
 }
 
 impl<'a, R: Read + fmt::Debug> fmt::Debug for Lexer<'a, R> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Lexer")
-         .field("atom_tbl", &self.atom_tbl)
+            .field("atom_tbl", &self.atom_tbl)
-         .field("reader", &"&'a mut ParsingStream<R>")  // Hacky solution.
+            .field("reader", &"&'a mut ParsingStream<R>") // Hacky solution.
-         .field("line_num", &self.line_num)
+            .field("line_num", &self.line_num)
-         .field("col_num", &self.col_num)
+            .field("col_num", &self.col_num)
-         .finish()
+            .finish()
     }
 }
 
@@ -74,7 +74,13 @@ impl<'a, R: Read> Lexer<'a, R> {
         flags: MachineFlags,
         src: &'a mut ParsingStream<R>,
     ) -> Self {
-        Lexer { atom_tbl, flags, reader: src, line_num: 0, col_num: 0 }
+        Lexer {
+            atom_tbl,
+            flags,
+            reader: src,
+            line_num: 0,
+            col_num: 0,
+        }
     }
 
     fn return_char(&mut self, c: char) {
@@ -128,8 +134,7 @@ impl<'a, R: Read> Lexer<'a, R> {
         }
     }
 
-    fn single_line_comment(&mut self) -> Result<(), ParserError>
+    fn single_line_comment(&mut self) -> Result<(), ParserError> {
-    {
         loop {
             if self.reader.peek().is_none() || new_line_char!(self.skip_char()?) {
                 break;
@@ -229,8 +234,7 @@ impl<'a, R: Read> Lexer<'a, R> {
         }
     }
 
-    fn get_single_quoted_item(&mut self) -> Result<Option<char>, ParserError>
+    fn get_single_quoted_item(&mut self) -> Result<Option<char>, ParserError> {
-    {
         if backslash_char!(self.lookahead_char()?) {
             let c = self.skip_char()?;
 
@@ -264,14 +268,13 @@ impl<'a, R: Read> Lexer<'a, R> {
         }
     }
 
-    fn get_double_quoted_item(&mut self) -> Result<Option<char>, ParserError>
+    fn get_double_quoted_item(&mut self) -> Result<Option<char>, ParserError> {
-    {
         if backslash_char!(self.lookahead_char()?) {
             let c = self.skip_char()?;
 
             if new_line_char!(self.lookahead_char()?) {
                 self.skip_char()?;
-                return Ok(None)
+                return Ok(None);
             } else {
                 self.return_char(c);
             }
@@ -299,8 +302,7 @@ impl<'a, R: Read> Lexer<'a, R> {
         }
     }
 
-    fn get_control_escape_sequence(&mut self) -> Result<char, ParserError>
+    fn get_control_escape_sequence(&mut self) -> Result<char, ParserError> {
-    {
         let escaped = match self.lookahead_char()? {
             'a' => '\u{07}', // UTF-8 alert
             'b' => '\u{08}', // UTF-8 backspace
@@ -309,20 +311,18 @@ impl<'a, R: Read> Lexer<'a, R> {
             't' => '\t',
             'n' => '\n',
             'r' => '\r',
-            c   => return Err(ParserError::UnexpectedChar(c, self.line_num, self.col_num))
+            c => return Err(ParserError::UnexpectedChar(c, self.line_num, self.col_num)),
         };
 
         self.skip_char()?;
         return Ok(escaped);
     }
 
-    fn get_octal_escape_sequence(&mut self) -> Result<char, ParserError>
+    fn get_octal_escape_sequence(&mut self) -> Result<char, ParserError> {
-    {
         self.escape_sequence_to_char(|c| octal_digit_char!(c), 8)
     }
 
-    fn get_hexadecimal_escape_sequence(&mut self) -> Result<char, ParserError>
+    fn get_hexadecimal_escape_sequence(&mut self) -> Result<char, ParserError> {
-    {
         self.skip_char()?;
         let c = self.lookahead_char()?;
 
@@ -354,12 +354,13 @@ impl<'a, R: Read> Lexer<'a, R> {
 
         if backslash_char!(c) {
             self.skip_char()?;
-            u32::from_str_radix(&token, radix)
+            u32::from_str_radix(&token, radix).map_or_else(
-                .map_or_else(
+                |_| Err(ParserError::ParseBigInt(self.line_num, self.col_num)),
-                    |_| Err(ParserError::ParseBigInt(self.line_num, self.col_num)),
+                |n| {
-                    |n| char::try_from(n)
+                    char::try_from(n)
                         .map_err(|_| ParserError::Utf8Error(self.line_num, self.col_num))
-                )
+                },
+            )
         } else {
             // on failure, restore the token characters and backslash.
             self.reader.put_back_all(token.chars().map(Ok));
@@ -423,11 +424,8 @@ impl<'a, R: Read> Lexer<'a, R> {
                 .map(|n| Token::Constant(Constant::Fixnum(n)))
                 .or_else(|_| {
                     Integer::from_str_radix(&token, 16)
-                         .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
+                        .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
-                         .map_err(|_| ParserError::ParseBigInt(
+                        .map_err(|_| ParserError::ParseBigInt(self.line_num, self.col_num))
-                             self.line_num,
-                             self.col_num,
-                         ))
                 })
         } else {
             self.return_char('x');
@@ -449,11 +447,8 @@ impl<'a, R: Read> Lexer<'a, R> {
                 .map(|n| Token::Constant(Constant::Fixnum(n)))
                 .or_else(|_| {
                     Integer::from_str_radix(&token, 8)
-                         .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
+                        .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
-                         .map_err(|_| ParserError::ParseBigInt(
+                        .map_err(|_| ParserError::ParseBigInt(self.line_num, self.col_num))
-                             self.line_num,
-                             self.col_num,
-                         ))
                 })
         } else {
             self.return_char('o');
@@ -475,11 +470,8 @@ impl<'a, R: Read> Lexer<'a, R> {
                 .map(|n| Token::Constant(Constant::Fixnum(n)))
                 .or_else(|_| {
                     Integer::from_str_radix(&token, 2)
-                         .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
+                        .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
-                         .map_err(|_| ParserError::ParseBigInt(
+                        .map_err(|_| ParserError::ParseBigInt(self.line_num, self.col_num))
-                             self.line_num,
-                             self.col_num,
-                         ))
                 })
         } else {
             self.return_char('b');
@@ -525,18 +517,20 @@ impl<'a, R: Read> Lexer<'a, R> {
             if single_quote_char!(self.lookahead_char()?) {
                 self.skip_char()?;
 
-                if !token.is_empty() && token.chars().skip(1).next().is_none() {
+                if !token.is_empty() && token.chars().nth(1).is_none() {
                     if let Some(c) = token.chars().next() {
                         return Ok(Token::Constant(Constant::Char(c)));
                     }
                 }
             } else {
-                return Err(ParserError::InvalidSingleQuotedCharacter(self.lookahead_char()?))
+                return Err(ParserError::InvalidSingleQuotedCharacter(
+                    self.lookahead_char()?,
+                ));
             }
         } else {
             match self.get_back_quoted_string() {
-                Ok(_)  => return Err(ParserError::BackQuotedString(self.line_num, self.col_num)),
+                Ok(_) => return Err(ParserError::BackQuotedString(self.line_num, self.col_num)),
-                Err(e) => return Err(e)
+                Err(e) => return Err(e),
             }
         }
 
@@ -575,12 +569,10 @@ impl<'a, R: Read> Lexer<'a, R> {
                 isize::from_str_radix(&token, 10)
                     .map(|n| Token::Constant(Constant::Fixnum(n)))
                     .or_else(|_| {
-                        token.parse::<Integer>()
+                        token
-                             .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
+                            .parse::<Integer>()
-                             .map_err(|_| ParserError::ParseBigInt(
+                            .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
-                                 self.line_num,
+                            .map_err(|_| ParserError::ParseBigInt(self.line_num, self.col_num))
-                                 self.col_num,
-                             ))
                     })
             } else if decimal_digit_char!(self.lookahead_char()?) {
                 token.push('.');
@@ -599,7 +591,7 @@ impl<'a, R: Read> Lexer<'a, R> {
 
                     let c = match self.lookahead_char() {
                         Err(_) => return Ok(self.vacate_with_float(token)),
-                        Ok(c) => c
+                        Ok(c) => c,
                     };
 
                     if !sign_char!(c) && !decimal_digit_char!(c) {
@@ -613,8 +605,8 @@ impl<'a, R: Read> Lexer<'a, R> {
                             Err(_) => {
                                 self.return_char(token.pop().unwrap());
                                 return Ok(self.vacate_with_float(token));
-                            },
+                            }
-                            Ok(c) => c
+                            Ok(c) => c,
                         };
 
                         if !decimal_digit_char!(c) {
@@ -645,70 +637,65 @@ impl<'a, R: Read> Lexer<'a, R> {
                 isize::from_str_radix(&token, 10)
                     .map(|n| Token::Constant(Constant::Fixnum(n)))
                     .or_else(|_| {
-                        token.parse::<Integer>()
+                        token
-                             .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
+                            .parse::<Integer>()
-                             .map_err(|_| ParserError::ParseBigInt(
+                            .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
-                                 self.line_num,
+                            .map_err(|_| ParserError::ParseBigInt(self.line_num, self.col_num))
-                                 self.col_num,
-                             ))
                     })
             }
         } else {
             if token.starts_with('0') && token.len() == 1 {
                 if c == 'x' {
-                    self.hexadecimal_constant()
+                    self.hexadecimal_constant().or_else(|e| {
-                        .or_else(|e| {
+                        if let ParserError::ParseBigInt(..) = e {
-                            if let ParserError::ParseBigInt(..) = e {
+                            isize::from_str_radix(&token, 10)
-                                isize::from_str_radix(&token, 10)
+                                .map(|n| Token::Constant(Constant::Fixnum(n)))
-                                    .map(|n| Token::Constant(Constant::Fixnum(n)))
+                                .or_else(|_| {
-                                    .or_else(|_| {
+                                    token
-                                        token.parse::<Integer>()
+                                        .parse::<Integer>()
-                                             .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
+                                        .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
-                                             .map_err(|_| ParserError::ParseBigInt(
+                                        .map_err(|_| {
-                                                 self.line_num,
+                                            ParserError::ParseBigInt(self.line_num, self.col_num)
-                                                 self.col_num,
+                                        })
-                                             ))
+                                })
-                                    })
+                        } else {
-                            } else {
+                            Err(e)
-                                Err(e)
+                        }
-                            }
+                    })
-                        })
                 } else if c == 'o' {
-                    self.octal_constant()
+                    self.octal_constant().or_else(|e| {
-                        .or_else(|e| {
+                        if let ParserError::ParseBigInt(..) = e {
-                            if let ParserError::ParseBigInt(..) = e {
+                            isize::from_str_radix(&token, 10)
-                                isize::from_str_radix(&token, 10)
+                                .map(|n| Token::Constant(Constant::Fixnum(n)))
-                                    .map(|n| Token::Constant(Constant::Fixnum(n)))
+                                .or_else(|_| {
-                                    .or_else(|_| {
+                                    token
-                                        token.parse::<Integer>()
+                                        .parse::<Integer>()
-                                            .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
+                                        .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
-                                            .map_err(|_| ParserError::ParseBigInt(
+                                        .map_err(|_| {
-                                                self.line_num,
+                                            ParserError::ParseBigInt(self.line_num, self.col_num)
-                                                self.col_num,
+                                        })
-                                            ))
+                                })
-                                    })
+                        } else {
-                            } else {
+                            Err(e)
-                                Err(e)
+                        }
-                            }
+                    })
-                        })
                 } else if c == 'b' {
-                    self.binary_constant()
+                    self.binary_constant().or_else(|e| {
-                        .or_else(|e| {
+                        if let ParserError::ParseBigInt(..) = e {
-                            if let ParserError::ParseBigInt(..) = e {
+                            isize::from_str_radix(&token, 10)
-                                isize::from_str_radix(&token, 10)
+                                .map(|n| Token::Constant(Constant::Fixnum(n)))
-                                    .map(|n| Token::Constant(Constant::Fixnum(n)))
+                                .or_else(|_| {
-                                    .or_else(|_| {
+                                    token
-                                        token.parse::<Integer>()
+                                        .parse::<Integer>()
-                                             .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
+                                        .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
-                                             .map_err(|_| ParserError::ParseBigInt(
+                                        .map_err(|_| {
-                                                 self.line_num,
+                                            ParserError::ParseBigInt(self.line_num, self.col_num)
-                                                 self.col_num,
+                                        })
-                                             ))
+                                })
-                                    })
+                        } else {
-                            } else {
+                            Err(e)
-                                Err(e)
+                        }
-                            }
+                    })
-                        })
                 } else if single_quote_char!(c) {
                     self.skip_char()?;
 
@@ -726,45 +713,39 @@ impl<'a, R: Read> Lexer<'a, R> {
                     }
 
                     self.get_single_quoted_char()
-                        .and_then(|c| {
+                        .map(|c| Token::Constant(Constant::Fixnum(c as isize)))
-                            Ok(Token::Constant(Constant::Fixnum(c as isize)))
-                        })
                         .or_else(|_| {
                             self.return_char(c);
 
                             isize::from_str_radix(&token, 10)
                                 .map(|n| Token::Constant(Constant::Fixnum(n)))
                                 .or_else(|_| {
-                                    token.parse::<Integer>()
+                                    token
-                                         .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
+                                        .parse::<Integer>()
-                                         .map_err(|_| ParserError::ParseBigInt(
+                                        .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
-                                             self.line_num,
+                                        .map_err(|_| {
-                                             self.col_num,
+                                            ParserError::ParseBigInt(self.line_num, self.col_num)
-                                         ))
+                                        })
                                 })
                         })
                 } else {
                     isize::from_str_radix(&token, 10)
                         .map(|n| Token::Constant(Constant::Fixnum(n)))
                         .or_else(|_| {
-                            token.parse::<Integer>()
+                            token
-                                 .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
+                                .parse::<Integer>()
-                                 .map_err(|_| ParserError::ParseBigInt(
+                                .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
-                                     self.line_num,
+                                .map_err(|_| ParserError::ParseBigInt(self.line_num, self.col_num))
-                                     self.col_num,
-                                 ))
                         })
                 }
             } else {
                 isize::from_str_radix(&token, 10)
                     .map(|n| Token::Constant(Constant::Fixnum(n)))
                     .or_else(|_| {
-                        token.parse::<Integer>()
+                        token
-                             .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
+                            .parse::<Integer>()
-                             .map_err(|_| ParserError::ParseBigInt(
+                            .map(|n| Token::Constant(Constant::Integer(Rc::new(n))))
-                                 self.line_num,
+                            .map_err(|_| ParserError::ParseBigInt(self.line_num, self.col_num))
-                                 self.col_num,
-                             ))
                     })
             }
         }
@@ -781,18 +762,19 @@ impl<'a, R: Read> Lexer<'a, R> {
                 Ok(c) if layout_char!(c) || new_line_char!(c) => {
                     self.skip_char()?;
                     layout_inserted = true;
-                },
+                }
                 Ok(c) if end_line_comment_char!(c) => {
                     self.single_line_comment()?;
                     layout_inserted = true;
-                },
+                }
-                Ok(c) if comment_1_char!(c) =>
+                Ok(c) if comment_1_char!(c) => {
                     if self.bracketed_comment()? {
                         layout_inserted = true;
                     } else {
                         more_layout = false;
-                    },
+                    }
-                _ => more_layout = false
+                }
+                _ => more_layout = false,
             };
 
             if !more_layout {
@@ -825,8 +807,11 @@ impl<'a, R: Read> Lexer<'a, R> {
 
                 if c == '(' {
                     self.skip_char()?;
-                    return Ok(if layout_inserted { Token::Open }
+                    return Ok(if layout_inserted {
-                              else { Token::OpenCT });
+                        Token::Open
+                    } else {
+                        Token::OpenCT
+                    });
                 }
 
                 if c == '.' {
@@ -839,7 +824,7 @@ impl<'a, R: Read> Lexer<'a, R> {
                             }
 
                             return Ok(Token::End);
-                        },
+                        }
                         Err(ParserError::UnexpectedEOF) => {
                             return Ok(Token::End);
                         }
@@ -891,8 +876,8 @@ impl<'a, R: Read> Lexer<'a, R> {
                 }
 
                 self.name_token(c)
-            },
+            }
-            Err(e) => Err(e)
+            Err(e) => Err(e),
         }
     }
 }

crates/prolog_parser/src/lib.rs

@@ -1,14 +1,14 @@
-extern crate lexical;
-extern crate ordered_float;
-#[cfg(feature = "rug")]
-extern crate rug;
 #[cfg(feature = "num-rug-adapter")]
-extern crate num_rug_adapter as rug;
+use num_rug_adapter as rug;
-extern crate unicode_reader;
+#[cfg(feature = "rug")]
+use rug;
 
-#[macro_use] pub mod tabled_rc;
+#[macro_use]
-#[macro_use] pub mod ast;
+pub mod tabled_rc;
-#[macro_use] pub mod macros;
+#[macro_use]
+pub mod ast;
+#[macro_use]
+pub mod macros;
 pub mod parser;
 pub mod put_back_n;
 

crates/prolog_parser/src/macros.rs

@@ -1,187 +1,246 @@
 #[macro_export]
 macro_rules! char_class {
     ($c: expr, [$head:expr]) => ($c == $head);
-    ($c: expr, [$head:expr $(, $cs:expr)+]) => ($c == $head || char_class!($c, [$($cs),*]));
+    ($c: expr, [$head:expr $(, $cs:expr)+]) => ($c == $head || $crate::char_class!($c, [$($cs),*]));
 }
 
 #[macro_export]
 macro_rules! symbolic_control_char {
-    ($c: expr) => (char_class!($c, ['a', 'b', 'f', 'n', 'r', 't', 'v', '0']))
+    ($c: expr) => {
+        $crate::char_class!($c, ['a', 'b', 'f', 'n', 'r', 't', 'v', '0'])
+    };
 }
 
 #[macro_export]
 macro_rules! space_char {
-    ($c: expr) => ($c == ' ')
+    ($c: expr) => {
+        $c == ' '
+    };
 }
 
 #[macro_export]
 macro_rules! layout_char {
-    ($c: expr) => (char_class!($c, [' ', '\n', '\t', '\u{0B}', '\u{0C}']))
+    ($c: expr) => {
+        $crate::char_class!($c, [' ', '\n', '\t', '\u{0B}', '\u{0C}'])
+    };
 }
 
 #[macro_export]
 macro_rules! symbolic_hexadecimal_char {
-    ($c: expr) => ($c == 'x')
+    ($c: expr) => {
+        $c == 'x'
+    };
 }
 
 #[macro_export]
 macro_rules! octal_digit_char {
-    ($c: expr) => ($c >= '0' && $c <= '7')
+    ($c: expr) => {
+        ('0'..='7').contains(&$c)
+    };
 }
 
 #[macro_export]
 macro_rules! binary_digit_char {
-    ($c: expr) => ($c >= '0' && $c <= '1')
+    ($c: expr) => {
+        $c >= '0' && $c <= '1'
+    };
 }
 
 #[macro_export]
 macro_rules! hexadecimal_digit_char {
-    ($c: expr) => ($c >= '0' && $c <= '9' ||
+    ($c: expr) => {
-                   $c >= 'A' && $c <= 'F' ||
+        ('0'..='9').contains(&$c) || ('A'..='F').contains(&$c) || ('a'..='f').contains(&$c)
-                   $c >= 'a' && $c <= 'f')
+    };
 }
 
 #[macro_export]
 macro_rules! exponent_char {
-    ($c: expr) => ($c == 'e' || $c == 'E')
+    ($c: expr) => {
+        $c == 'e' || $c == 'E'
+    };
 }
 
 #[macro_export]
 macro_rules! sign_char {
-    ($c: expr) => ($c == '-' || $c == '+')
+    ($c: expr) => {
+        $c == '-' || $c == '+'
+    };
 }
 
 #[macro_export]
 macro_rules! new_line_char {
-    ($c: expr) => ($c == '\n')
+    ($c: expr) => {
+        $c == '\n'
+    };
 }
 
 #[macro_export]
 macro_rules! end_line_comment_char {
-    ($c: expr) => ($c == '%')
+    ($c: expr) => {
+        $c == '%'
+    };
 }
 
 #[macro_export]
 macro_rules! comment_1_char {
-    ($c: expr) => ($c == '/')
+    ($c: expr) => {
+        $c == '/'
+    };
 }
 
 #[macro_export]
 macro_rules! comment_2_char {
-    ($c: expr) => ($c == '*')
+    ($c: expr) => {
+        $c == '*'
+    };
 }
 
 #[macro_export]
 macro_rules! capital_letter_char {
-    ($c: expr) => ($c >= 'A' && $c <= 'Z')
+    ($c: expr) => {
+        ('A'..='Z').contains(&$c)
+    };
 }
 
 #[macro_export]
 macro_rules! small_letter_char {
-    ($c: expr) => ($c >= 'a' && $c <= 'z')
+    ($c: expr) => {
+        ('a'..='z').contains(&$c)
+    };
 }
 
 #[macro_export]
 macro_rules! variable_indicator_char {
-    ($c: expr) => ($c == '_')
+    ($c: expr) => {
+        $c == '_'
+    };
 }
 
 #[macro_export]
 macro_rules! graphic_char {
-    ($c: expr) => (char_class!($c, ['#', '$', '&', '*', '+', '-', '.', '/', ':',
+    ($c: expr) => ($crate::char_class!($c, ['#', '$', '&', '*', '+', '-', '.', '/', ':',
                                     '<', '=', '>', '?', '@', '^', '~']))
 }
 
 #[macro_export]
 macro_rules! graphic_token_char {
-    ($c: expr) => (graphic_char!($c) || backslash_char!($c))
+    ($c: expr) => {
+        $crate::graphic_char!($c) || $crate::backslash_char!($c)
+    };
 }
 
 #[macro_export]
 macro_rules! alpha_char {
-    ($c: expr) =>
+    ($c: expr) => {
-        (match $c {
+        match $c {
-            'a' ..= 'z' => true,
+            'a'..='z' => true,
-            'A' ..= 'Z' => true,
+            'A'..='Z' => true,
             '_' => true,
-            '\u{00A0}' ..= '\u{00BF}' => true,
+            '\u{00A0}'..='\u{00BF}' => true,
-            '\u{00C0}' ..= '\u{00D6}' => true,
+            '\u{00C0}'..='\u{00D6}' => true,
-            '\u{00D8}' ..= '\u{00F6}' => true,
+            '\u{00D8}'..='\u{00F6}' => true,
-            '\u{00F8}' ..= '\u{00FF}' => true,
+            '\u{00F8}'..='\u{00FF}' => true,
-            '\u{0100}' ..= '\u{017F}' => true, // Latin Extended-A
+            '\u{0100}'..='\u{017F}' => true, // Latin Extended-A
-            '\u{0180}' ..= '\u{024F}' => true, // Latin Extended-B
+            '\u{0180}'..='\u{024F}' => true, // Latin Extended-B
-            '\u{0250}' ..= '\u{02AF}' => true, // IPA Extensions
+            '\u{0250}'..='\u{02AF}' => true, // IPA Extensions
-            '\u{02B0}' ..= '\u{02FF}' => true, // Spacing Modifier Letters
+            '\u{02B0}'..='\u{02FF}' => true, // Spacing Modifier Letters
-            '\u{0300}' ..= '\u{036F}' => true, // Combining Diacritical Marks
+            '\u{0300}'..='\u{036F}' => true, // Combining Diacritical Marks
-            '\u{0370}' ..= '\u{03FF}' => true, // Greek/Coptic
+            '\u{0370}'..='\u{03FF}' => true, // Greek/Coptic
-            '\u{0400}' ..= '\u{04FF}' => true, // Cyrillic
+            '\u{0400}'..='\u{04FF}' => true, // Cyrillic
-            '\u{0500}' ..= '\u{052F}' => true, // Cyrillic Supplement
+            '\u{0500}'..='\u{052F}' => true, // Cyrillic Supplement
-            '\u{0530}' ..= '\u{058F}' => true, // Armenian
+            '\u{0530}'..='\u{058F}' => true, // Armenian
-            '\u{0590}' ..= '\u{05FF}' => true, // Hebrew
+            '\u{0590}'..='\u{05FF}' => true, // Hebrew
-            '\u{0600}' ..= '\u{06FF}' => true, // Arabic
+            '\u{0600}'..='\u{06FF}' => true, // Arabic
-            '\u{0700}' ..= '\u{074F}' => true, // Syriac
+            '\u{0700}'..='\u{074F}' => true, // Syriac
-            _ => false
+            _ => false,
-        })
+        }
+    };
 }
 
 #[macro_export]
 macro_rules! decimal_digit_char {
-    ($c: expr) => ($c >= '0' && $c <= '9')
+    ($c: expr) => {
+        ('0'..='9').contains(&$c)
+    };
 }
 
 #[macro_export]
 macro_rules! decimal_point_char {
-    ($c: expr) => ($c == '.')
+    ($c: expr) => {
+        $c == '.'
+    };
 }
 
 #[macro_export]
 macro_rules! alpha_numeric_char {
-    ($c: expr) => (alpha_char!($c) || decimal_digit_char!($c))
+    ($c: expr) => {
+        $crate::alpha_char!($c) || $crate::decimal_digit_char!($c)
+    };
 }
 
 #[macro_export]
 macro_rules! cut_char {
-    ($c: expr) => ($c == '!')
+    ($c: expr) => {
+        $c == '!'
+    };
 }
 
 #[macro_export]
 macro_rules! semicolon_char {
-    ($c: expr) => ($c == ';')
+    ($c: expr) => {
+        $c == ';'
+    };
 }
 
 #[macro_export]
 macro_rules! backslash_char {
-    ($c: expr) => ($c == '\\')
+    ($c: expr) => {
+        $c == '\\'
+    };
 }
 
 #[macro_export]
 macro_rules! single_quote_char {
-    ($c: expr) => ($c == '\'')
+    ($c: expr) => {
+        $c == '\''
+    };
 }
 
 #[macro_export]
 macro_rules! double_quote_char {
-    ($c: expr) => ($c == '"')
+    ($c: expr) => {
+        $c == '"'
+    };
 }
 
 #[macro_export]
 macro_rules! back_quote_char {
-    ($c: expr) => ($c == '`')
+    ($c: expr) => {
+        $c == '`'
+    };
 }
 
 #[macro_export]
 macro_rules! meta_char {
-    ($c: expr) => ( char_class!($c, ['\\', '\'', '"', '`']) )
+    ($c: expr) => {
+        $crate::char_class!($c, ['\\', '\'', '"', '`'])
+    };
 }
 
 #[macro_export]
 macro_rules! solo_char {
-    ($c: expr) => ( char_class!($c, ['!', '(', ')', ',', ';', '[', ']',
+    ($c: expr) => {
-                                     '{', '}', '|', '%']) )
+        $crate::char_class!($c, ['!', '(', ')', ',', ';', '[', ']', '{', '}', '|', '%'])
+    };
 }
 
 #[macro_export]
 macro_rules! prolog_char {
-    ($c: expr) => (graphic_char!($c) || alpha_numeric_char!($c) || solo_char!($c) ||
+    ($c: expr) => {
-                   layout_char!($c) || meta_char!($c))
+        $crate::graphic_char!($c)
+            || $crate::alpha_numeric_char!($c)
+            || $crate::solo_char!($c)
+            || $crate::layout_char!($c)
+            || $crate::meta_char!($c)
+    };
 }

crates/prolog_parser/src/parser.rs

@@ -1,10 +1,10 @@
-use ast::*;
+use crate::ast::*;
-use lexer::*;
+use crate::lexer::*;
-use tabled_rc::*;
+use crate::tabled_rc::*;
 
 use ordered_float::OrderedFloat;
 
-use rug::ops::NegAssign;
+use crate::rug::ops::NegAssign;
 
 use std::cell::Cell;
 use std::io::Read;
@@ -16,25 +16,30 @@ enum TokenType {
     Term,
     Open,
     OpenCT,
-    OpenList,       // '['
+    OpenList,          // '['
-    OpenCurly,      // '{'
+    OpenCurly,         // '{'
     HeadTailSeparator, // '|'
-    Comma,          // ','
+    Comma,             // ','
     Close,
-    CloseList,      // ']'
+    CloseList,  // ']'
-    CloseCurly,     // '}'
+    CloseCurly, // '}'
-    End
+    End,
 }
 
 impl TokenType {
     fn is_sep(self) -> bool {
-        match self {
+        matches!(
-            TokenType::HeadTailSeparator | TokenType::OpenCT | TokenType::Open |
+            self,
-            TokenType::Close | TokenType::OpenList | TokenType::CloseList |
+            TokenType::HeadTailSeparator
-            TokenType::OpenCurly | TokenType::CloseCurly | TokenType::Comma
+                | TokenType::OpenCT
-                => true,
+                | TokenType::Open
-            _   => false
+                | TokenType::Close
-        }
+                | TokenType::OpenList
+                | TokenType::CloseList
+                | TokenType::OpenCurly
+                | TokenType::CloseCurly
+                | TokenType::Comma
+        )
     }
 }
 
@@ -42,12 +47,14 @@ impl TokenType {
 struct TokenDesc {
     tt: TokenType,
     priority: usize,
-    spec: u32
+    spec: u32,
 }
 
-pub
+pub fn get_clause_spec(
-fn get_clause_spec(name: ClauseName, arity: usize, op_dir: &CompositeOpDir) -> Option<SharedOpDesc>
+    name: ClauseName,
-{
+    arity: usize,
+    op_dir: &CompositeOpDir,
+) -> Option<SharedOpDesc> {
     match arity {
         1 => {
             /* This is a clause with an operator principal functor. Prefix operators
@@ -60,20 +67,25 @@ fn get_clause_spec(name: ClauseName, arity: usize, op_dir: &CompositeOpDir) -> O
             if let Some(OpDirValue(cell)) = op_dir.get(name, Fixity::Post) {
                 return Some(cell.clone());
             }
-        },
+        }
-        2 =>
+        2 => {
             if let Some(OpDirValue(cell)) = op_dir.get(name, Fixity::In) {
                 return Some(cell.clone());
-            },
+            }
+        }
         _ => {}
     };
 
     None
 }
 
-pub fn get_op_desc(name: ClauseName, op_dir: &CompositeOpDir) -> Option<OpDesc>
+pub fn get_op_desc(name: ClauseName, op_dir: &CompositeOpDir) -> Option<OpDesc> {
-{
+    let mut op_desc = OpDesc {
-    let mut op_desc = OpDesc { pre: 0, inf: 0, post: 0, spec: 0 };
+        pre: 0,
+        inf: 0,
+        post: 0,
+        spec: 0,
+    };
 
     if let Some(OpDirValue(cell)) = op_dir.get(name.clone(), Fixity::Pre) {
         let (pri, spec) = cell.get();
@@ -111,8 +123,7 @@ pub fn get_op_desc(name: ClauseName, op_dir: &CompositeOpDir) -> Option<OpDesc>
     }
 }
 
-fn affirm_xfx(priority: usize, d2: TokenDesc, d3: TokenDesc, d1: TokenDesc) -> bool
+fn affirm_xfx(priority: usize, d2: TokenDesc, d3: TokenDesc, d1: TokenDesc) -> bool {
-{
     d2.priority <= priority
         && is_term!(d3.spec)
         && is_term!(d1.spec)
@@ -120,18 +131,15 @@ fn affirm_xfx(priority: usize, d2: TokenDesc, d3: TokenDesc, d1: TokenDesc) -> b
         && d1.priority < d2.priority
 }
 
-fn affirm_yfx(priority: usize, d2: TokenDesc, d3: TokenDesc, d1: TokenDesc) -> bool
+fn affirm_yfx(priority: usize, d2: TokenDesc, d3: TokenDesc, d1: TokenDesc) -> bool {
-{
     d2.priority <= priority
-        &&    ((is_term!(d3.spec) && d3.priority < d2.priority)
+        && ((is_term!(d3.spec) && d3.priority < d2.priority)
-           ||  (is_lterm!(d3.spec) && d3.priority == d2.priority))
+            || (is_lterm!(d3.spec) && d3.priority == d2.priority))
         && is_term!(d1.spec)
         && d1.priority < d2.priority
 }
 
-
+fn affirm_xfy(priority: usize, d2: TokenDesc, d3: TokenDesc, d1: TokenDesc) -> bool {
-fn affirm_xfy(priority: usize, d2: TokenDesc, d3: TokenDesc, d1: TokenDesc) -> bool
-{
     d2.priority < priority
         && is_term!(d3.spec)
         && d3.priority < d2.priority
@@ -139,49 +147,35 @@ fn affirm_xfy(priority: usize, d2: TokenDesc, d3: TokenDesc, d1: TokenDesc) -> b
         && d1.priority <= d2.priority
 }
 
-fn affirm_yf(d1: TokenDesc, d2: TokenDesc) -> bool
+fn affirm_yf(d1: TokenDesc, d2: TokenDesc) -> bool {
-{
     let is_valid_lterm = is_lterm!(d2.spec) && d2.priority == d1.priority;
     (is_term!(d2.spec) && d2.priority < d1.priority) || is_valid_lterm
 }
 
-fn affirm_xf(d1: TokenDesc, d2: TokenDesc) -> bool
+fn affirm_xf(d1: TokenDesc, d2: TokenDesc) -> bool {
-{
     is_term!(d2.spec) && d2.priority < d1.priority
 }
 
-fn affirm_fy(priority: usize, d1: TokenDesc, d2: TokenDesc) -> bool
+fn affirm_fy(priority: usize, d1: TokenDesc, d2: TokenDesc) -> bool {
-{
     d2.priority < priority && is_term!(d1.spec) && d1.priority <= d2.priority
 }
 
-fn affirm_fx(priority: usize, d1: TokenDesc, d2: TokenDesc) -> bool
+fn affirm_fx(priority: usize, d1: TokenDesc, d2: TokenDesc) -> bool {
-{
     d2.priority <= priority && is_term!(d1.spec) && d1.priority < d2.priority
 }
 
-fn sep_to_atom(tt: TokenType) -> Option<ClauseName>
+fn sep_to_atom(tt: TokenType) -> Option<ClauseName> {
-{
     match tt {
-        TokenType::Open | TokenType::OpenCT =>
+        TokenType::Open | TokenType::OpenCT => Some(clause_name!("(")),
-            Some(clause_name!("(")),
+        TokenType::Close => Some(clause_name!(")")),
-        TokenType::Close =>
+        TokenType::OpenList => Some(clause_name!("[")),
-            Some(clause_name!(")")),
+        TokenType::CloseList => Some(clause_name!("]")),
-        TokenType::OpenList =>
+        TokenType::OpenCurly => Some(clause_name!("{")),
-            Some(clause_name!("[")),
+        TokenType::CloseCurly => Some(clause_name!("}")),
-        TokenType::CloseList =>
+        TokenType::HeadTailSeparator => Some(clause_name!("|")),
-            Some(clause_name!("]")),
+        TokenType::Comma => Some(clause_name!(",")),
-        TokenType::OpenCurly =>
+        TokenType::End => Some(clause_name!(".")),
-            Some(clause_name!("{")),
+        _ => None,
-        TokenType::CloseCurly =>
-            Some(clause_name!("}")),
-        TokenType::HeadTailSeparator =>
-            Some(clause_name!("|")),
-        TokenType::Comma =>
-            Some(clause_name!(",")),
-        TokenType::End =>
-            Some(clause_name!(".")),
-        _ => None
     }
 }
 
@@ -190,7 +184,7 @@ pub struct OpDesc {
     pub pre: usize,
     pub inf: usize,
     pub post: usize,
-    pub spec: Specifier
+    pub spec: Specifier,
 }
 
 #[derive(Debug)]
@@ -201,8 +195,7 @@ pub struct Parser<'a, R: Read> {
     terms: Vec<Term>,
 }
 
-fn read_tokens<'a, R: Read>(lexer: &mut Lexer<'a, R>) -> Result<Vec<Token>, ParserError>
+fn read_tokens<R: Read>(lexer: &mut Lexer<R>) -> Result<Vec<Token>, ParserError> {
-{
     let mut tokens = vec![];
 
     loop {
@@ -227,10 +220,12 @@ impl<'a, R: Read> Parser<'a, R> {
         atom_tbl: TabledData<Atom>,
         flags: MachineFlags,
     ) -> Self {
-        Parser { lexer: Lexer::new(atom_tbl, flags, stream),
+        Parser {
-                 tokens: vec![],
+            lexer: Lexer::new(atom_tbl, flags, stream),
-                 stack:  Vec::new(),
+            tokens: vec![],
-                 terms:  Vec::new() }
+            stack: Vec::new(),
+            terms: Vec::new(),
+        }
     }
 
     #[inline]
@@ -255,50 +250,46 @@ impl<'a, R: Read> Parser<'a, R> {
 
     fn get_term_name(&mut self, td: TokenDesc) -> Option<(ClauseName, Option<SharedOpDesc>)> {
         match td.tt {
-            TokenType::HeadTailSeparator => {
+            TokenType::HeadTailSeparator => Some((
-                Some((clause_name!("|"), Some(SharedOpDesc::new(td.priority, td.spec))))
+                clause_name!("|"),
-            }
+                Some(SharedOpDesc::new(td.priority, td.spec)),
-            TokenType::Comma => {
+            )),
-                Some((clause_name!(","), Some(SharedOpDesc::new(1000, XFY))))
+            TokenType::Comma => Some((clause_name!(","), Some(SharedOpDesc::new(1000, XFY)))),
-            }
+            TokenType::Term => match self.terms.pop() {
-            TokenType::Term => {
+                Some(Term::Constant(_, Constant::Atom(atom, spec))) => Some((atom, spec)),
-                match self.terms.pop() {
+                Some(term) => {
-                    Some(Term::Constant(_, Constant::Atom(atom, spec))) =>
+                    self.terms.push(term);
-                        Some((atom, spec)),
+                    None
-                    Some(term) => {
-                        self.terms.push(term);
-                        None
-                    },
-                    _ => None
                 }
-            }
+                _ => None,
-            _ => {
+            },
-                None
+            _ => None,
-            }
         }
     }
 
-    fn push_binary_op(&mut self, td: TokenDesc, spec: Specifier)
+    fn push_binary_op(&mut self, td: TokenDesc, spec: Specifier) {
-    {
         if let Some(arg2) = self.terms.pop() {
             if let Some((name, shared_op_desc)) = self.get_term_name(td) {
                 if let Some(arg1) = self.terms.pop() {
-                    let term = Term::Clause(Cell::default(),
+                    let term = Term::Clause(
-                                            name,
+                        Cell::default(),
-                                            vec![Box::new(arg1), Box::new(arg2)],
+                        name,
-                                            shared_op_desc);
+                        vec![Box::new(arg1), Box::new(arg2)],
+                        shared_op_desc,
+                    );
 
                     self.terms.push(term);
-                    self.stack.push(TokenDesc { tt: TokenType::Term,
+                    self.stack.push(TokenDesc {
-                                                priority: td.priority,
+                        tt: TokenType::Term,
-                                                spec });
+                        priority: td.priority,
+                        spec,
+                    });
                 }
             }
         }
     }
 
-    fn push_unary_op(&mut self, td: TokenDesc, spec: Specifier, assoc: u32)
+    fn push_unary_op(&mut self, td: TokenDesc, spec: Specifier, assoc: u32) {
-    {
         if let Some(mut arg1) = self.terms.pop() {
             if let Some(mut name) = self.terms.pop() {
                 if is_postfix!(assoc) {
@@ -306,52 +297,61 @@ impl<'a, R: Read> Parser<'a, R> {
                 }
 
                 if let Term::Constant(_, Constant::Atom(name, shared_op_desc)) = name {
-                    let term = Term::Clause(Cell::default(), name, vec![Box::new(arg1)],
+                    let term =
-                                            shared_op_desc);
+                        Term::Clause(Cell::default(), name, vec![Box::new(arg1)], shared_op_desc);
 
                     self.terms.push(term);
-                    self.stack.push(TokenDesc { tt: TokenType::Term,
+                    self.stack.push(TokenDesc {
-                                                priority: td.priority,
+                        tt: TokenType::Term,
-                                                spec });
+                        priority: td.priority,
+                        spec,
+                    });
                 }
             }
         }
     }
 
-    fn promote_atom_op(&mut self, atom: ClauseName, priority: usize, assoc: u32,
+    fn promote_atom_op(
-                       op_dir_val: Option<&OpDirValue>)
+        &mut self,
-    {
+        atom: ClauseName,
+        priority: usize,
+        assoc: u32,
+        op_dir_val: Option<&OpDirValue>,
+    ) {
         let spec = op_dir_val.map(|op_dir_val| op_dir_val.shared_op_desc());
 
-        self.terms.push(Term::Constant(Cell::default(), Constant::Atom(atom, spec)));
+        self.terms
-        self.stack.push(TokenDesc { tt: TokenType::Term, priority, spec: assoc });
+            .push(Term::Constant(Cell::default(), Constant::Atom(atom, spec)));
+        self.stack.push(TokenDesc {
+            tt: TokenType::Term,
+            priority,
+            spec: assoc,
+        });
     }
 
-    fn shift(&mut self, token: Token, priority: usize, spec: Specifier)
+    fn shift(&mut self, token: Token, priority: usize, spec: Specifier) {
-    {
         let tt = match token {
-            Token::Constant(Constant::String(s))
+            Token::Constant(Constant::String(s)) if self.lexer.flags.double_quotes.is_codes() => {
-                if self.lexer.flags.double_quotes.is_codes() => {
+                let mut list = Term::Constant(Cell::default(), Constant::EmptyList);
-                    let mut list = Term::Constant(Cell::default(), Constant::EmptyList);
 
-                    for c in s.chars().rev() {
+                for c in s.chars().rev() {
-                        list = Term::Cons(
+                    list = Term::Cons(
+                        Cell::default(),
+                        Box::new(Term::Constant(
                             Cell::default(),
-                            Box::new(Term::Constant(
+                            Constant::Fixnum(c as isize),
-                                Cell::default(),
+                        )),
-                                Constant::Fixnum(c as isize),
+                        Box::new(list),
-                            )),
+                    );
-                            Box::new(list),
-                        );
-                    }
-
-                    self.terms.push(list);
-                    TokenType::Term
                 }
+
+                self.terms.push(list);
+                TokenType::Term
+            }
             Token::Constant(c) => {
                 self.terms.push(Term::Constant(Cell::default(), c));
                 TokenType::Term
-            },
+            }
             Token::Var(v) => {
                 if v.trim() == "_" {
                     self.terms.push(Term::AnonVar);
@@ -360,7 +360,7 @@ impl<'a, R: Read> Parser<'a, R> {
                 }
 
                 TokenType::Term
-            },
+            }
             Token::Comma => TokenType::Comma,
             Token::Open => TokenType::Open,
             Token::Close => TokenType::Close,
@@ -381,18 +381,13 @@ impl<'a, R: Read> Parser<'a, R> {
             if let Some(desc1) = self.stack.pop() {
                 if let Some(desc2) = self.stack.pop() {
                     if let Some(desc3) = self.stack.pop() {
-                        if is_xfx!(desc2.spec) && affirm_xfx(priority, desc2, desc3, desc1)
+                        if is_xfx!(desc2.spec) && affirm_xfx(priority, desc2, desc3, desc1) {
-                        {
                             self.push_binary_op(desc2, LTERM);
                             continue;
-                        }
+                        } else if is_yfx!(desc2.spec) && affirm_yfx(priority, desc2, desc3, desc1) {
-                        else if is_yfx!(desc2.spec) && affirm_yfx(priority, desc2, desc3, desc1)
-                        {
                             self.push_binary_op(desc2, LTERM);
                             continue;
-                        }
+                        } else if is_xfy!(desc2.spec) && affirm_xfy(priority, desc2, desc3, desc1) {
-                        else if is_xfy!(desc2.spec) && affirm_xfy(priority, desc2, desc3, desc1)
-                        {
                             self.push_binary_op(desc2, TERM);
                             continue;
                         } else {
@@ -425,12 +420,12 @@ impl<'a, R: Read> Parser<'a, R> {
         }
     }
 
-    fn compute_arity_in_brackets(&self) -> Option<usize>
+    fn compute_arity_in_brackets(&self) -> Option<usize> {
-    {
         let mut arity = 0;
 
         for (i, desc) in self.stack.iter().rev().enumerate() {
-            if i % 2 == 0 { // expect a term or non-comma operator.
+            if i % 2 == 0 {
+                // expect a term or non-comma operator.
                 if let TokenType::Comma = desc.tt {
                     return None;
                 } else if is_term!(desc.spec) || is_op!(desc.spec) || is_negate!(desc.spec) {
@@ -454,8 +449,7 @@ impl<'a, R: Read> Parser<'a, R> {
         None
     }
 
-    fn reduce_term(&mut self, op_dir: &CompositeOpDir) -> bool
+    fn reduce_term(&mut self, op_dir: &CompositeOpDir) -> bool {
-    {
         if self.stack.is_empty() {
             return false;
         }
@@ -464,7 +458,7 @@ impl<'a, R: Read> Parser<'a, R> {
 
         let arity = match self.compute_arity_in_brackets() {
             Some(arity) => arity,
-            None => return false
+            None => return false,
         };
 
         if self.stack.len() > 2 * arity {
@@ -490,9 +484,7 @@ impl<'a, R: Read> Parser<'a, R> {
             if self.atomize_term(&self.terms[idx - 1]).is_some() {
                 self.stack.truncate(stack_len + 1);
 
-                let mut subterms: Vec<_> = self.terms.drain(idx ..)
+                let mut subterms: Vec<_> = self.terms.drain(idx..).map(Box::new).collect();
-                    .map(|t| Box::new(t))
-                    .collect();
 
                 if let Some(name) = self.terms.pop().and_then(|t| self.atomize_term(&t)) {
                     // reduce the '.' functor to a cons cell if it applies.
@@ -503,11 +495,15 @@ impl<'a, R: Read> Parser<'a, R> {
                         self.terms.push(Term::Cons(Cell::default(), head, tail));
                     } else {
                         let spec = get_clause_spec(name.clone(), subterms.len(), op_dir);
-                        self.terms.push(Term::Clause(Cell::default(), name, subterms, spec));
+                        self.terms
+                            .push(Term::Clause(Cell::default(), name, subterms, spec));
                     }
 
-                    if let Some(&mut TokenDesc { ref mut priority, ref mut spec,
+                    if let Some(&mut TokenDesc {
-                                                 ref mut tt }) = self.stack.last_mut()
+                        ref mut priority,
+                        ref mut spec,
+                        ref mut tt,
+                    }) = self.stack.last_mut()
                     {
                         *tt = TokenType::Term;
                         *priority = 0;
@@ -523,7 +519,7 @@ impl<'a, R: Read> Parser<'a, R> {
     }
 
     pub fn devour_whitespace(&mut self) -> Result<(), ParserError> {
-	    self.lexer.scan_for_layout()?;
+        self.lexer.scan_for_layout()?;
         Ok(())
     }
 
@@ -531,8 +527,7 @@ impl<'a, R: Read> Parser<'a, R> {
         self.stack.clear()
     }
 
-    fn expand_comma_compacted_terms(&mut self, index: usize) -> usize
+    fn expand_comma_compacted_terms(&mut self, index: usize) -> usize {
-    {
         if let Some(term) = self.terms.pop() {
             let op_desc = self.stack[index - 1];
 
@@ -548,8 +543,7 @@ impl<'a, R: Read> Parser<'a, R> {
                         self.terms.extend(terms.into_iter());
                         return arity;
                     }
-                    _ => {
+                    _ => {}
-                    }
                 }
             }
 
@@ -559,12 +553,12 @@ impl<'a, R: Read> Parser<'a, R> {
         0
     }
 
-    fn compute_arity_in_list(&self) -> Option<usize>
+    fn compute_arity_in_list(&self) -> Option<usize> {
-    {
         let mut arity = 0;
 
         for (i, desc) in self.stack.iter().rev().enumerate() {
-            if i % 2 == 0 { // expect a term or non-comma operator.
+            if i % 2 == 0 {
+                // expect a term or non-comma operator.
                 if let TokenType::Comma = desc.tt {
                     return None;
                 } else if is_term!(desc.spec) || is_op!(desc.spec) {
@@ -590,8 +584,7 @@ impl<'a, R: Read> Parser<'a, R> {
         None
     }
 
-    fn reduce_list(&mut self) -> Result<bool, ParserError>
+    fn reduce_list(&mut self) -> Result<bool, ParserError> {
-    {
         if self.stack.is_empty() {
             return Ok(false);
         }
@@ -602,7 +595,8 @@ impl<'a, R: Read> Parser<'a, R> {
                 td.tt = TokenType::Term;
                 td.priority = 0;
 
-                self.terms.push(Term::Constant(Cell::default(), Constant::EmptyList));
+                self.terms
+                    .push(Term::Constant(Cell::default(), Constant::EmptyList));
                 return Ok(true);
             }
         }
@@ -611,7 +605,7 @@ impl<'a, R: Read> Parser<'a, R> {
 
         let mut arity = match self.compute_arity_in_list() {
             Some(arity) => arity,
-            None => return Ok(false)
+            None => return Ok(false),
         };
 
         // we know that self.stack.len() >= 2 by this point.
@@ -621,12 +615,15 @@ impl<'a, R: Read> Parser<'a, R> {
         let end_term = if self.stack[idx].tt != TokenType::HeadTailSeparator {
             Term::Constant(Cell::default(), Constant::EmptyList)
         } else {
-            let term =
+            let term = match self.terms.pop() {
-                match self.terms.pop() {
+                Some(term) => term,
-                    Some(term) => term,
+                _ => {
-                    _ => return Err(ParserError::IncompleteReduction(self.lexer.line_num,
+                    return Err(ParserError::IncompleteReduction(
-                                                                     self.lexer.col_num))
+                        self.lexer.line_num,
-                };
+                        self.lexer.col_num,
+                    ))
+                }
+            };
 
             if self.stack[idx].priority > 1000 {
                 arity += self.expand_comma_compacted_terms(idx);
@@ -639,15 +636,17 @@ impl<'a, R: Read> Parser<'a, R> {
 
         let idx = self.terms.len() - arity;
 
-        let list = self.terms.drain(idx ..)
+        let list = self.terms.drain(idx..).rev().fold(end_term, |acc, t| {
-            .rev()
+            Term::Cons(Cell::default(), Box::new(t), Box::new(acc))
-            .fold(end_term, |acc, t| Term::Cons(Cell::default(),
+        });
-                                                Box::new(t),
-                                                Box::new(acc)));
 
         self.stack.truncate(list_len);
 
-        self.stack.push(TokenDesc { tt: TokenType::Term, priority: 0, spec: TERM });
+        self.stack.push(TokenDesc {
+            tt: TokenType::Term,
+            priority: 0,
+            spec: TERM,
+        });
         self.terms.push(list);
 
         Ok(true)
@@ -664,8 +663,7 @@ impl<'a, R: Read> Parser<'a, R> {
                 td.priority = 0;
                 td.spec = TERM;
 
-                let term = Term::Constant(Cell::default(),
+                let term = Term::Constant(Cell::default(), atom!("{}", self.lexer.atom_tbl));
-                                          atom!("{}", self.lexer.atom_tbl));
                 self.terms.push(term);
                 return Ok(true);
             }
@@ -687,17 +685,19 @@ impl<'a, R: Read> Parser<'a, R> {
 
                         let term = match self.terms.pop() {
                             Some(term) => term,
-                            _ => return Err(ParserError::IncompleteReduction(
+                            _ => {
-                                self.lexer.line_num,
+                                return Err(ParserError::IncompleteReduction(
-                                self.lexer.col_num,
+                                    self.lexer.line_num,
-                            ))
+                                    self.lexer.col_num,
+                                ))
+                            }
                         };
 
                         self.terms.push(Term::Clause(
                             Cell::default(),
                             clause_name!("{}"),
                             vec![Box::new(term)],
-                            None
+                            None,
                         ));
 
                         return Ok(true);
@@ -722,35 +722,40 @@ impl<'a, R: Read> Parser<'a, R> {
 
         let idx = self.stack.len() - 2;
 
-        match self.stack.remove(idx) {
+        let td = self.stack.remove(idx);
-            td =>
+        match td.tt {
-                match td.tt {
+            TokenType::Open | TokenType::OpenCT => {
-                    TokenType::Open | TokenType::OpenCT => {
+                if self.stack[idx].tt == TokenType::Comma {
-                        if self.stack[idx].tt == TokenType::Comma {
+                    return false;
-                            return false;
-                        }
-
-                        if let Some(atom) = sep_to_atom(self.stack[idx].tt) {
-                            self.terms.push(Term::Constant(Cell::default(), Constant::Atom(atom, None)));
-                        }
-
-                        self.stack[idx].spec = TERM;
-                        self.stack[idx].tt = TokenType::Term;
-                        self.stack[idx].priority = 0;
-                        true
-                    },
-                    _ => false
                 }
+
+                if let Some(atom) = sep_to_atom(self.stack[idx].tt) {
+                    self.terms
+                        .push(Term::Constant(Cell::default(), Constant::Atom(atom, None)));
+                }
+
+                self.stack[idx].spec = TERM;
+                self.stack[idx].tt = TokenType::Term;
+                self.stack[idx].priority = 0;
+                true
+            }
+            _ => false,
         }
     }
 
     fn shift_op(&mut self, name: ClauseName, op_dir: &CompositeOpDir) -> Result<bool, ParserError> {
-        if let Some(OpDesc { pre, inf, post, spec }) = get_op_desc(name.clone(), op_dir) {
+        if let Some(OpDesc {
+            pre,
+            inf,
+            post,
+            spec,
+        }) = get_op_desc(name.clone(), op_dir)
+        {
             if (pre > 0 && inf + post > 0) || is_negate!(spec) {
                 match self.tokens.last().ok_or(ParserError::UnexpectedEOF)? {
                     // do this when layout hasn't been inserted,
                     // ie. why we don't match on Token::Open.
-                    &Token::OpenCT => {
+                    Token::OpenCT => {
                         // can't be prefix, so either inf == 0
                         // or post == 0.
                         self.reduce_op(inf + post);
@@ -764,7 +769,7 @@ impl<'a, R: Read> Parser<'a, R> {
                             spec & (XFX | XFY | YFX | YF | XF),
                             op_dir_val,
                         );
-                    },
+                    }
                     _ => {
                         self.reduce_op(inf + post);
 
@@ -782,11 +787,21 @@ impl<'a, R: Read> Parser<'a, R> {
                                 );
                             } else {
                                 let op_dir_val = op_dir.get(name.clone(), Fixity::Pre);
-                                self.promote_atom_op(name, pre, spec & (FX | FY | NEGATIVE_SIGN), op_dir_val);
+                                self.promote_atom_op(
+                                    name,
+                                    pre,
+                                    spec & (FX | FY | NEGATIVE_SIGN),
+                                    op_dir_val,
+                                );
                             }
                         } else {
                             let op_dir_val = op_dir.get(name.clone(), Fixity::Pre);
-                            self.promote_atom_op(name, pre, spec & (FX | FY | NEGATIVE_SIGN), op_dir_val);
+                            self.promote_atom_op(
+                                name,
+                                pre,
+                                spec & (FX | FY | NEGATIVE_SIGN),
+                                op_dir_val,
+                            );
                         }
                     }
                 }
@@ -807,49 +822,46 @@ impl<'a, R: Read> Parser<'a, R> {
             }
 
             Ok(true)
-        } else { // not an operator.
+        } else {
+            // not an operator.
             Ok(false)
         }
     }
 
     fn atomize_term(&self, term: &Term) -> Option<ClauseName> {
         match term {
-            &Term::Constant(_, ref c) => self.atomize_constant(c),
+            Term::Constant(_, ref c) => self.atomize_constant(c),
-            _ => None
+            _ => None,
         }
     }
 
     fn atomize_constant(&self, c: &Constant) -> Option<ClauseName> {
         match c {
-            &Constant::Atom(ref name, _) => Some(name.clone()),
+            Constant::Atom(ref name, _) => Some(name.clone()),
-            &Constant::Char(c) =>
+            Constant::Char(c) => Some(clause_name!(c.to_string(), self.lexer.atom_tbl)),
-                Some(clause_name!(c.to_string(), self.lexer.atom_tbl)),
+            Constant::EmptyList => Some(clause_name!(c.to_string(), self.lexer.atom_tbl)),
-            &Constant::EmptyList =>
+            _ => None,
-                Some(clause_name!(c.to_string(), self.lexer.atom_tbl)),
-            _ => None
         }
     }
 
-    fn negate_number<N, Negator, ToConstant>(
+    fn negate_number<N, Negator, ToConstant>(&mut self, n: N, negator: Negator, constr: ToConstant)
-        &mut self,
+    where
-        n: N,
+        Negator: Fn(N) -> N,
-        negator: Negator,
+        ToConstant: Fn(N) -> Constant,
-        constr: ToConstant
-    )
-    where Negator: Fn(N) -> N,
-          ToConstant: Fn(N) -> Constant
     {
         if let Some(desc) = self.stack.last().cloned() {
             if let Some(term) = self.terms.last().cloned() {
                 match term {
                     Term::Constant(_, Constant::Atom(ref name, _))
-                        if name.as_str() == "-" && (is_prefix!(desc.spec) || is_negate!(desc.spec)) => {
+                        if name.as_str() == "-"
-                            self.stack.pop();
+                            && (is_prefix!(desc.spec) || is_negate!(desc.spec)) =>
-                            self.terms.pop();
+                    {
+                        self.stack.pop();
+                        self.terms.pop();
 
-                            self.shift(Token::Constant(constr(negator(n))), 0, TERM);
+                        self.shift(Token::Constant(constr(negator(n))), 0, TERM);
-                            return;
+                        return;
-                        },
+                    }
                     _ => {}
                 }
             }
@@ -860,42 +872,37 @@ impl<'a, R: Read> Parser<'a, R> {
 
     fn shift_token(&mut self, token: Token, op_dir: &CompositeOpDir) -> Result<(), ParserError> {
         fn negate_rc<T: NegAssign>(mut t: Rc<T>) -> Rc<T> {
-            match Rc::get_mut(&mut t) {
+            if let Some(t) = Rc::get_mut(&mut t) {
-                Some(t) => {
+                t.neg_assign();
-                    t.neg_assign();
-                }
-                None => {
-                }
             };
 
             t
         }
 
         match token {
-            Token::Constant(Constant::Fixnum(n)) =>
+            Token::Constant(Constant::Fixnum(n)) => self.negate_number(n, |n| -n, Constant::Fixnum),
-                self.negate_number(n, |n| -n, Constant::Fixnum),
+            Token::Constant(Constant::Integer(n)) => {
-            Token::Constant(Constant::Integer(n)) =>
+                self.negate_number(n, negate_rc, Constant::Integer)
-                self.negate_number(n, negate_rc, Constant::Integer),
+            }
-            Token::Constant(Constant::Rational(n)) =>
+            Token::Constant(Constant::Rational(n)) => {
-                self.negate_number(n, negate_rc, Constant::Rational),
+                self.negate_number(n, negate_rc, Constant::Rational)
-            Token::Constant(Constant::Float(n)) =>
+            }
-                self.negate_number(
+            Token::Constant(Constant::Float(n)) => {
-                    n,
+                self.negate_number(n, |n| OrderedFloat(-n.into_inner()), Constant::Float)
-                    |n| OrderedFloat(-n.into_inner()),
+            }
-                    |n| Constant::Float(n)
+            Token::Constant(c) => {
-                ),
-            Token::Constant(c) =>
                 if let Some(name) = self.atomize_constant(&c) {
                     if !self.shift_op(name, op_dir)? {
                         self.shift(Token::Constant(c), 0, TERM);
                     }
                 } else {
                     self.shift(Token::Constant(c), 0, TERM);
-                },
+                }
+            }
             Token::Var(v) => self.shift(Token::Var(v), 0, TERM),
-            Token::Open   => self.shift(Token::Open, 1300, DELIMITER),
+            Token::Open => self.shift(Token::Open, 1300, DELIMITER),
             Token::OpenCT => self.shift(Token::OpenCT, 1300, DELIMITER),
-            Token::Close  =>
+            Token::Close => {
                 if !self.reduce_term(op_dir) {
                     if !self.reduce_brackets() {
                         return Err(ParserError::IncompleteReduction(
@@ -903,23 +910,26 @@ impl<'a, R: Read> Parser<'a, R> {
                             self.lexer.col_num,
                         ));
                     }
-                },
+                }
-            Token::OpenList  => self.shift(Token::OpenList, 1300, DELIMITER),
+            }
-            Token::CloseList =>
+            Token::OpenList => self.shift(Token::OpenList, 1300, DELIMITER),
+            Token::CloseList => {
                 if !self.reduce_list()? {
                     return Err(ParserError::IncompleteReduction(
                         self.lexer.line_num,
                         self.lexer.col_num,
                     ));
-                },
+                }
+            }
             Token::OpenCurly => self.shift(Token::OpenCurly, 1300, DELIMITER),
-            Token::CloseCurly =>
+            Token::CloseCurly => {
                 if !self.reduce_curly()? {
                     return Err(ParserError::IncompleteReduction(
                         self.lexer.line_num,
                         self.lexer.col_num,
                     ));
-                },
+                }
+            }
             Token::HeadTailSeparator => {
                 /* '|' as an operator must have priority > 1000 and can only be infix.
                  * See: http://www.complang.tuwien.ac.at/ulrich/iso-prolog/dtc2#Res_A78
@@ -930,23 +940,25 @@ impl<'a, R: Read> Parser<'a, R> {
 
                 self.reduce_op(priority);
                 self.shift(Token::HeadTailSeparator, priority, spec);
-            },
+            }
             Token::Comma => {
                 self.reduce_op(1000);
                 self.shift(Token::Comma, 1000, XFY);
-            },
+            }
-            Token::End =>
+            Token::End => match self.stack.last().map(|t| t.tt) {
-                match self.stack.last().map(|t| t.tt) {
+                Some(TokenType::Open)
-                    Some(TokenType::Open)
+                | Some(TokenType::OpenCT)
-                  | Some(TokenType::OpenCT)
+                | Some(TokenType::OpenList)
-                  | Some(TokenType::OpenList)
+                | Some(TokenType::OpenCurly)
-                  | Some(TokenType::OpenCurly)
+                | Some(TokenType::HeadTailSeparator)
-                  | Some(TokenType::HeadTailSeparator)
+                | Some(TokenType::Comma) => {
-                  | Some(TokenType::Comma)
+                    return Err(ParserError::IncompleteReduction(
-                      => return Err(ParserError::IncompleteReduction(self.lexer.line_num,
+                        self.lexer.line_num,
-                                                                     self.lexer.col_num)),
+                        self.lexer.col_num,
-                    _ => {}
+                    ))
                 }
+                _ => {}
+            },
         }
 
         Ok(())
@@ -957,8 +969,7 @@ impl<'a, R: Read> Parser<'a, R> {
         self.lexer.eof()
     }
 
-    pub fn read_term(&mut self, op_dir: &CompositeOpDir) -> Result<Term, ParserError>
+    pub fn read_term(&mut self, op_dir: &CompositeOpDir) -> Result<Term, ParserError> {
-    {
         self.tokens = read_tokens(&mut self.lexer)?;
 
         while let Some(token) = self.tokens.pop() {
@@ -968,21 +979,31 @@ impl<'a, R: Read> Parser<'a, R> {
         self.reduce_op(1400);
 
         if self.terms.len() > 1 || self.stack.len() > 1 {
-            return Err(ParserError::IncompleteReduction(self.lexer.line_num, self.lexer.col_num));
+            return Err(ParserError::IncompleteReduction(
+                self.lexer.line_num,
+                self.lexer.col_num,
+            ));
         }
 
         match self.terms.pop() {
-            Some(term) => if self.terms.is_empty() {
+            Some(term) => {
-                Ok(term)
+                if self.terms.is_empty() {
-            } else {
+                    Ok(term)
-                Err(ParserError::IncompleteReduction(self.lexer.line_num, self.lexer.col_num))
+                } else {
-            },
+                    Err(ParserError::IncompleteReduction(
-            _ => Err(ParserError::IncompleteReduction(self.lexer.line_num, self.lexer.col_num))
+                        self.lexer.line_num,
+                        self.lexer.col_num,
+                    ))
+                }
+            }
+            _ => Err(ParserError::IncompleteReduction(
+                self.lexer.line_num,
+                self.lexer.col_num,
+            )),
         }
     }
 
-    pub fn read(&mut self, op_dir: &CompositeOpDir) -> Result<Vec<Term>, ParserError>
+    pub fn read(&mut self, op_dir: &CompositeOpDir) -> Result<Vec<Term>, ParserError> {
-    {
         let mut terms = Vec::new();
 
         loop {

crates/prolog_parser/src/tabled_rc.rs

@@ -4,11 +4,11 @@ use std::collections::HashSet;
 use std::fmt;
 use std::hash::{Hash, Hasher};
 use std::ops::Deref;
-use std::rc::{Rc};
+use std::rc::Rc;
 
 pub struct TabledData<T> {
     table: Rc<RefCell<HashSet<Rc<T>>>>,
-    pub(crate) module_name: Rc<String>
+    pub(crate) module_name: Rc<String>,
 }
 
 impl<T: Hash + Eq + fmt::Debug> fmt::Debug for TabledData<T> {
@@ -22,14 +22,15 @@ impl<T: Hash + Eq + fmt::Debug> fmt::Debug for TabledData<T> {
 
 impl<T> Clone for TabledData<T> {
     fn clone(&self) -> Self {
-        TabledData { table: self.table.clone(),
+        TabledData {
-                     module_name: self.module_name.clone() }
+            table: self.table.clone(),
+            module_name: self.module_name.clone(),
+        }
     }
 }
 
 impl<T: PartialEq> PartialEq for TabledData<T> {
-    fn eq(&self, other: &TabledData<T>) -> bool
+    fn eq(&self, other: &TabledData<T>) -> bool {
-    {
         Rc::ptr_eq(&self.table, &other.table) && self.module_name == other.module_name
     }
 }
@@ -39,7 +40,7 @@ impl<T: Hash + Eq> TabledData<T> {
     pub fn new(module_name: Rc<String>) -> Self {
         TabledData {
             table: Rc::new(RefCell::new(HashSet::new())),
-            module_name
+            module_name,
         }
     }
 
@@ -51,7 +52,7 @@ impl<T: Hash + Eq> TabledData<T> {
 
 pub struct TabledRc<T: Hash + Eq> {
     pub(crate) atom: Rc<T>,
-    pub table: TabledData<T>
+    pub table: TabledData<T>,
 }
 
 impl<T: Hash + Eq + fmt::Debug> fmt::Debug for TabledRc<T> {
@@ -67,27 +68,27 @@ impl<T: Hash + Eq + fmt::Debug> fmt::Debug for TabledRc<T> {
 // from complaining when deriving Clone for StringList.
 impl<T: Hash + Eq> Clone for TabledRc<T> {
     fn clone(&self) -> Self {
-        TabledRc { atom: self.atom.clone(), table: self.table.clone() }
+        TabledRc {
+            atom: self.atom.clone(),
+            table: self.table.clone(),
+        }
     }
 }
 
 impl<T: Ord + Hash + Eq> PartialOrd for TabledRc<T> {
-    fn partial_cmp(&self, other: &Self) -> Option<Ordering>
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
-    {
         Some(self.atom.cmp(&other.atom))
     }
 }
 
 impl<T: Ord + Hash + Eq> Ord for TabledRc<T> {
-    fn cmp(&self, other: &Self) -> Ordering
+    fn cmp(&self, other: &Self) -> Ordering {
-    {
         self.atom.cmp(&other.atom)
     }
 }
 
 impl<T: Hash + Eq> PartialEq for TabledRc<T> {
-    fn eq(&self, other: &TabledRc<T>) -> bool
+    fn eq(&self, other: &TabledRc<T>) -> bool {
-    {
         self.atom == other.atom
     }
 }
@@ -103,8 +104,8 @@ impl<T: Hash + Eq> Hash for TabledRc<T> {
 impl<T: Hash + Eq + ToString> TabledRc<T> {
     pub fn new(atom: T, table: TabledData<T>) -> Self {
         let atom = match table.borrow_mut().take(&atom) {
-            Some(atom) => atom.clone(),
+            Some(atom) => atom,
-            None => Rc::new(atom)
+            None => Rc::new(atom),
         };
 
         table.borrow_mut().insert(atom.clone());
@@ -147,7 +148,7 @@ impl<T: Hash + Eq + fmt::Display> fmt::Display for TabledRc<T> {
 
 #[macro_export]
 macro_rules! tabled_rc {
-    ($e:expr, $tbl:expr) => (
+    ($e:expr, $tbl:expr) => {
-        TabledRc::new(String::from($e), $tbl.clone())
+        $crate::tabled_rc::TabledRc::new(String::from($e), $tbl.clone())
-    )
+    };
 }

crates/prolog_parser/tests/bom.rs

@@ -1,8 +1,6 @@
-extern crate prolog_parser_rebis;
+use prolog_parser::ast::*;
-
+use prolog_parser::lexer::{Lexer, Token};
-use prolog_parser_rebis::ast::*;
+use prolog_parser::tabled_rc::TabledData;
-use prolog_parser_rebis::lexer::{Lexer, Token};
-use prolog_parser_rebis::tabled_rc::TabledData;
 
 use std::rc::Rc;
 
@@ -27,7 +25,7 @@ fn skip_utf8_bom() {
     let mut lexer = Lexer::new(atom_tbl, flags, &mut stream);
     match lexer.next_token() {
         Ok(Token::Constant(Constant::Fixnum(4))) => (),
-        _ => assert!(false)
+        _ => assert!(false),
     }
 }
 
@@ -37,7 +35,6 @@ fn invalid_utf16_bom() {
     let stream = parsing_stream(bytes);
     match stream {
         Err(ParserError::Utf8Error(0, 0)) => (),
-        _ => assert!(false)
+        _ => assert!(false),
     }
 }
-

crates/prolog_parser/tests/parse_tokens.rs

@@ -1,8 +1,6 @@
-extern crate prolog_parser_rebis;
+use prolog_parser::ast::*;
-
+use prolog_parser::lexer::{Lexer, Token};
-use prolog_parser_rebis::ast::*;
+use prolog_parser::tabled_rc::TabledData;
-use prolog_parser_rebis::lexer::{Lexer, Token};
-use prolog_parser_rebis::tabled_rc::TabledData;
 
 use std::rc::Rc;
 

src/allocator.rs

@@ -1,4 +1,5 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
+use prolog_parser::temp_v;
 
 use crate::fixtures::*;
 use crate::forms::*;
@@ -14,8 +15,13 @@ pub trait Allocator<'a> {
     fn mark_anon_var<Target>(&mut self, _: Level, _: GenContext, _: &mut Vec<Target>)
     where
         Target: CompilationTarget<'a>;
-    fn mark_non_var<Target>(&mut self, _: Level, _: GenContext, _: &'a Cell<RegType>, _: &mut Vec<Target>)
+    fn mark_non_var<Target>(
-    where
+        &mut self,
+        _: Level,
+        _: GenContext,
+        _: &'a Cell<RegType>,
+        _: &mut Vec<Target>,
+    ) where
         Target: CompilationTarget<'a>;
     fn mark_reserved_var<Target>(
         &mut self,
@@ -28,8 +34,14 @@ pub trait Allocator<'a> {
         _: bool,
     ) where
         Target: CompilationTarget<'a>;
-    fn mark_var<Target>(&mut self, _: Rc<Var>, _: Level, _: &'a Cell<VarReg>, _: GenContext, _: &mut Vec<Target>)
+    fn mark_var<Target>(
-    where
+        &mut self,
+        _: Rc<Var>,
+        _: Level,
+        _: &'a Cell<VarReg>,
+        _: GenContext,
+        _: &mut Vec<Target>,
+    ) where
         Target: CompilationTarget<'a>;
 
     fn reset(&mut self);
@@ -47,7 +59,7 @@ pub trait Allocator<'a> {
     fn drain_var_data(
         &mut self,
         vs: VariableFixtures<'a>,
-        num_of_chunks: usize
+        num_of_chunks: usize,
     ) -> VariableFixtures<'a> {
         let mut perm_vs = VariableFixtures::new();
 

src/arithmetic.rs

@@ -1,4 +1,5 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
+use prolog_parser::{atom, clause_name};
 
 use crate::clause_types::*;
 use crate::fixtures::*;
@@ -10,9 +11,9 @@ use crate::machine::heap::*;
 use crate::machine::machine_errors::*;
 use crate::machine::machine_indices::*;
 
-use crate::ordered_float::*;
 use crate::rug::ops::PowAssign;
 use crate::rug::{Assign, Integer, Rational};
+use ordered_float::*;
 
 use std::cell::Cell;
 use std::cmp::{max, min, Ordering};
@@ -267,9 +268,7 @@ impl<'a> ArithmeticEvaluator<'a> {
 
     fn push_constant(&mut self, c: &Constant) -> Result<(), ArithmeticError> {
         match c {
-            &Constant::Fixnum(n) => self
+            &Constant::Fixnum(n) => self.interm.push(ArithmeticTerm::Number(Number::Fixnum(n))),
-                .interm
-                .push(ArithmeticTerm::Number(Number::Fixnum(n))),
             &Constant::Integer(ref n) => self
                 .interm
                 .push(ArithmeticTerm::Number(Number::Integer(n.clone()))),
@@ -326,17 +325,11 @@ impl<'a> ArithmeticEvaluator<'a> {
 // integer division rounding function -- 9.1.3.1.
 pub fn rnd_i<'a>(n: &'a Number) -> RefOrOwned<'a, Number> {
     match n {
-        &Number::Integer(_) => {
+        &Number::Integer(_) => RefOrOwned::Borrowed(n),
-            RefOrOwned::Borrowed(n)
+        &Number::Float(OrderedFloat(f)) => RefOrOwned::Owned(Number::from(
-        }
+            Integer::from_f64(f.floor()).unwrap_or_else(|| Integer::from(0)),
-        &Number::Float(OrderedFloat(f)) => {
+        )),
-            RefOrOwned::Owned(Number::from(
+        &Number::Fixnum(n) => RefOrOwned::Owned(Number::from(n)),
-                Integer::from_f64(f.floor()).unwrap_or_else(|| Integer::from(0))
-            ))
-        }
-        &Number::Fixnum(n) => {
-            RefOrOwned::Owned(Number::from(n))
-        }
         &Number::Rational(ref r) => {
             let r_ref = r.fract_floor_ref();
             let (mut fract, mut floor) = (Rational::new(), Integer::new());
@@ -432,31 +425,31 @@ impl Add<Number> for Number {
                     Number::from(Integer::from(n1) + Integer::from(n2))
                 })
             }
-            (Number::Fixnum(n1), Number::Integer(n2)) |
+            (Number::Fixnum(n1), Number::Integer(n2))
-            (Number::Integer(n2), Number::Fixnum(n1)) => {
+            | (Number::Integer(n2), Number::Fixnum(n1)) => {
                 Ok(Number::from(Integer::from(n1) + &*n2))
             }
-            (Number::Fixnum(n1), Number::Rational(n2)) |
+            (Number::Fixnum(n1), Number::Rational(n2))
-            (Number::Rational(n2), Number::Fixnum(n1)) => {
+            | (Number::Rational(n2), Number::Fixnum(n1)) => {
                 Ok(Number::from(Rational::from(n1) + &*n2))
             }
-            (Number::Fixnum(n1), Number::Float(OrderedFloat(n2))) |
+            (Number::Fixnum(n1), Number::Float(OrderedFloat(n2)))
-            (Number::Float(OrderedFloat(n2)), Number::Fixnum(n1)) => {
+            | (Number::Float(OrderedFloat(n2)), Number::Fixnum(n1)) => {
                 Ok(Number::Float(add_f(float_fn_to_f(n1)?, n2)?))
             }
             (Number::Integer(n1), Number::Integer(n2)) => {
                 Ok(Number::from(Integer::from(&*n1) + &*n2)) // add_i
             }
             (Number::Integer(n1), Number::Float(OrderedFloat(n2)))
-          | (Number::Float(OrderedFloat(n2)), Number::Integer(n1)) => {
+            | (Number::Float(OrderedFloat(n2)), Number::Integer(n1)) => {
                 Ok(Number::Float(add_f(float_i_to_f(&n1)?, n2)?))
             }
             (Number::Integer(n1), Number::Rational(n2))
-          | (Number::Rational(n2), Number::Integer(n1)) => {
+            | (Number::Rational(n2), Number::Integer(n1)) => {
                 Ok(Number::from(Rational::from(&*n1) + &*n2))
             }
             (Number::Rational(n1), Number::Float(OrderedFloat(n2)))
-          | (Number::Float(OrderedFloat(n2)), Number::Rational(n1)) => {
+            | (Number::Float(OrderedFloat(n2)), Number::Rational(n1)) => {
                 Ok(Number::Float(add_f(float_r_to_f(&n1)?, n2)?))
             }
             (Number::Float(OrderedFloat(f1)), Number::Float(OrderedFloat(f2))) => {
@@ -474,12 +467,13 @@ impl Neg for Number {
 
     fn neg(self) -> Self::Output {
         match self {
-            Number::Fixnum(n) =>
+            Number::Fixnum(n) => {
                 if let Some(n) = n.checked_neg() {
                     Number::Fixnum(n)
                 } else {
                     Number::from(-Integer::from(n))
                 }
+            }
             Number::Integer(n) => Number::Integer(Rc::new(-Integer::from(&*n))),
             Number::Float(OrderedFloat(f)) => Number::Float(OrderedFloat(-f)),
             Number::Rational(r) => Number::Rational(Rc::new(-Rational::from(&*r))),
@@ -507,16 +501,16 @@ impl Mul<Number> for Number {
                     Number::from(Integer::from(n1) * Integer::from(n2))
                 })
             }
-            (Number::Fixnum(n1), Number::Integer(n2)) |
+            (Number::Fixnum(n1), Number::Integer(n2))
-            (Number::Integer(n2), Number::Fixnum(n1)) => {
+            | (Number::Integer(n2), Number::Fixnum(n1)) => {
                 Ok(Number::from(Integer::from(n1) * &*n2))
             }
-            (Number::Fixnum(n1), Number::Rational(n2)) |
+            (Number::Fixnum(n1), Number::Rational(n2))
-            (Number::Rational(n2), Number::Fixnum(n1)) => {
+            | (Number::Rational(n2), Number::Fixnum(n1)) => {
                 Ok(Number::from(Rational::from(n1) * &*n2))
             }
-            (Number::Fixnum(n1), Number::Float(OrderedFloat(n2))) |
+            (Number::Fixnum(n1), Number::Float(OrderedFloat(n2)))
-            (Number::Float(OrderedFloat(n2)), Number::Fixnum(n1)) => {
+            | (Number::Float(OrderedFloat(n2)), Number::Fixnum(n1)) => {
                 Ok(Number::Float(mul_f(float_fn_to_f(n1)?, n2)?))
             }
             (Number::Integer(n1), Number::Integer(n2)) => {
@@ -549,72 +543,50 @@ impl Div<Number> for Number {
 
     fn div(self, rhs: Number) -> Self::Output {
         match (self, rhs) {
-            (Number::Fixnum(n1), Number::Fixnum(n2)) => {
+            (Number::Fixnum(n1), Number::Fixnum(n2)) => Ok(Number::Float(div_f(
-                Ok(Number::Float(div_f(
+                float_fn_to_f(n1)?,
-                    float_fn_to_f(n1)?,
+                float_fn_to_f(n2)?,
-                    float_fn_to_f(n2)?,
+            )?)),
-                )?))
+            (Number::Fixnum(n1), Number::Integer(n2)) => Ok(Number::Float(div_f(
-            }
+                float_fn_to_f(n1)?,
-            (Number::Fixnum(n1), Number::Integer(n2)) => {
+                float_i_to_f(&n2)?,
-                Ok(Number::Float(div_f(
+            )?)),
-                    float_fn_to_f(n1)?,
+            (Number::Integer(n1), Number::Fixnum(n2)) => Ok(Number::Float(div_f(
-                    float_i_to_f(&n2)?,
+                float_i_to_f(&n1)?,
-                )?))
+                float_fn_to_f(n2)?,
-            }
+            )?)),
-            (Number::Integer(n1), Number::Fixnum(n2)) => {
+            (Number::Fixnum(n1), Number::Rational(n2)) => Ok(Number::Float(div_f(
-                Ok(Number::Float(div_f(
+                float_fn_to_f(n1)?,
-                    float_i_to_f(&n1)?,
+                float_r_to_f(&n2)?,
-                    float_fn_to_f(n2)?,
+            )?)),
-                )?))
+            (Number::Rational(n1), Number::Fixnum(n2)) => Ok(Number::Float(div_f(
-            }
+                float_r_to_f(&n1)?,
-            (Number::Fixnum(n1), Number::Rational(n2)) => {
+                float_fn_to_f(n2)?,
-                Ok(Number::Float(div_f(
+            )?)),
-                    float_fn_to_f(n1)?,
-                    float_r_to_f(&n2)?,
-                )?))
-            }
-            (Number::Rational(n1), Number::Fixnum(n2)) => {
-                Ok(Number::Float(div_f(
-                    float_r_to_f(&n1)?,
-                    float_fn_to_f(n2)?,
-                )?))
-            }
             (Number::Fixnum(n1), Number::Float(OrderedFloat(n2))) => {
-                Ok(Number::Float(div_f(
+                Ok(Number::Float(div_f(float_fn_to_f(n1)?, n2)?))
-                    float_fn_to_f(n1)?,
-                    n2,
-                )?))
             }
             (Number::Float(OrderedFloat(n1)), Number::Fixnum(n2)) => {
-                Ok(Number::Float(div_f(
+                Ok(Number::Float(div_f(n1, float_fn_to_f(n2)?)?))
-                    n1,
-                    float_fn_to_f(n2)?,
-                )?))
-            }
-            (Number::Integer(n1), Number::Integer(n2)) => {
-                Ok(Number::Float(div_f(
-                    float_i_to_f(&n1)?,
-                    float_i_to_f(&n2)?,
-                )?))
             }
+            (Number::Integer(n1), Number::Integer(n2)) => Ok(Number::Float(div_f(
+                float_i_to_f(&n1)?,
+                float_i_to_f(&n2)?,
+            )?)),
             (Number::Integer(n1), Number::Float(OrderedFloat(n2))) => {
                 Ok(Number::Float(div_f(float_i_to_f(&n1)?, n2)?))
             }
             (Number::Float(OrderedFloat(n2)), Number::Integer(n1)) => {
                 Ok(Number::Float(div_f(n2, float_i_to_f(&n1)?)?))
             }
-            (Number::Integer(n1), Number::Rational(n2)) => {
+            (Number::Integer(n1), Number::Rational(n2)) => Ok(Number::Float(div_f(
-                Ok(Number::Float(div_f(
+                float_i_to_f(&n1)?,
-                    float_i_to_f(&n1)?,
+                float_r_to_f(&n2)?,
-                    float_r_to_f(&n2)?,
+            )?)),
-                )?))
+            (Number::Rational(n2), Number::Integer(n1)) => Ok(Number::Float(div_f(
-            }
+                float_r_to_f(&n2)?,
-            (Number::Rational(n2), Number::Integer(n1)) => {
+                float_i_to_f(&n1)?,
-                Ok(Number::Float(div_f(
+            )?)),
-                    float_r_to_f(&n2)?,
-                    float_i_to_f(&n1)?,
-                )?))
-            }
             (Number::Rational(n1), Number::Float(OrderedFloat(n2))) => {
                 Ok(Number::Float(div_f(float_r_to_f(&n1)?, n2)?))
             }
@@ -727,12 +699,8 @@ impl<'a> TryFrom<(Addr, &'a Heap)> for Number {
 
     fn try_from((addr, heap): (Addr, &'a Heap)) -> Result<Number, Self::Error> {
         match addr {
-            Addr::Fixnum(n) => {
+            Addr::Fixnum(n) => Ok(Number::from(n)),
-                Ok(Number::from(n))
+            Addr::Float(n) => Ok(Number::Float(n)),
-            }
-            Addr::Float(n) => {
-                Ok(Number::Float(n))
-            }
             Addr::Usize(n) => {
                 if let Ok(n) = isize::try_from(n) {
                     Ok(Number::from(n))
@@ -740,12 +708,8 @@ impl<'a> TryFrom<(Addr, &'a Heap)> for Number {
                     Ok(Number::from(Integer::from(n)))
                 }
             }
-            Addr::Con(h) => {
+            Addr::Con(h) => Number::try_from(&heap[h]),
-                Number::try_from(&heap[h])
+            _ => Err(()),
-            }
-            _ => {
-                Err(())
-            }
         }
     }
 }
@@ -755,35 +719,21 @@ impl<'a> TryFrom<&'a HeapCellValue> for Number {
 
     fn try_from(value: &'a HeapCellValue) -> Result<Number, Self::Error> {
         match value {
-            HeapCellValue::Addr(addr) => {
+            HeapCellValue::Addr(addr) => match addr {
-                match addr {
+                &Addr::Fixnum(n) => Ok(Number::from(n)),
-                    &Addr::Fixnum(n) => {
+                &Addr::Float(n) => Ok(Number::Float(n)),
+                &Addr::Usize(n) => {
+                    if let Ok(n) = isize::try_from(n) {
                         Ok(Number::from(n))
-                    }
+                    } else {
-                    &Addr::Float(n) => {
+                        Ok(Number::from(Integer::from(n)))
-                        Ok(Number::Float(n))
-                    }
-                    &Addr::Usize(n) => {
-                        if let Ok(n) = isize::try_from(n) {
-                            Ok(Number::from(n))
-                        } else {
-                            Ok(Number::from(Integer::from(n)))
-                        }
-                    }
-                    _ => {
-                        Err(())
                     }
                 }
-            }
+                _ => Err(()),
-            HeapCellValue::Integer(n) => {
+            },
-                Ok(Number::Integer(n.clone()))
+            HeapCellValue::Integer(n) => Ok(Number::Integer(n.clone())),
-            }
+            HeapCellValue::Rational(n) => Ok(Number::Rational(n.clone())),
-            HeapCellValue::Rational(n) => {
+            _ => Err(()),
-                Ok(Number::Rational(n.clone()))
-            }
-            _ => {
-                Err(())
-            }
         }
     }
 }

src/clause_types.rs

@@ -1,10 +1,11 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
+use prolog_parser::{clause_name, temp_v};
 
 use crate::forms::Number;
 use crate::machine::machine_indices::*;
 use crate::rug::rand::RandState;
 
-use crate::ref_thread_local::RefThreadLocal;
+use ref_thread_local::{ref_thread_local, RefThreadLocal};
 
 use std::collections::BTreeMap;
 
@@ -150,11 +151,6 @@ impl InlinedClauseType {
 
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub enum SystemClauseType {
-    // AbolishClause,
-    // AbolishModuleClause,
-    // AssertDynamicPredicateToBack,
-    // AssertDynamicPredicateToFront,
-    // AtEndOfExpansion,
     AtomChars,
     AtomCodes,
     AtomLength,
@@ -189,8 +185,6 @@ pub enum SystemClauseType {
     DynamicModuleResolution(usize),
     EnqueueAttributeGoal,
     EnqueueAttributedVar,
-//  ExpandGoal,
-//  ExpandTerm,
     FetchGlobalVar,
     FetchGlobalVarWithOffset,
     FirstStream,
@@ -207,16 +201,13 @@ pub enum SystemClauseType {
     GetAttrVarQueueDelimiter,
     GetAttrVarQueueBeyond,
     GetBValue,
-//  GetClause,
     GetContinuationChunk,
-//  GetModuleClause,
     GetNextDBRef,
     GetNextOpDBRef,
     IsPartialString,
     LookupDBRef,
     LookupOpDBRef,
     Halt,
-//  ModuleHeadIsDynamic,
     GetLiftedHeapFromOffset,
     GetLiftedHeapFromOffsetDiff,
     GetSCCCleaner,
@@ -225,10 +216,7 @@ pub enum SystemClauseType {
     InstallInferenceCounter,
     LiftedHeapLength,
     LoadLibraryAsStream,
-    // ModuleAssertDynamicPredicateToFront,
-    // ModuleAssertDynamicPredicateToBack,
     ModuleExists,
-    // ModuleRetractClause,
     NextEP,
     NoSuchPredicate,
     NumberToChars,
@@ -254,7 +242,6 @@ pub enum SystemClauseType {
     ResetContinuationMarker,
     ResetGlobalVarAtKey,
     ResetGlobalVarAtOffset,
-    // RetractClause,
     RestoreCutPolicy,
     SetCutPoint(RegType),
     SetInput,
@@ -324,11 +311,6 @@ pub enum SystemClauseType {
 impl SystemClauseType {
     pub fn name(&self) -> ClauseName {
         match self {
-            // &SystemClauseType::AbolishClause => clause_name!("$abolish_clause"),
-            // &SystemClauseType::AbolishModuleClause => clause_name!("$abolish_module_clause"),
-            // &SystemClauseType::AssertDynamicPredicateToBack => clause_name!("$assertz"),
-            // &SystemClauseType::AssertDynamicPredicateToFront => clause_name!("$asserta"),
-            // &SystemClauseType::AtEndOfExpansion => clause_name!("$at_end_of_expansion"),
             &SystemClauseType::AtomChars => clause_name!("$atom_chars"),
             &SystemClauseType::AtomCodes => clause_name!("$atom_codes"),
             &SystemClauseType::AtomLength => clause_name!("$atom_length"),
@@ -341,7 +323,9 @@ impl SystemClauseType {
             &SystemClauseType::ClearAttributeGoals => clause_name!("$clear_attribute_goals"),
             &SystemClauseType::CloneAttributeGoals => clause_name!("$clone_attribute_goals"),
             &SystemClauseType::CodesToNumber => clause_name!("$codes_to_number"),
-            &SystemClauseType::CopyTermWithoutAttrVars => clause_name!("$copy_term_without_attr_vars"),
+            &SystemClauseType::CopyTermWithoutAttrVars => {
+                clause_name!("$copy_term_without_attr_vars")
+            }
             &SystemClauseType::CreatePartialString => clause_name!("$create_partial_string"),
             &SystemClauseType::CurrentInput => clause_name!("$current_input"),
             &SystemClauseType::CurrentHostname => clause_name!("$current_hostname"),
@@ -356,52 +340,70 @@ impl SystemClauseType {
             &SystemClauseType::WorkingDirectory => clause_name!("$working_directory"),
             &SystemClauseType::PathCanonical => clause_name!("$path_canonical"),
             &SystemClauseType::FileTime => clause_name!("$file_time"),
-            &SystemClauseType::REPL(REPLCodePtr::AddDynamicPredicate) =>
+            &SystemClauseType::REPL(REPLCodePtr::AddDynamicPredicate) => {
-                clause_name!("$add_dynamic_predicate"),
+                clause_name!("$add_dynamic_predicate")
-            &SystemClauseType::REPL(REPLCodePtr::AddGoalExpansionClause) =>
+            }
-                clause_name!("$add_goal_expansion_clause"),
+            &SystemClauseType::REPL(REPLCodePtr::AddGoalExpansionClause) => {
-            &SystemClauseType::REPL(REPLCodePtr::AddTermExpansionClause) =>
+                clause_name!("$add_goal_expansion_clause")
-                clause_name!("$add_term_expansion_clause"),
+            }
-            &SystemClauseType::REPL(REPLCodePtr::ClauseToEvacuable) =>
+            &SystemClauseType::REPL(REPLCodePtr::AddTermExpansionClause) => {
-                clause_name!("$clause_to_evacuable"),
+                clause_name!("$add_term_expansion_clause")
-            &SystemClauseType::REPL(REPLCodePtr::ConcludeLoad) =>
+            }
-                clause_name!("$conclude_load"),
+            &SystemClauseType::REPL(REPLCodePtr::ClauseToEvacuable) => {
-            &SystemClauseType::REPL(REPLCodePtr::DeclareModule) =>
+                clause_name!("$clause_to_evacuable")
-                clause_name!("$declare_module"),
+            }
-            &SystemClauseType::REPL(REPLCodePtr::LoadCompiledLibrary) =>
+            &SystemClauseType::REPL(REPLCodePtr::ConcludeLoad) => clause_name!("$conclude_load"),
-                clause_name!("$load_compiled_library"),
+            &SystemClauseType::REPL(REPLCodePtr::DeclareModule) => clause_name!("$declare_module"),
-            &SystemClauseType::REPL(REPLCodePtr::PushLoadStatePayload) =>
+            &SystemClauseType::REPL(REPLCodePtr::LoadCompiledLibrary) => {
-                clause_name!("$push_load_state_payload"),
+                clause_name!("$load_compiled_library")
-            &SystemClauseType::REPL(REPLCodePtr::UserAsserta) =>
+            }
-                clause_name!("$asserta"),
+            &SystemClauseType::REPL(REPLCodePtr::PushLoadStatePayload) => {
-            &SystemClauseType::REPL(REPLCodePtr::UserAssertz) =>
+                clause_name!("$push_load_state_payload")
-                clause_name!("$assertz"),
+            }
-            &SystemClauseType::REPL(REPLCodePtr::UserRetract) =>
+            &SystemClauseType::REPL(REPLCodePtr::Asserta) => clause_name!("$asserta"),
-                clause_name!("$retract_clause"),
+            &SystemClauseType::REPL(REPLCodePtr::Assertz) => clause_name!("$assertz"),
-            &SystemClauseType::REPL(REPLCodePtr::UseModule) =>
+            &SystemClauseType::REPL(REPLCodePtr::Retract) => clause_name!("$retract_clause"),
-                clause_name!("$use_module"),
+            &SystemClauseType::REPL(REPLCodePtr::UseModule) => clause_name!("$use_module"),
-            &SystemClauseType::REPL(REPLCodePtr::PushLoadContext) =>
+            &SystemClauseType::REPL(REPLCodePtr::PushLoadContext) => {
-                clause_name!("$push_load_context"),
+                clause_name!("$push_load_context")
-            &SystemClauseType::REPL(REPLCodePtr::PopLoadContext) =>
+            }
-                clause_name!("$pop_load_context"),
+            &SystemClauseType::REPL(REPLCodePtr::PopLoadContext) => {
-            &SystemClauseType::REPL(REPLCodePtr::PopLoadStatePayload) =>
+                clause_name!("$pop_load_context")
-                clause_name!("$pop_load_state_payload"),
+            }
-            &SystemClauseType::REPL(REPLCodePtr::LoadContextSource) =>
+            &SystemClauseType::REPL(REPLCodePtr::PopLoadStatePayload) => {
-                clause_name!("$prolog_lc_source"),
+                clause_name!("$pop_load_state_payload")
-            &SystemClauseType::REPL(REPLCodePtr::LoadContextFile) =>
+            }
-                clause_name!("$prolog_lc_file"),
+            &SystemClauseType::REPL(REPLCodePtr::LoadContextSource) => {
-            &SystemClauseType::REPL(REPLCodePtr::LoadContextDirectory) =>
+                clause_name!("$prolog_lc_source")
-                clause_name!("$prolog_lc_dir"),
+            }
-            &SystemClauseType::REPL(REPLCodePtr::LoadContextModule) =>
+            &SystemClauseType::REPL(REPLCodePtr::LoadContextFile) => {
-                clause_name!("$prolog_lc_module"),
+                clause_name!("$prolog_lc_file")
-            &SystemClauseType::REPL(REPLCodePtr::LoadContextStream) =>
+            }
-                clause_name!("$prolog_lc_stream"),
+            &SystemClauseType::REPL(REPLCodePtr::LoadContextDirectory) => {
-            &SystemClauseType::REPL(REPLCodePtr::MetaPredicateProperty) =>
+                clause_name!("$prolog_lc_dir")
-                clause_name!("$cpp_meta_predicate_property"),
+            }
-            &SystemClauseType::REPL(REPLCodePtr::BuiltInProperty) =>
+            &SystemClauseType::REPL(REPLCodePtr::LoadContextModule) => {
-                clause_name!("$cpp_built_in_property"),
+                clause_name!("$prolog_lc_module")
-            &SystemClauseType::REPL(REPLCodePtr::CompilePendingPredicates) =>
+            }
-                clause_name!("$compile_pending_predicates"),
+            &SystemClauseType::REPL(REPLCodePtr::LoadContextStream) => {
+                clause_name!("$prolog_lc_stream")
+            }
+            &SystemClauseType::REPL(REPLCodePtr::MetaPredicateProperty) => {
+                clause_name!("$cpp_meta_predicate_property")
+            }
+            &SystemClauseType::REPL(REPLCodePtr::BuiltInProperty) => {
+                clause_name!("$cpp_built_in_property")
+            }
+            &SystemClauseType::REPL(REPLCodePtr::DynamicProperty) => {
+                clause_name!("$cpp_dynamic_property")
+            }
+            &SystemClauseType::REPL(REPLCodePtr::MultifileProperty) => {
+                clause_name!("$cpp_multifile_property")
+            }
+            &SystemClauseType::REPL(REPLCodePtr::DiscontiguousProperty) => {
+                clause_name!("$cpp_discontiguous_property")
+            }
+            &SystemClauseType::REPL(REPLCodePtr::AbolishClause) => clause_name!("$abolish_clause"),
             &SystemClauseType::Close => clause_name!("$close"),
             &SystemClauseType::CopyToLiftedHeap => clause_name!("$copy_to_lh"),
             &SystemClauseType::DeleteAttribute => clause_name!("$del_attr_non_head"),
@@ -410,8 +412,9 @@ impl SystemClauseType {
             &SystemClauseType::EnqueueAttributeGoal => clause_name!("$enqueue_attribute_goal"),
             &SystemClauseType::EnqueueAttributedVar => clause_name!("$enqueue_attr_var"),
             &SystemClauseType::FetchGlobalVar => clause_name!("$fetch_global_var"),
-            &SystemClauseType::FetchGlobalVarWithOffset =>
+            &SystemClauseType::FetchGlobalVarWithOffset => {
-                clause_name!("$fetch_global_var_with_offset"),
+                clause_name!("$fetch_global_var_with_offset")
+            }
             &SystemClauseType::FirstStream => clause_name!("$first_stream"),
             &SystemClauseType::FlushOutput => clause_name!("$flush_output"),
             &SystemClauseType::GetByte => clause_name!("$get_byte"),
@@ -437,13 +440,13 @@ impl SystemClauseType {
                 clause_name!("$get_lh_from_offset_diff")
             }
             &SystemClauseType::GetBValue => clause_name!("$get_b_value"),
-//          &SystemClauseType::GetClause => clause_name!("$get_clause"),
+            //          &SystemClauseType::GetClause => clause_name!("$get_clause"),
             &SystemClauseType::GetNextDBRef => clause_name!("$get_next_db_ref"),
             &SystemClauseType::GetNextOpDBRef => clause_name!("$get_next_op_db_ref"),
             &SystemClauseType::LookupDBRef => clause_name!("$lookup_db_ref"),
             &SystemClauseType::LookupOpDBRef => clause_name!("$lookup_op_db_ref"),
             &SystemClauseType::GetDoubleQuotes => clause_name!("$get_double_quotes"),
-//          &SystemClauseType::GetModuleClause => clause_name!("$get_module_clause"),
+            //          &SystemClauseType::GetModuleClause => clause_name!("$get_module_clause"),
             &SystemClauseType::GetSCCCleaner => clause_name!("$get_scc_cleaner"),
             &SystemClauseType::Halt => clause_name!("$halt"),
             &SystemClauseType::HeadIsDynamic => clause_name!("$head_is_dynamic"),
@@ -468,7 +471,7 @@ impl SystemClauseType {
             // &SystemClauseType::ModuleAssertDynamicPredicateToBack => {
             //     clause_name!("$module_assertz")
             // }
-//          &SystemClauseType::ModuleHeadIsDynamic => clause_name!("$module_head_is_dynamic"),
+            //          &SystemClauseType::ModuleHeadIsDynamic => clause_name!("$module_head_is_dynamic"),
             &SystemClauseType::ModuleExists => clause_name!("$module_exists"),
             &SystemClauseType::NextStream => clause_name!("$next_stream"),
             &SystemClauseType::NoSuchPredicate => clause_name!("$no_such_predicate"),
@@ -520,7 +523,9 @@ impl SystemClauseType {
             &SystemClauseType::ReadTerm => clause_name!("$read_term"),
             &SystemClauseType::ReadTermFromChars => clause_name!("$read_term_from_chars"),
             &SystemClauseType::ResetGlobalVarAtKey => clause_name!("$reset_global_var_at_key"),
-            &SystemClauseType::ResetGlobalVarAtOffset => clause_name!("$reset_global_var_at_offset"),
+            &SystemClauseType::ResetGlobalVarAtOffset => {
+                clause_name!("$reset_global_var_at_offset")
+            }
             &SystemClauseType::ResetBlock => clause_name!("$reset_block"),
             &SystemClauseType::ResetContinuationMarker => clause_name!("$reset_cont_marker"),
             &SystemClauseType::ReturnFromVerifyAttr => clause_name!("$return_from_verify_attr"),
@@ -534,7 +539,9 @@ impl SystemClauseType {
             &SystemClauseType::SocketServerAccept => clause_name!("$socket_server_accept"),
             &SystemClauseType::SocketServerClose => clause_name!("$socket_server_close"),
             &SystemClauseType::Succeed => clause_name!("$succeed"),
-            &SystemClauseType::TermAttributedVariables => clause_name!("$term_attributed_variables"),
+            &SystemClauseType::TermAttributedVariables => {
+                clause_name!("$term_attributed_variables")
+            }
             &SystemClauseType::TermVariables => clause_name!("$term_variables"),
             &SystemClauseType::TruncateLiftedHeapTo => clause_name!("$truncate_lh_to"),
             &SystemClauseType::UnifyWithOccursCheck => clause_name!("$unify_with_occurs_check"),
@@ -555,7 +562,9 @@ impl SystemClauseType {
             &SystemClauseType::Ed25519Sign => clause_name!("$ed25519_sign"),
             &SystemClauseType::Ed25519Verify => clause_name!("$ed25519_verify"),
             &SystemClauseType::Ed25519NewKeyPair => clause_name!("$ed25519_new_keypair"),
-            &SystemClauseType::Ed25519KeyPairPublicKey => clause_name!("$ed25519_keypair_public_key"),
+            &SystemClauseType::Ed25519KeyPairPublicKey => {
+                clause_name!("$ed25519_keypair_public_key")
+            }
             &SystemClauseType::Curve25519ScalarMult => clause_name!("$curve25519_scalar_mult"),
             &SystemClauseType::LoadHTML => clause_name!("$load_html"),
             &SystemClauseType::LoadXML => clause_name!("$load_xml"),
@@ -569,21 +578,21 @@ impl SystemClauseType {
 
     pub fn from(name: &str, arity: usize) -> Option<SystemClauseType> {
         match (name, arity) {
-            // ("$abolish_clause", 2) => Some(SystemClauseType::AbolishClause),
+            ("$abolish_clause", 3) => Some(SystemClauseType::REPL(REPLCodePtr::AbolishClause)),
-            ("$add_dynamic_predicate", 3) =>
+            ("$add_dynamic_predicate", 3) => {
-                Some(SystemClauseType::REPL(REPLCodePtr::AddDynamicPredicate)),
+                Some(SystemClauseType::REPL(REPLCodePtr::AddDynamicPredicate))
-            ("$add_goal_expansion_clause", 4) =>
+            }
-                Some(SystemClauseType::REPL(REPLCodePtr::AddGoalExpansionClause)),
+            ("$add_goal_expansion_clause", 4) => {
-            ("$add_term_expansion_clause", 3) =>
+                Some(SystemClauseType::REPL(REPLCodePtr::AddGoalExpansionClause))
-                Some(SystemClauseType::REPL(REPLCodePtr::AddTermExpansionClause)),
+            }
-            // ("$at_end_of_expansion", 0) => Some(SystemClauseType::AtEndOfExpansion),
+            ("$add_term_expansion_clause", 3) => {
+                Some(SystemClauseType::REPL(REPLCodePtr::AddTermExpansionClause))
+            }
             ("$atom_chars", 2) => Some(SystemClauseType::AtomChars),
             ("$atom_codes", 2) => Some(SystemClauseType::AtomCodes),
             ("$atom_length", 2) => Some(SystemClauseType::AtomLength),
             // ("$abolish_module_clause", 3) => Some(SystemClauseType::AbolishModuleClause),
             ("$bind_from_register", 2) => Some(SystemClauseType::BindFromRegister),
-            // ("$module_asserta", 5) => Some(SystemClauseType::ModuleAssertDynamicPredicateToFront),
-            // ("$module_assertz", 5) => Some(SystemClauseType::ModuleAssertDynamicPredicateToBack),
             ("$call_continuation", 1) => Some(SystemClauseType::CallContinuation),
             ("$char_code", 2) => Some(SystemClauseType::CharCode),
             ("$char_type", 2) => Some(SystemClauseType::CharType),
@@ -616,10 +625,10 @@ impl SystemClauseType {
             ("$peek_char", 2) => Some(SystemClauseType::PeekChar),
             ("$peek_code", 2) => Some(SystemClauseType::PeekCode),
             ("$is_partial_string", 1) => Some(SystemClauseType::IsPartialString),
-//          ("$expand_term", 2) => Some(SystemClauseType::ExpandTerm),
-//          ("$expand_goal", 2) => Some(SystemClauseType::ExpandGoal),
             ("$fetch_global_var", 2) => Some(SystemClauseType::FetchGlobalVar),
-            ("$fetch_global_var_with_offset", 3) => Some(SystemClauseType::FetchGlobalVarWithOffset),
+            ("$fetch_global_var_with_offset", 3) => {
+                Some(SystemClauseType::FetchGlobalVarWithOffset)
+            }
             ("$get_byte", 2) => Some(SystemClauseType::GetByte),
             ("$get_char", 2) => Some(SystemClauseType::GetChar),
             ("$get_n_chars", 3) => Some(SystemClauseType::GetNChars),
@@ -628,18 +637,10 @@ impl SystemClauseType {
             ("$points_to_cont_reset_marker", 1) => {
                 Some(SystemClauseType::PointsToContinuationResetMarker)
             }
-            ("$put_byte", 2) => {
+            ("$put_byte", 2) => Some(SystemClauseType::PutByte),
-                Some(SystemClauseType::PutByte)
+            ("$put_char", 2) => Some(SystemClauseType::PutChar),
-            }
+            ("$put_chars", 2) => Some(SystemClauseType::PutChars),
-            ("$put_char", 2) => {
+            ("$put_code", 2) => Some(SystemClauseType::PutCode),
-                Some(SystemClauseType::PutChar)
-            }
-            ("$put_chars", 2) => {
-                Some(SystemClauseType::PutChars)
-            }
-            ("$put_code", 2) => {
-                Some(SystemClauseType::PutCode)
-            }
             ("$reset_attr_var_state", 0) => Some(SystemClauseType::ResetAttrVarState),
             ("$truncate_if_no_lh_growth", 1) => {
                 Some(SystemClauseType::TruncateIfNoLiftedHeapGrowth)
@@ -649,8 +650,6 @@ impl SystemClauseType {
             }
             ("$get_attr_list", 2) => Some(SystemClauseType::GetAttributedVariableList),
             ("$get_b_value", 1) => Some(SystemClauseType::GetBValue),
-//          ("$get_clause", 2) => Some(SystemClauseType::GetClause),
-//          ("$get_module_clause", 3) => Some(SystemClauseType::GetModuleClause),
             ("$get_lh_from_offset", 2) => Some(SystemClauseType::GetLiftedHeapFromOffset),
             ("$get_lh_from_offset_diff", 3) => Some(SystemClauseType::GetLiftedHeapFromOffsetDiff),
             ("$get_double_quotes", 1) => Some(SystemClauseType::GetDoubleQuotes),
@@ -664,8 +663,6 @@ impl SystemClauseType {
             ("$cpu_now", 1) => Some(SystemClauseType::CpuNow),
             ("$current_time", 1) => Some(SystemClauseType::CurrentTime),
             ("$module_exists", 1) => Some(SystemClauseType::ModuleExists),
-            // ("$module_retract_clause", 5) => Some(SystemClauseType::ModuleRetractClause),
-            // ("$module_head_is_dynamic", 2) => Some(SystemClauseType::ModuleHeadIsDynamic),
             ("$no_such_predicate", 2) => Some(SystemClauseType::NoSuchPredicate),
             ("$number_to_chars", 2) => Some(SystemClauseType::NumberToChars),
             ("$number_to_codes", 2) => Some(SystemClauseType::NumberToCodes),
@@ -700,7 +697,6 @@ impl SystemClauseType {
             ("$reset_cont_marker", 0) => Some(SystemClauseType::ResetContinuationMarker),
             ("$reset_global_var_at_key", 1) => Some(SystemClauseType::ResetGlobalVarAtKey),
             ("$reset_global_var_at_offset", 3) => Some(SystemClauseType::ResetGlobalVarAtOffset),
-            // ("$retract_clause", 4) => Some(SystemClauseType::RetractClause),
             ("$return_from_verify_attr", 0) => Some(SystemClauseType::ReturnFromVerifyAttr),
             ("$set_ball", 1) => Some(SystemClauseType::SetBall),
             ("$set_cp_by_default", 1) => Some(SystemClauseType::SetCutPointByDefault(temp_v!(1))),
@@ -713,7 +709,9 @@ impl SystemClauseType {
             ("$socket_server_accept", 7) => Some(SystemClauseType::SocketServerAccept),
             ("$socket_server_close", 1) => Some(SystemClauseType::SocketServerClose),
             ("$store_global_var", 2) => Some(SystemClauseType::StoreGlobalVar),
-            ("$store_global_var_with_offset", 2) => Some(SystemClauseType::StoreGlobalVarWithOffset),
+            ("$store_global_var_with_offset", 2) => {
+                Some(SystemClauseType::StoreGlobalVarWithOffset)
+            }
             ("$term_attributed_variables", 2) => Some(SystemClauseType::TermAttributedVariables),
             ("$term_variables", 2) => Some(SystemClauseType::TermVariables),
             ("$truncate_lh_to", 1) => Some(SystemClauseType::TruncateLiftedHeapTo),
@@ -730,15 +728,21 @@ impl SystemClauseType {
             ("$working_directory", 2) => Some(SystemClauseType::WorkingDirectory),
             ("$path_canonical", 2) => Some(SystemClauseType::PathCanonical),
             ("$file_time", 3) => Some(SystemClauseType::FileTime),
-            ("$clause_to_evacuable", 3) => Some(SystemClauseType::REPL(REPLCodePtr::ClauseToEvacuable)),
+            ("$clause_to_evacuable", 3) => {
+                Some(SystemClauseType::REPL(REPLCodePtr::ClauseToEvacuable))
+            }
             ("$conclude_load", 1) => Some(SystemClauseType::REPL(REPLCodePtr::ConcludeLoad)),
             ("$use_module", 3) => Some(SystemClauseType::REPL(REPLCodePtr::UseModule)),
             ("$declare_module", 3) => Some(SystemClauseType::REPL(REPLCodePtr::DeclareModule)),
-            ("$load_compiled_library", 2) => Some(SystemClauseType::REPL(REPLCodePtr::LoadCompiledLibrary)),
+            ("$load_compiled_library", 2) => {
-            ("$push_load_state_payload", 1) => Some(SystemClauseType::REPL(REPLCodePtr::PushLoadStatePayload)),
+                Some(SystemClauseType::REPL(REPLCodePtr::LoadCompiledLibrary))
-            ("$asserta", 4) => Some(SystemClauseType::REPL(REPLCodePtr::UserAsserta)),
+            }
-            ("$assertz", 4) => Some(SystemClauseType::REPL(REPLCodePtr::UserAssertz)),
+            ("$push_load_state_payload", 1) => {
-            ("$retract_clause", 3) => Some(SystemClauseType::REPL(REPLCodePtr::UserRetract)),
+                Some(SystemClauseType::REPL(REPLCodePtr::PushLoadStatePayload))
+            }
+            ("$asserta", 5) => Some(SystemClauseType::REPL(REPLCodePtr::Asserta)),
+            ("$assertz", 5) => Some(SystemClauseType::REPL(REPLCodePtr::Assertz)),
+            ("$retract_clause", 4) => Some(SystemClauseType::REPL(REPLCodePtr::Retract)),
             ("$variant", 2) => Some(SystemClauseType::Variant),
             ("$wam_instructions", 4) => Some(SystemClauseType::WAMInstructions),
             ("$write_term", 7) => Some(SystemClauseType::WriteTerm),
@@ -764,16 +768,38 @@ impl SystemClauseType {
             ("$chars_base64", 4) => Some(SystemClauseType::CharsBase64),
             ("$load_library_as_stream", 3) => Some(SystemClauseType::LoadLibraryAsStream),
             ("$push_load_context", 2) => Some(SystemClauseType::REPL(REPLCodePtr::PushLoadContext)),
-            ("$pop_load_state_payload", 1) => Some(SystemClauseType::REPL(REPLCodePtr::PopLoadStatePayload)),
+            ("$pop_load_state_payload", 1) => {
+                Some(SystemClauseType::REPL(REPLCodePtr::PopLoadStatePayload))
+            }
             ("$pop_load_context", 0) => Some(SystemClauseType::REPL(REPLCodePtr::PopLoadContext)),
-            ("$prolog_lc_source", 1) => Some(SystemClauseType::REPL(REPLCodePtr::LoadContextSource)),
+            ("$prolog_lc_source", 1) => {
+                Some(SystemClauseType::REPL(REPLCodePtr::LoadContextSource))
+            }
             ("$prolog_lc_file", 1) => Some(SystemClauseType::REPL(REPLCodePtr::LoadContextFile)),
-            ("$prolog_lc_dir", 1) => Some(SystemClauseType::REPL(REPLCodePtr::LoadContextDirectory)),
+            ("$prolog_lc_dir", 1) => {
-            ("$prolog_lc_module", 1) => Some(SystemClauseType::REPL(REPLCodePtr::LoadContextModule)),
+                Some(SystemClauseType::REPL(REPLCodePtr::LoadContextDirectory))
-            ("$prolog_lc_stream", 1) => Some(SystemClauseType::REPL(REPLCodePtr::LoadContextStream)),
+            }
-            ("$cpp_meta_predicate_property", 4) => Some(SystemClauseType::REPL(REPLCodePtr::MetaPredicateProperty)),
+            ("$prolog_lc_module", 1) => {
-            ("$cpp_built_in_property", 2) => Some(SystemClauseType::REPL(REPLCodePtr::BuiltInProperty)),
+                Some(SystemClauseType::REPL(REPLCodePtr::LoadContextModule))
-            ("$compile_pending_predicates", 1) => Some(SystemClauseType::REPL(REPLCodePtr::CompilePendingPredicates)),
+            }
+            ("$prolog_lc_stream", 1) => {
+                Some(SystemClauseType::REPL(REPLCodePtr::LoadContextStream))
+            }
+            ("$cpp_meta_predicate_property", 4) => {
+                Some(SystemClauseType::REPL(REPLCodePtr::MetaPredicateProperty))
+            }
+            ("$cpp_built_in_property", 2) => {
+                Some(SystemClauseType::REPL(REPLCodePtr::BuiltInProperty))
+            }
+            ("$cpp_dynamic_property", 3) => {
+                Some(SystemClauseType::REPL(REPLCodePtr::DynamicProperty))
+            }
+            ("$cpp_multifile_property", 3) => {
+                Some(SystemClauseType::REPL(REPLCodePtr::MultifileProperty))
+            }
+            ("$cpp_discontiguous_property", 3) => {
+                Some(SystemClauseType::REPL(REPLCodePtr::DiscontiguousProperty))
+            }
             _ => None,
         }
     }
@@ -852,10 +878,10 @@ impl ClauseType {
         match self {
             &ClauseType::Op(_, ref spec, _) => Some(spec.clone()),
             &ClauseType::Inlined(InlinedClauseType::CompareNumber(..))
-          | &ClauseType::BuiltIn(BuiltInClauseType::Is(..))
+            | &ClauseType::BuiltIn(BuiltInClauseType::Is(..))
-          | &ClauseType::BuiltIn(BuiltInClauseType::CompareTerm(_))
+            | &ClauseType::BuiltIn(BuiltInClauseType::CompareTerm(_))
-          | &ClauseType::BuiltIn(BuiltInClauseType::NotEq)
+            | &ClauseType::BuiltIn(BuiltInClauseType::NotEq)
-          | &ClauseType::BuiltIn(BuiltInClauseType::Eq) => Some(SharedOpDesc::new(700, XFX)),
+            | &ClauseType::BuiltIn(BuiltInClauseType::Eq) => Some(SharedOpDesc::new(700, XFX)),
             _ => None,
         }
     }
@@ -863,7 +889,7 @@ impl ClauseType {
     pub fn name(&self) -> ClauseName {
         match self {
             &ClauseType::BuiltIn(ref built_in) => built_in.name(),
-            &ClauseType::CallN => clause_name!("call"),
+            &ClauseType::CallN => clause_name!("$call"),
             &ClauseType::Inlined(ref inlined) => clause_name!(inlined.name()),
             &ClauseType::Op(ref name, ..) => name.clone(),
             &ClauseType::Named(ref name, ..) => name.clone(),
@@ -882,7 +908,7 @@ impl ClauseType {
                     .unwrap_or_else(|| {
                         if let Some(spec) = spec {
                             ClauseType::Op(name, spec, CodeIndex::default())
-                        } else if name.as_str() == "call" {
+                        } else if name.as_str() == "$call" {
                             ClauseType::CallN
                         } else {
                             ClauseType::Named(name, arity, CodeIndex::default())

src/codegen.rs

@@ -1,6 +1,7 @@
 /// Code generation to WAM-like instructions.
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
-use crate::prolog_parser_rebis::tabled_rc::TabledData;
+use prolog_parser::tabled_rc::TabledData;
+use prolog_parser::{perm_v, temp_v};
 
 use crate::allocator::*;
 use crate::arithmetic::*;
@@ -14,7 +15,7 @@ use crate::targets::*;
 
 use crate::machine::machine_errors::*;
 
-use crate::indexmap::{IndexMap, IndexSet};
+use indexmap::{IndexMap, IndexSet};
 
 use std::cell::Cell;
 use std::collections::VecDeque;
@@ -66,18 +67,14 @@ impl<'a> ConjunctInfo<'a> {
         self.has_deep_cut as usize
     }
 
-    fn mark_unsafe_vars(
+    fn mark_unsafe_vars(&self, mut unsafe_var_marker: UnsafeVarMarker, code: &mut Code) {
-        &self,
-        mut unsafe_var_marker: UnsafeVarMarker,
-        code: &mut Code,
-    ) {
         if code.is_empty() {
             return;
         }
 
         let mut code_index = 0;
 
-        for phase in 0 .. {
+        for phase in 0.. {
             while let Line::Query(ref query_instr) = &code[code_index] {
                 if !unsafe_var_marker.mark_safe_vars(query_instr) {
                     unsafe_var_marker.mark_phase(query_instr, phase);
@@ -95,7 +92,7 @@ impl<'a> ConjunctInfo<'a> {
 
         code_index = 0;
 
-        for phase in 0 .. {
+        for phase in 0.. {
             while let Line::Query(ref mut query_instr) = &mut code[code_index] {
                 unsafe_var_marker.mark_unsafe_vars(query_instr, phase);
                 code_index += 1;
@@ -173,7 +170,8 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
         code: &mut Code,
     ) -> RegType {
         let mut target = Vec::new();
-        self.marker.mark_var(name, Level::Shallow, vr, term_loc, &mut target);
+        self.marker
+            .mark_var(name, Level::Shallow, vr, term_loc, &mut target);
 
         if !target.is_empty() {
             code.extend(target.into_iter().map(Line::Query));
@@ -191,9 +189,7 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
         code: &mut Code,
     ) -> RegType {
         match self.marker.bindings().get(&name) {
-            Some(&VarData::Temp(_, t, _)) if t != 0 => {
+            Some(&VarData::Temp(_, t, _)) if t != 0 => RegType::Temp(t),
-                RegType::Temp(t)
-            }
             Some(&VarData::Perm(p)) if p != 0 => {
                 if let GenContext::Last(_) = term_loc {
                     self.mark_var_in_non_callable(name.clone(), term_loc, vr, code);
@@ -202,9 +198,7 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
                     RegType::Perm(p)
                 }
             }
-            _ => {
+            _ => self.mark_var_in_non_callable(name, term_loc, vr, code),
-                self.mark_var_in_non_callable(name, term_loc, vr, code)
-            }
         }
     }
 
@@ -231,7 +225,8 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
         target: &mut Vec<Target>,
     ) {
         if is_exposed || self.get_var_count(var.as_ref()) > 1 {
-            self.marker.mark_var(var.clone(), Level::Deep, cell, term_loc, target);
+            self.marker
+                .mark_var(var.clone(), Level::Deep, cell, term_loc, target);
         } else {
             Self::add_or_increment_void_instr(target);
         }
@@ -252,7 +247,8 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
                 Self::add_or_increment_void_instr(target);
             }
             &Term::Cons(ref cell, _, _) | &Term::Clause(ref cell, _, _, _) => {
-                self.marker.mark_non_var(Level::Deep, term_loc, cell, target);
+                self.marker
+                    .mark_non_var(Level::Deep, term_loc, cell, target);
                 target.push(Target::clause_arg_to_instr(cell.get()));
             }
             &Term::Constant(_, ref constant) => {
@@ -264,7 +260,7 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
         };
     }
 
-     fn compile_target<Target, Iter>(
+    fn compile_target<Target, Iter>(
         &mut self,
         iter: Iter,
         term_loc: GenContext,
@@ -334,13 +330,14 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
                         }
                     }
 
-                    self.marker.mark_var(var.clone(), lvl, cell, term_loc, &mut target);
+                    self.marker
+                        .mark_var(var.clone(), lvl, cell, term_loc, &mut target);
                 }
                 TermRef::Var(lvl @ Level::Shallow, cell, var) => {
-                    self.marker.mark_var(var.clone(), lvl, cell, term_loc, &mut target);
+                    self.marker
-                }
+                        .mark_var(var.clone(), lvl, cell, term_loc, &mut target);
-                _ => {
                 }
+                _ => {}
             };
         }
 
@@ -353,8 +350,7 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
         while let Some((chunk_num, lt_arity, chunked_terms)) = iter.next() {
             for (i, chunked_term) in chunked_terms.iter().enumerate() {
                 let term_loc = match chunked_term {
-                    &ChunkedTerm::HeadClause(..) =>
+                    &ChunkedTerm::HeadClause(..) => GenContext::Head,
-                        GenContext::Head,
                     &ChunkedTerm::BodyTerm(_) => {
                         if i < chunked_terms.len() - 1 {
                             GenContext::Mid(chunk_num)
@@ -391,8 +387,7 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
             &QueryTerm::Clause(_, ref ct, ref terms, false) => {
                 code.push(call_clause!(ct.clone(), terms.len(), pvs));
             }
-            _ => {
+            _ => {}
-            }
         }
     }
 
@@ -407,8 +402,7 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
                 &mut ControlInstruction::JmpBy(_, _, _, ref mut last_call) => {
                     *last_call = true;
                 }
-                &mut ControlInstruction::Proceed => {
+                &mut ControlInstruction::Proceed => {}
-                }
                 _ => {
                     dealloc_index += 1;
                 }
@@ -416,8 +410,7 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
             Some(&mut Line::Cut(CutInstruction::Cut(_))) => {
                 dealloc_index += 1;
             }
-            _ => {
+            _ => {}
-            }
         };
 
         dealloc_index
@@ -437,23 +430,17 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
                 let (mut lcode, at_1) = self.call_arith_eval(terms[0].as_ref(), 1)?;
                 let (mut rcode, at_2) = self.call_arith_eval(terms[1].as_ref(), 2)?;
 
-                let at_1 =
+                let at_1 = if let &Term::Var(ref vr, ref name) = terms[0].as_ref() {
-                    if let &Term::Var(ref vr, ref name) = terms[0].as_ref() {
+                    ArithmeticTerm::Reg(self.mark_non_callable(name.clone(), 1, term_loc, vr, code))
-                        ArithmeticTerm::Reg(
+                } else {
-                            self.mark_non_callable(name.clone(), 1, term_loc, vr, code)
+                    at_1.unwrap_or(interm!(1))
-                        )
+                };
-                    } else {
-                        at_1.unwrap_or(interm!(1))
-                    };
 
-                let at_2 =
+                let at_2 = if let &Term::Var(ref vr, ref name) = terms[1].as_ref() {
-                    if let &Term::Var(ref vr, ref name) = terms[1].as_ref() {
+                    ArithmeticTerm::Reg(self.mark_non_callable(name.clone(), 2, term_loc, vr, code))
-                        ArithmeticTerm::Reg(
+                } else {
-                            self.mark_non_callable(name.clone(), 2, term_loc, vr, code)
+                    at_2.unwrap_or(interm!(2))
-                        )
+                };
-                    } else {
-                        at_2.unwrap_or(interm!(2))
-                    };
 
                 code.append(&mut lcode);
                 code.append(&mut rcode);
@@ -461,9 +448,9 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
                 code.push(compare_number_instr!(cmp, at_1, at_2));
             }
             &InlinedClauseType::IsAtom(..) => match terms[0].as_ref() {
-                &Term::Constant(_, Constant::Char(_)) |
+                &Term::Constant(_, Constant::Char(_))
-                &Term::Constant(_, Constant::EmptyList) |
+                | &Term::Constant(_, Constant::EmptyList)
-                &Term::Constant(_, Constant::Atom(..)) => {
+                | &Term::Constant(_, Constant::Atom(..)) => {
                     code.push(succeed!());
                 }
                 &Term::Var(ref vr, ref name) => {
@@ -528,11 +515,11 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
                 }
             },
             &InlinedClauseType::IsNumber(..) => match terms[0].as_ref() {
-                &Term::Constant(_, Constant::Float(_)) |
+                &Term::Constant(_, Constant::Float(_))
-                &Term::Constant(_, Constant::Rational(_)) |
+                | &Term::Constant(_, Constant::Rational(_))
-                &Term::Constant(_, Constant::Integer(_)) |
+                | &Term::Constant(_, Constant::Integer(_))
-                &Term::Constant(_, Constant::Fixnum(_)) |
+                | &Term::Constant(_, Constant::Fixnum(_))
-                &Term::Constant(_, Constant::Usize(_)) => {
+                | &Term::Constant(_, Constant::Usize(_)) => {
                     code.push(succeed!());
                 }
                 &Term::Var(ref vr, ref name) => {
@@ -558,9 +545,9 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
                 }
             },
             &InlinedClauseType::IsInteger(..) => match terms[0].as_ref() {
-                &Term::Constant(_, Constant::Integer(_)) |
+                &Term::Constant(_, Constant::Integer(_))
-                &Term::Constant(_, Constant::Fixnum(_)) |
+                | &Term::Constant(_, Constant::Fixnum(_))
-                &Term::Constant(_, Constant::Usize(_)) => {
+                | &Term::Constant(_, Constant::Usize(_)) => {
                     code.push(succeed!());
                 }
                 &Term::Var(ref vr, ref name) => {
@@ -615,14 +602,15 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
             &Term::Var(ref vr, ref name) => {
                 let mut target = vec![];
 
-                self.marker.mark_var(name.clone(), Level::Shallow, vr, term_loc, &mut target);
+                self.marker
+                    .mark_var(name.clone(), Level::Shallow, vr, term_loc, &mut target);
 
                 if !target.is_empty() {
                     code.extend(target.into_iter().map(Line::Query));
                 }
             }
-            &Term::Constant(_, ref c @ Constant::Integer(_)) |
+            &Term::Constant(_, ref c @ Constant::Integer(_))
-            &Term::Constant(_, ref c @ Constant::Fixnum(_)) => {
+            | &Term::Constant(_, ref c @ Constant::Fixnum(_)) => {
                 code.push(Line::Query(put_constant!(
                     Level::Shallow,
                     c.clone(),
@@ -655,14 +643,11 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
             }
         }
 
-        let at =
+        let at = if let &Term::Var(ref vr, ref name) = terms[1].as_ref() {
-            if let &Term::Var(ref vr, ref name) = terms[1].as_ref() {
+            ArithmeticTerm::Reg(self.mark_non_callable(name.clone(), 2, term_loc, vr, code))
-                ArithmeticTerm::Reg(
+        } else {
-                    self.mark_non_callable(name.clone(), 2, term_loc, vr, code)
+            at.unwrap_or(interm!(1))
-                )
+        };
-            } else {
-                at.unwrap_or(interm!(1))
-            };
 
         Ok(if use_default_call_policy {
             code.push(is_call_by_default!(temp_v!(1), at));
@@ -721,24 +706,18 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
                     &QueryTerm::GetLevelAndUnify(ref cell, ref var) => {
                         self.compile_get_level_and_unify(code, cell, var.clone(), term_loc)
                     }
-                    &QueryTerm::UnblockedCut(ref cell) => {
+                    &QueryTerm::UnblockedCut(ref cell) => self.compile_unblocked_cut(code, cell),
-                        self.compile_unblocked_cut(code, cell)
+                    &QueryTerm::BlockedCut => code.push(if chunk_num == 0 {
-                    }
+                        Line::Cut(CutInstruction::NeckCut)
-                    &QueryTerm::BlockedCut => {
+                    } else {
-                        code.push(if chunk_num == 0 {
+                        Line::Cut(CutInstruction::Cut(perm_v!(1)))
-                            Line::Cut(CutInstruction::NeckCut)
+                    }),
-                        } else {
-                            Line::Cut(CutInstruction::Cut(perm_v!(1)))
-                        })
-                    }
                     &QueryTerm::Clause(
                         _,
                         ClauseType::BuiltIn(BuiltInClauseType::Is(..)),
                         ref terms,
                         use_default_call_policy,
-                    ) => {
+                    ) => self.compile_is_call(terms, code, term_loc, use_default_call_policy)?,
-                        self.compile_is_call(terms, code, term_loc, use_default_call_policy)?
-                    }
                     &QueryTerm::Clause(_, ClauseType::Inlined(ref ct), ref terms, _) => {
                         self.compile_inlined(ct, terms, term_loc, code)?
                     }
@@ -772,7 +751,12 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
         }
     }
 
-    fn compile_cleanup(&mut self, code: &mut Code, conjunct_info: &ConjunctInfo, toc: &'a QueryTerm) {
+    fn compile_cleanup(
+        &mut self,
+        code: &mut Code,
+        conjunct_info: &ConjunctInfo,
+        toc: &'a QueryTerm,
+    ) {
         // add a proceed to bookend any trailing cuts.
         match toc {
             &QueryTerm::BlockedCut | &QueryTerm::UnblockedCut(..) => code.push(proceed!()),
@@ -786,7 +770,7 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
         if conjunct_info.allocates() {
             let offset = self.global_jmp_by_locs_offset;
 
-            if let Some(jmp_by_offset) = self.jmp_by_locs[offset ..].last_mut() {
+            if let Some(jmp_by_offset) = self.jmp_by_locs[offset..].last_mut() {
                 if *jmp_by_offset == dealloc_index {
                     *jmp_by_offset += 1;
                 }
@@ -905,32 +889,32 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
         self.add_conditional_call(code, term, num_perm_vars_left);
     }
 
-/*
+    /*
-    pub fn compile_query(&mut self, query: &'a Vec<QueryTerm>) -> Result<Code, CompilationError> {
+        pub fn compile_query(&mut self, query: &'a Vec<QueryTerm>) -> Result<Code, CompilationError> {
-        let iter = ChunkedIterator::from_term_sequence(query);
+            let iter = ChunkedIterator::from_term_sequence(query);
-        let conjunct_info = self.collect_var_data(iter);
+            let conjunct_info = self.collect_var_data(iter);
 
-        let mut code = Vec::new();
+            let mut code = Vec::new();
-        self.compile_seq_prelude(&conjunct_info, &mut code);
+            self.compile_seq_prelude(&conjunct_info, &mut code);
 
-        let iter = ChunkedIterator::from_term_sequence(query);
+            let iter = ChunkedIterator::from_term_sequence(query);
-        self.compile_seq(iter, &conjunct_info, &mut code, true)?;
+            self.compile_seq(iter, &conjunct_info, &mut code, true)?;
 
-        conjunct_info.mark_unsafe_vars(UnsafeVarMarker::new(), &mut code);
+            conjunct_info.mark_unsafe_vars(UnsafeVarMarker::new(), &mut code);
 
-        if let Some(query_term) = query.last() {
+            if let Some(query_term) = query.last() {
-            Self::compile_cleanup(&mut code, &conjunct_info, query_term);
+                Self::compile_cleanup(&mut code, &conjunct_info, query_term);
+            }
+
+            Ok(code)
         }
-
+    */
-        Ok(code)
-    }
-*/
 
     #[inline]
     fn increment_jmp_by_locs_by(&mut self, incr: usize) {
         let offset = self.global_jmp_by_locs_offset;
 
-        for loc in &mut self.jmp_by_locs[offset ..] {
+        for loc in &mut self.jmp_by_locs[offset..] {
             *loc += incr;
         }
     }
@@ -1077,7 +1061,7 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
 
             if skip_stub_try_me_else {
                 // skip the TryMeElse(0) also.
-                 self.increment_jmp_by_locs_by(2);
+                self.increment_jmp_by_locs_by(2);
             } else {
                 self.increment_jmp_by_locs_by(1);
             }
@@ -1105,7 +1089,7 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
 
         for (l, r) in split_pred {
             let skel_lower_bound = self.skeleton.clauses.len();
-            let code_segment = self.compile_pred_subseq(&clauses[l .. r], optimal_index)?;
+            let code_segment = self.compile_pred_subseq(&clauses[l..r], optimal_index)?;
             let clause_start_offset = code.len();
 
             if multi_seq {
@@ -1123,11 +1107,10 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
             if self.is_extensible {
                 let segment_is_indexed = to_indexing_line(&code_segment[0]).is_some();
 
-                for clause_index_info in self.skeleton.clauses[skel_lower_bound ..].iter_mut() {
+                for clause_index_info in self.skeleton.clauses[skel_lower_bound..].iter_mut() {
                     clause_index_info.clause_start +=
                         clause_start_offset + 2 * (segment_is_indexed as usize);
-                    clause_index_info.opt_arg_index_key +=
+                    clause_index_info.opt_arg_index_key += clause_start_offset + 1;
-                        clause_start_offset + 1;
                 }
             }
 

src/debray_allocator.rs

@@ -1,6 +1,7 @@
-use crate::indexmap::IndexMap;
+use indexmap::IndexMap;
 
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
+use prolog_parser::temp_v;
 
 use crate::allocator::*;
 use crate::fixtures::*;
@@ -293,9 +294,7 @@ impl<'a> Allocator<'a> for DebrayAllocator {
 
                 (pr, true)
             }
-            r => {
+            r => (r, false),
-                (r, false)
-            }
         };
 
         self.mark_reserved_var(var, lvl, cell, term_loc, target, r, is_new_var);

src/fixtures.rs

@@ -1,10 +1,10 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
 
 use crate::forms::*;
 use crate::instructions::*;
 use crate::iterators::*;
 
-use crate::indexmap::{IndexMap, IndexSet};
+use indexmap::{IndexMap, IndexSet};
 
 use std::cell::Cell;
 use std::collections::BTreeSet;
@@ -83,18 +83,17 @@ impl TempVarData {
 type VariableFixture<'a> = (VarStatus, Vec<&'a Cell<VarReg>>);
 
 #[derive(Debug)]
-pub struct VariableFixtures<'a>{
+pub struct VariableFixtures<'a> {
     perm_vars: IndexMap<Rc<Var>, VariableFixture<'a>>,
-    last_chunk_temp_vars: IndexSet<Rc<Var>>
+    last_chunk_temp_vars: IndexSet<Rc<Var>>,
 }
 
 impl<'a> VariableFixtures<'a> {
     pub fn new() -> Self {
         VariableFixtures {
             perm_vars: IndexMap::new(),
-            last_chunk_temp_vars: IndexSet::new()
+            last_chunk_temp_vars: IndexSet::new(),
         }
-
     }
 
     pub fn insert(&mut self, var: Rc<Var>, vs: VariableFixture<'a>) {
@@ -262,34 +261,32 @@ impl UnsafeVarMarker {
     pub fn new() -> Self {
         UnsafeVarMarker {
             unsafe_vars: IndexMap::new(),
-            safe_vars: IndexSet::new()
+            safe_vars: IndexSet::new(),
         }
     }
 
     pub fn from_safe_vars(safe_vars: IndexSet<RegType>) -> Self {
         UnsafeVarMarker {
             unsafe_vars: IndexMap::new(),
-            safe_vars
+            safe_vars,
         }
     }
 
     pub fn mark_safe_vars(&mut self, query_instr: &QueryInstruction) -> bool {
         match query_instr {
             &QueryInstruction::PutVariable(r @ RegType::Temp(_), _)
-          | &QueryInstruction::SetVariable(r) =>  {
+            | &QueryInstruction::SetVariable(r) => {
                 self.safe_vars.insert(r);
                 true
             }
-            _ => {
+            _ => false,
-                false
-            }
         }
     }
 
     pub fn mark_phase(&mut self, query_instr: &QueryInstruction, phase: usize) {
         match query_instr {
             &QueryInstruction::PutValue(r @ RegType::Perm(_), _)
-          | &QueryInstruction::SetValue(r) => {
+            | &QueryInstruction::SetValue(r) => {
                 let p = self.unsafe_vars.entry(r).or_insert(0);
                 *p = phase;
             }

src/forms.rs

@@ -1,13 +1,14 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
-use crate::prolog_parser_rebis::parser::OpDesc;
+use prolog_parser::parser::OpDesc;
+use prolog_parser::{clause_name, is_infix, is_postfix};
 
 use crate::clause_types::*;
 use crate::machine::machine_errors::*;
 use crate::machine::machine_indices::*;
-use crate::ordered_float::OrderedFloat;
 use crate::rug::{Integer, Rational};
+use ordered_float::OrderedFloat;
 
-use crate::indexmap::{IndexMap, IndexSet};
+use indexmap::{IndexMap, IndexSet};
 
 use slice_deque::*;
 
@@ -36,7 +37,7 @@ pub enum TopLevel {
 #[derive(Debug, Clone, Copy)]
 pub enum AppendOrPrepend {
     Append,
-    Prepend
+    Prepend,
 }
 
 impl AppendOrPrepend {
@@ -115,12 +116,8 @@ impl ListingSource {
 pub trait ClauseInfo {
     fn is_consistent(&self, clauses: &Vec<PredicateClause>) -> bool {
         match clauses.first() {
-            Some(cl) => {
+            Some(cl) => self.name() == cl.name() && self.arity() == cl.arity(),
-                self.name() == cl.name() && self.arity() == cl.arity()
+            None => true,
-            }
-            None => {
-                true
-            }
         }
     }
 
@@ -140,38 +137,25 @@ impl ClauseInfo for Term {
                             _ => Some(clause_name!(":-")),
                         }
                     }
-                    _ => {
+                    _ => Some(name.clone()),
-                        Some(name.clone())
-                    }
                 }
             }
-            Term::Constant(_, Constant::Atom(ref name, _)) => {
+            Term::Constant(_, Constant::Atom(ref name, _)) => Some(name.clone()),
-                Some(name.clone())
+            _ => None,
-            }
-            _ => {
-                None
-            }
         }
     }
 
     fn arity(&self) -> usize {
         match self {
-            Term::Clause(_, ref name, ref terms, _) =>
+            Term::Clause(_, ref name, ref terms, _) => match name.as_str() {
-                match name.as_str() {
+                ":-" => match terms.len() {
-                    ":-" => {
+                    1 => 0,
-                        match terms.len() {
+                    2 => terms[0].arity(),
-                            1 => 0,
+                    _ => terms.len(),
-                            2 => terms[0].arity(),
-                            _ => terms.len(),
-                        }
-                    }
-                    _ => {
-                        terms.len()
-                    }
                 },
-            _ => {
+                _ => terms.len(),
-                0
+            },
-            }
+            _ => 0,
         }
     }
 }
@@ -189,23 +173,15 @@ impl ClauseInfo for Rule {
 impl ClauseInfo for PredicateClause {
     fn name(&self) -> Option<ClauseName> {
         match self {
-            &PredicateClause::Fact(ref term, ..) => {
+            &PredicateClause::Fact(ref term, ..) => term.name(),
-                term.name()
+            &PredicateClause::Rule(ref rule, ..) => rule.name(),
-            }
-            &PredicateClause::Rule(ref rule, ..) => {
-                rule.name()
-            }
         }
     }
 
     fn arity(&self) -> usize {
         match self {
-            &PredicateClause::Fact(ref term, ..) => {
+            &PredicateClause::Fact(ref term, ..) => term.arity(),
-                term.arity()
+            &PredicateClause::Rule(ref rule, ..) => rule.arity(),
-            }
-            &PredicateClause::Rule(ref rule, ..) => {
-                rule.arity()
-            }
         }
     }
 }
@@ -222,11 +198,9 @@ impl PredicateClause {
     // TODO: add this to `Term` in `prolog_parser` like `first_arg`.
     pub fn args(&self) -> Option<&[Box<Term>]> {
         match *self {
-            PredicateClause::Fact(ref term, ..) => {
+            PredicateClause::Fact(ref term, ..) => match term {
-                match term {
+                Term::Clause(_, _, args, _) => Some(&args),
-                    Term::Clause(_, _, args, _) => Some(&args),
+                _ => None,
-                    _ => None,
-                }
             },
             PredicateClause::Rule(ref rule, ..) => {
                 if rule.head.1.is_empty() {
@@ -240,14 +214,11 @@ impl PredicateClause {
 
     pub fn arity(&self) -> usize {
         match self {
-            &PredicateClause::Fact(ref term, ..) => {
+            &PredicateClause::Fact(ref term, ..) => term.arity(),
-                term.arity()
-            }
             &PredicateClause::Rule(ref rule, ..) => {
                 if rule.head.0.as_str() == ":" && rule.head.1.len() == 2 {
                     match (rule.head.1)[0].as_ref() {
-                        &Term::Constant(_, Constant::Atom(..)) => {
+                        &Term::Constant(_, Constant::Atom(..)) => {}
-                        }
                         _ => {
                             return 2;
                         }
@@ -321,7 +292,7 @@ pub enum Declaration {
 pub struct OpDecl {
     pub prec: usize,
     pub spec: Specifier,
-    pub name: ClauseName
+    pub name: ClauseName,
 }
 
 impl OpDecl {
@@ -345,7 +316,7 @@ impl OpDecl {
             XFY | XFX | YFX => Fixity::In,
             XF | YF => Fixity::Post,
             FX | FY => Fixity::Pre,
-            _ => unreachable!()
+            _ => unreachable!(),
         }
     }
 
@@ -356,12 +327,12 @@ impl OpDecl {
             Some(cell) => {
                 return Some(cell.shared_op_desc().replace((self.prec, self.spec)));
             }
-            None => {
+            None => {}
-            }
         }
 
-        op_dir.insert(key, OpDirValue::new(self.spec, self.prec))
+        op_dir
-              .map(|op_dir_value| op_dir_value.shared_op_desc().get())
+            .insert(key, OpDirValue::new(self.spec, self.prec))
+            .map(|op_dir_value| op_dir_value.shared_op_desc().get())
     }
 
     pub fn submit(
@@ -419,11 +390,7 @@ pub fn fetch_op_spec_from_existing(
     spec.or_else(|| fetch_op_spec(name, arity, op_dir))
 }
 
-pub fn fetch_op_spec(
+pub fn fetch_op_spec(name: ClauseName, arity: usize, op_dir: &OpDir) -> Option<SharedOpDesc> {
-    name: ClauseName,
-    arity: usize,
-    op_dir: &OpDir,
-) -> Option<SharedOpDesc> {
     match arity {
         2 => op_dir
             .get(&(name, Fixity::In))
@@ -451,9 +418,7 @@ pub fn fetch_op_spec(
                     }
                 })
         }
-        _ => {
+        _ => None,
-            None
-        }
     }
 }
 
@@ -499,7 +464,6 @@ impl Module {
     }
 }
 
-
 #[derive(Debug, Clone)]
 pub enum Number {
     Float(OrderedFloat<f64>),
@@ -559,7 +523,6 @@ impl Into<HeapCellValue> for Number {
     }
 }
 
-
 impl Number {
     #[inline]
     pub fn is_positive(&self) -> bool {
@@ -594,12 +557,13 @@ impl Number {
     #[inline]
     pub fn abs(self) -> Self {
         match self {
-            Number::Fixnum(n) =>
+            Number::Fixnum(n) => {
                 if let Some(n) = n.checked_abs() {
                     Number::from(n)
                 } else {
                     Number::from(Integer::from(n).abs())
                 }
+            }
             Number::Integer(n) => Number::from(Integer::from(n.abs_ref())),
             Number::Float(f) => Number::Float(OrderedFloat(f.abs())),
             Number::Rational(r) => Number::from(Rational::from(r.abs_ref())),
@@ -624,15 +588,13 @@ impl OptArgIndexKey {
     #[inline]
     pub fn arg_num(&self) -> usize {
         match &self {
-            OptArgIndexKey::Constant(arg_num, ..) |
+            OptArgIndexKey::Constant(arg_num, ..)
-            OptArgIndexKey::Structure(arg_num, ..) |
+            | OptArgIndexKey::Structure(arg_num, ..)
-            OptArgIndexKey::List(arg_num, _) => {
+            | OptArgIndexKey::List(arg_num, _) => {
                 // these are always at least 1.
                 *arg_num
             }
-            OptArgIndexKey::None => {
+            OptArgIndexKey::None => 0,
-                0
-            }
         }
     }
 
@@ -644,27 +606,22 @@ impl OptArgIndexKey {
     #[inline]
     pub fn switch_on_term_loc(&self) -> Option<usize> {
         match &self {
-            OptArgIndexKey::Constant(_, loc, ..) |
+            OptArgIndexKey::Constant(_, loc, ..)
-            OptArgIndexKey::Structure(_, loc, ..) |
+            | OptArgIndexKey::Structure(_, loc, ..)
-            OptArgIndexKey::List(_, loc) => {
+            | OptArgIndexKey::List(_, loc) => Some(*loc),
-                Some(*loc)
+            OptArgIndexKey::None => None,
-            }
-            OptArgIndexKey::None => {
-                None
-            }
         }
     }
 
     #[inline]
     pub fn set_switch_on_term_loc(&mut self, value: usize) {
         match self {
-            OptArgIndexKey::Constant(_, ref mut loc, ..) |
+            OptArgIndexKey::Constant(_, ref mut loc, ..)
-            OptArgIndexKey::Structure(_, ref mut loc, ..) |
+            | OptArgIndexKey::Structure(_, ref mut loc, ..)
-            OptArgIndexKey::List(_, ref mut loc) => {
+            | OptArgIndexKey::List(_, ref mut loc) => {
                 *loc = value;
             }
-            OptArgIndexKey::None => {
+            OptArgIndexKey::None => {}
-            }
         }
     }
 }
@@ -673,13 +630,12 @@ impl AddAssign<usize> for OptArgIndexKey {
     #[inline]
     fn add_assign(&mut self, n: usize) {
         match self {
-            OptArgIndexKey::Constant(_, ref mut o, ..) |
+            OptArgIndexKey::Constant(_, ref mut o, ..)
-            OptArgIndexKey::List(_, ref mut o) |
+            | OptArgIndexKey::List(_, ref mut o)
-            OptArgIndexKey::Structure(_, ref mut o, ..) => {
+            | OptArgIndexKey::Structure(_, ref mut o, ..) => {
                 *o += n;
             }
-            OptArgIndexKey::None => {
+            OptArgIndexKey::None => {}
-            }
         }
     }
 }
@@ -755,5 +711,21 @@ impl PredicateSkeleton {
             clauses: self.clauses,
         }
     }
-    */
+     */
+
+    pub fn target_pos_of_clause_clause_loc(
+        &self,
+        clause_clause_loc: usize,
+        clause_assert_margin: usize,
+    ) -> usize {
+        let search_result = self.clause_clause_locs[0..clause_assert_margin]
+            .binary_search_by(|loc| clause_clause_loc.cmp(&loc));
+
+        search_result.unwrap_or_else(|_| {
+            self.clause_clause_locs[clause_assert_margin..]
+                .binary_search_by(|loc| loc.cmp(&clause_clause_loc))
+                .unwrap()
+                + clause_assert_margin
+        })
+    }
 }

src/heap_iter.rs

@@ -1,7 +1,7 @@
 use crate::machine::machine_indices::*;
 use crate::machine::machine_state::*;
 
-use crate::indexmap::IndexSet;
+use indexmap::IndexSet;
 
 use std::cmp::Ordering;
 use std::ops::Deref;
@@ -29,31 +29,21 @@ impl<'a> HCPreOrderIterator<'a> {
     fn follow_heap(&mut self, h: usize) -> Addr {
         match &self.machine_st.heap[h] {
             &HeapCellValue::NamedStr(arity, _, _) => {
-                for idx in (1 .. arity + 1).rev() {
+                for idx in (1..arity + 1).rev() {
                     self.state_stack.push(Addr::HeapCell(h + idx));
                 }
 
                 Addr::Str(h)
             }
-            &HeapCellValue::Addr(a) => {
+            &HeapCellValue::Addr(a) => self.follow(a),
-                self.follow(a)
+            HeapCellValue::PartialString(..) => self.follow(Addr::PStrLocation(h, 0)),
-            }
+            HeapCellValue::Atom(..)
-            HeapCellValue::PartialString(..) => {
+            | HeapCellValue::DBRef(_)
-                self.follow(Addr::PStrLocation(h, 0))
+            | HeapCellValue::Integer(_)
-            }
+            | HeapCellValue::Rational(_) => Addr::Con(h),
-            HeapCellValue::Atom(..) | HeapCellValue::DBRef(_)
+            HeapCellValue::LoadStatePayload(_) => Addr::LoadStatePayload(h),
-          | HeapCellValue::Integer(_) | HeapCellValue::Rational(_) => {
+            HeapCellValue::Stream(_) => Addr::Stream(h),
-                Addr::Con(h)
+            HeapCellValue::TcpListener(_) => Addr::TcpListener(h),
-            }
-            HeapCellValue::LoadStatePayload(_) => {
-                Addr::LoadStatePayload(h)
-            }
-            HeapCellValue::Stream(_) => {
-                Addr::Stream(h)
-            }
-            HeapCellValue::TcpListener(_) => {
-                Addr::TcpListener(h)
-            }
         }
     }
 
@@ -71,10 +61,12 @@ impl<'a> HCPreOrderIterator<'a> {
                 da
             }
             Addr::PStrLocation(h, n) => {
-                if let &HeapCellValue::PartialString(ref pstr, has_tail) = &self.machine_st.heap[h] {
+                if let &HeapCellValue::PartialString(ref pstr, has_tail) = &self.machine_st.heap[h]
-                    if let Some(c) = pstr.range_from(n ..).next() {
+                {
+                    if let Some(c) = pstr.range_from(n..).next() {
                         if !pstr.at_end(n + c.len_utf8()) {
-                            self.state_stack.push(Addr::PStrLocation(h, n + c.len_utf8()));
+                            self.state_stack
+                                .push(Addr::PStrLocation(h, n + c.len_utf8()));
                         } else if has_tail {
                             self.state_stack.push(Addr::HeapCell(h + 1));
                         } else {
@@ -95,8 +87,9 @@ impl<'a> HCPreOrderIterator<'a> {
                 self.follow_heap(s) // record terms of structure.
             }
             Addr::Con(h) => {
-                if let &HeapCellValue::PartialString(ref pstr, has_tail) = &self.machine_st.heap[h] {
+                if let &HeapCellValue::PartialString(ref pstr, has_tail) = &self.machine_st.heap[h]
-                    if let Some(c) = pstr.range_from(0 ..).next() {
+                {
+                    if let Some(c) = pstr.range_from(0..).next() {
                         self.state_stack.push(Addr::PStrLocation(h, c.len_utf8()));
                         self.state_stack.push(Addr::Char(c));
 
@@ -110,9 +103,7 @@ impl<'a> HCPreOrderIterator<'a> {
                     Addr::Con(h)
                 }
             }
-            da => {
+            da => da,
-                da
-            }
         }
     }
 }
@@ -125,7 +116,9 @@ impl<'a> Iterator for HCPreOrderIterator<'a> {
     }
 }
 
-pub trait MutStackHCIterator<'b> where Self: Iterator
+pub trait MutStackHCIterator<'b>
+where
+    Self: Iterator,
 {
     type MutStack;
 
@@ -178,7 +171,8 @@ impl<'a> Iterator for HCPostOrderIterator<'a> {
                     }
                     &HeapCellValue::Addr(Addr::PStrLocation(h, n)) => {
                         match &self.machine_st.heap[h] {
-                            &HeapCellValue::PartialString(..) => {// ref pstr, _) => {
+                            &HeapCellValue::PartialString(..) => {
+                                // ref pstr, _) => {
                                 /*
                                 let c = pstr.range_from(n ..).next().unwrap();
                                 let next_n = n + c.len_utf8();
@@ -215,7 +209,7 @@ impl MachineState {
         HCPostOrderIterator::new(HCPreOrderIterator::new(self, a))
     }
 
-    pub fn acyclic_pre_order_iter<'a>(&'a self, a: Addr,) -> HCAcyclicIterator<'a> {
+    pub fn acyclic_pre_order_iter<'a>(&'a self, a: Addr) -> HCAcyclicIterator<'a> {
         HCAcyclicIterator::new(HCPreOrderIterator::new(self, a))
     }
 
@@ -270,8 +264,7 @@ impl<'b, 'a: 'b> MutStackHCIterator<'b> for HCAcyclicIterator<'a> {
     }
 }
 
-impl<'a> Iterator for HCAcyclicIterator<'a>
+impl<'a> Iterator for HCAcyclicIterator<'a> {
-{
     type Item = Addr;
 
     fn next(&mut self) -> Option<Self::Item> {
@@ -315,8 +308,7 @@ impl<'a> HCZippedAcyclicIterator<'a> {
     }
 }
 
-impl<'a> Iterator for HCZippedAcyclicIterator<'a>
+impl<'a> Iterator for HCZippedAcyclicIterator<'a> {
-{
     type Item = (Addr, Addr);
 
     fn next(&mut self) -> Option<Self::Item> {
@@ -341,9 +333,7 @@ impl<'a> Iterator for HCZippedAcyclicIterator<'a>
                 self.first_to_expire = Ordering::Less;
                 None
             }
-            _ => {
+            _ => None,
-                None
-            }
         }
     }
 }

src/heap_print.rs

@@ -1,4 +1,10 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
+use prolog_parser::{
+    alpha_numeric_char, capital_letter_char, clause_name, cut_char, decimal_digit_char,
+    graphic_token_char, is_fx, is_infix, is_postfix, is_prefix, is_xf, is_xfx, is_xfy, is_yfx,
+    semicolon_char, sign_char, single_quote_char, small_letter_char, solo_char,
+    variable_indicator_char,
+};
 
 use crate::clause_types::*;
 use crate::forms::*;
@@ -7,14 +13,14 @@ use crate::machine::heap::*;
 use crate::machine::machine_indices::*;
 use crate::machine::machine_state::*;
 use crate::machine::streams::*;
-use crate::ordered_float::OrderedFloat;
 use crate::rug::{Integer, Rational};
+use ordered_float::OrderedFloat;
 
-use crate::indexmap::{IndexMap, IndexSet};
+use indexmap::{IndexMap, IndexSet};
 
 use std::cell::Cell;
 use std::convert::TryFrom;
-use std::iter::{FromIterator, once};
+use std::iter::{once, FromIterator};
 use std::net::{IpAddr, TcpListener};
 use std::ops::{Range, RangeFrom};
 use std::rc::Rc;
@@ -99,10 +105,7 @@ impl<'a> HCPreOrderIterator<'a> {
             None => return false,
         };
 
-        let mut parent_spec = DirectedOp::Left(
+        let mut parent_spec = DirectedOp::Left(clause_name!("-"), SharedOpDesc::new(200, FY));
-            clause_name!("-"),
-            SharedOpDesc::new(200, FY),
-        );
 
         loop {
             match self.machine_st.store(self.machine_st.deref(addr)) {
@@ -154,12 +157,13 @@ fn char_to_string(is_quoted: bool, c: char) -> String {
         '\u{07}' if is_quoted => "\\a".to_string(), // UTF-8 alert
         '"' if is_quoted => "\\\"".to_string(),
         '\\' if is_quoted => "\\\\".to_string(),
-        '\'' | '\n' | '\r' | '\t' | '\u{0b}' | '\u{0c}' | '\u{08}' | '\u{07}' | '"' | '\\' =>
+        '\'' | '\n' | '\r' | '\t' | '\u{0b}' | '\u{0c}' | '\u{08}' | '\u{07}' | '"' | '\\' => {
-            c.to_string(),
+            c.to_string()
-        '\u{a0}' ..= '\u{d6}' => c.to_string(),
+        }
-        '\u{d8}' ..= '\u{f6}' => c.to_string(),
+        '\u{a0}'..='\u{d6}' => c.to_string(),
-        '\u{f8}' ..= '\u{74f}' => c.to_string(),
+        '\u{d8}'..='\u{f6}' => c.to_string(),
-        '\x20' ..= '\x7e' => c.to_string(),
+        '\u{f8}'..='\u{74f}' => c.to_string(),
+        '\x20'..='\x7e' => c.to_string(),
         _ => format!("\\x{:x}\\", c as u32),
     }
 }
@@ -271,25 +275,13 @@ fn is_numbered_var(ct: &ClauseType, arity: usize) -> bool {
 #[inline]
 fn negated_op_needs_bracketing(iter: &HCPreOrderIterator, op: &Option<DirectedOp>) -> bool {
     if let Some(ref op) = op {
-        op.is_negative_sign() &&
+        op.is_negative_sign()
-            iter.leftmost_leaf_has_property(|addr, heap| {
+            && iter.leftmost_leaf_has_property(|addr, heap| match Number::try_from((addr, heap)) {
-                match Number::try_from((addr, heap)) {
+                Ok(Number::Fixnum(n)) => n > 0,
-                    Ok(Number::Fixnum(n)) => {
+                Ok(Number::Float(f)) => f > OrderedFloat(0f64),
-                        n > 0
+                Ok(Number::Integer(n)) => &*n > &0,
-                    }
+                Ok(Number::Rational(n)) => &*n > &0,
-                    Ok(Number::Float(f)) => {
+                _ => false,
-                        f > OrderedFloat(0f64)
-                    }
-                    Ok(Number::Integer(n)) => {
-                        &*n > &0
-                    }
-                    Ok(Number::Rational(n)) => {
-                        &*n > &0
-                    }
-                    _ => {
-                        false
-                    }
-                }
             })
     } else {
         false
@@ -298,8 +290,8 @@ fn negated_op_needs_bracketing(iter: &HCPreOrderIterator, op: &Option<DirectedOp
 
 fn numbervar(n: Integer) -> Var {
     static CHAR_CODES: [char; 26] = [
-        'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
+        'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R',
-        'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
+        'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
     ];
 
     let i = n.mod_u(26) as usize;
@@ -332,9 +324,7 @@ impl MachineState {
                     None
                 }
             }
-            _ => {
+            _ => None,
-                None
-            }
         }
     }
 }
@@ -446,8 +436,7 @@ fn non_quoted_graphic_token<Iter: Iterator<Item = char>>(mut iter: Iter, c: char
     }
 }
 
-pub(super)
+pub(super) fn non_quoted_token<Iter: Iterator<Item = char>>(mut iter: Iter) -> bool {
-fn non_quoted_token<Iter: Iterator<Item = char>>(mut iter: Iter) -> bool {
     if let Some(c) = iter.next() {
         if small_letter_char!(c) {
             iter.all(|c| alpha_numeric_char!(c))
@@ -505,37 +494,37 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
             max_depth: 0,
         }
     }
-/*
+    /*
-    pub fn from_heap_locs(
+        pub fn from_heap_locs(
-        machine_st: &'a MachineState,
+            machine_st: &'a MachineState,
-        op_dir: &'a OpDir,
+            op_dir: &'a OpDir,
-        output: Outputter,
+            output: Outputter,
-    ) -> Self {
+        ) -> Self {
-        let mut printer = Self::new(machine_st, op_dir, output);
+            let mut printer = Self::new(machine_st, op_dir, output);
 
-        printer.toplevel_spec = Some(DirectedOp::Right(
+            printer.toplevel_spec = Some(DirectedOp::Right(
-            clause_name!("="),
+                clause_name!("="),
-            SharedOpDesc::new(700, XFX),
+                SharedOpDesc::new(700, XFX),
-        ));
+            ));
 
-        printer.heap_locs = reverse_heap_locs(machine_st);
+            printer.heap_locs = reverse_heap_locs(machine_st);
 
-        printer
+            printer
-    }
-*/
-/*
-    pub fn drop_toplevel_spec(&mut self) {
-        self.toplevel_spec = None;
-    }
-*/
-/*
-    #[inline]
-    pub fn see_all_locs(&mut self) {
-        for key in self.heap_locs.keys().cloned() {
-            self.printed_vars.insert(key);
         }
-    }
+    */
-*/
+    /*
+        pub fn drop_toplevel_spec(&mut self) {
+            self.toplevel_spec = None;
+        }
+    */
+    /*
+        #[inline]
+        pub fn see_all_locs(&mut self) {
+            for key in self.heap_locs.keys().cloned() {
+                self.printed_vars.insert(key);
+            }
+        }
+    */
 
     #[inline]
     fn ambiguity_check(&self, atom: &str) -> bool {
@@ -555,7 +544,8 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
                 iter.stack().pop();
 
                 self.state_stack.push(TokenOrRedirect::Op(ct.name(), spec));
-                self.state_stack.push(TokenOrRedirect::Atom(clause_name!("...")));
+                self.state_stack
+                    .push(TokenOrRedirect::Atom(clause_name!("...")));
 
                 return;
             }
@@ -579,7 +569,8 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
             if self.check_max_depth(&mut max_depth) {
                 iter.stack().pop();
 
-                self.state_stack.push(TokenOrRedirect::Atom(clause_name!("...")));
+                self.state_stack
+                    .push(TokenOrRedirect::Atom(clause_name!("...")));
                 self.state_stack.push(TokenOrRedirect::Op(ct.name(), spec));
 
                 return;
@@ -587,7 +578,10 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
 
             let left_directed_op = DirectedOp::Left(ct.name(), spec.clone());
 
-            self.state_stack.push(TokenOrRedirect::CompositeRedirect(max_depth, left_directed_op));
+            self.state_stack.push(TokenOrRedirect::CompositeRedirect(
+                max_depth,
+                left_directed_op,
+            ));
             self.state_stack.push(TokenOrRedirect::Op(ct.name(), spec));
         } else {
             match ct.name().as_str() {
@@ -602,9 +596,11 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
                 iter.stack().pop();
                 iter.stack().pop();
 
-                self.state_stack.push(TokenOrRedirect::Atom(clause_name!("...")));
+                self.state_stack
+                    .push(TokenOrRedirect::Atom(clause_name!("...")));
                 self.state_stack.push(TokenOrRedirect::Op(ct.name(), spec));
-                self.state_stack.push(TokenOrRedirect::Atom(clause_name!("...")));
+                self.state_stack
+                    .push(TokenOrRedirect::Atom(clause_name!("...")));
 
                 return;
             }
@@ -612,11 +608,15 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
             let left_directed_op = DirectedOp::Left(ct.name(), spec.clone());
             let right_directed_op = DirectedOp::Right(ct.name(), spec.clone());
 
-            self.state_stack
+            self.state_stack.push(TokenOrRedirect::CompositeRedirect(
-                .push(TokenOrRedirect::CompositeRedirect(max_depth, left_directed_op));
+                max_depth,
+                left_directed_op,
+            ));
             self.state_stack.push(TokenOrRedirect::Op(ct.name(), spec));
-            self.state_stack
+            self.state_stack.push(TokenOrRedirect::CompositeRedirect(
-                .push(TokenOrRedirect::CompositeRedirect(max_depth, right_directed_op));
+                max_depth,
+                right_directed_op,
+            ));
         }
     }
 
@@ -626,15 +626,15 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
         mut max_depth: usize,
         arity: usize,
         name: ClauseName,
-    ) -> bool
+    ) -> bool {
-    {
         if self.check_max_depth(&mut max_depth) {
-            for _ in 0 .. arity {
+            for _ in 0..arity {
                 iter.stack().pop();
             }
 
             self.state_stack.push(TokenOrRedirect::Close);
-            self.state_stack.push(TokenOrRedirect::Atom(clause_name!("...")));
+            self.state_stack
+                .push(TokenOrRedirect::Atom(clause_name!("...")));
             self.state_stack.push(TokenOrRedirect::Open);
 
             self.state_stack.push(TokenOrRedirect::Atom(name));
@@ -644,8 +644,9 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
 
         self.state_stack.push(TokenOrRedirect::Close);
 
-        for _ in 0 .. arity {
+        for _ in 0..arity {
-            self.state_stack.push(TokenOrRedirect::FunctorRedirect(max_depth));
+            self.state_stack
+                .push(TokenOrRedirect::FunctorRedirect(max_depth));
             self.state_stack.push(TokenOrRedirect::Comma);
         }
 
@@ -662,12 +663,13 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
         iter: &mut HCPreOrderIterator,
         mut max_depth: usize,
         name: ClauseName,
-        spec: SharedOpDesc)
+        spec: SharedOpDesc,
-    {
+    ) {
         if self.check_max_depth(&mut max_depth) {
             iter.stack().pop();
 
-            self.state_stack.push(TokenOrRedirect::Atom(clause_name!("...")));
+            self.state_stack
+                .push(TokenOrRedirect::Atom(clause_name!("...")));
             self.state_stack.push(TokenOrRedirect::Space);
             self.state_stack.push(TokenOrRedirect::Atom(name));
 
@@ -676,7 +678,8 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
 
         let op = DirectedOp::Left(name.clone(), spec);
 
-        self.state_stack.push(TokenOrRedirect::CompositeRedirect(max_depth, op));
+        self.state_stack
+            .push(TokenOrRedirect::CompositeRedirect(max_depth, op));
         self.state_stack.push(TokenOrRedirect::Space);
         self.state_stack.push(TokenOrRedirect::Atom(name));
     }
@@ -687,14 +690,15 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
         mut max_depth: usize,
         name: ClauseName,
         spec: SharedOpDesc,
-    )
+    ) {
-    {
         if self.check_max_depth(&mut max_depth) {
             iter.stack().pop();
 
-            self.state_stack.push(TokenOrRedirect::Atom(clause_name!("...")));
+            self.state_stack
+                .push(TokenOrRedirect::Atom(clause_name!("...")));
             self.state_stack.push(TokenOrRedirect::BarAsOp);
-            self.state_stack.push(TokenOrRedirect::Atom(clause_name!("...")));
+            self.state_stack
+                .push(TokenOrRedirect::Atom(clause_name!("...")));
 
             return;
         }
@@ -702,25 +706,32 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
         let left_directed_op = DirectedOp::Left(name.clone(), spec.clone());
         let right_directed_op = DirectedOp::Right(name.clone(), spec.clone());
 
-        self.state_stack.push(TokenOrRedirect::CompositeRedirect(max_depth, left_directed_op));
+        self.state_stack.push(TokenOrRedirect::CompositeRedirect(
+            max_depth,
+            left_directed_op,
+        ));
         self.state_stack.push(TokenOrRedirect::BarAsOp);
-        self.state_stack.push(TokenOrRedirect::CompositeRedirect(max_depth, right_directed_op));
+        self.state_stack.push(TokenOrRedirect::CompositeRedirect(
+            max_depth,
+            right_directed_op,
+        ));
     }
 
-    fn format_curly_braces(&mut self, iter: &mut HCPreOrderIterator, mut max_depth: usize) -> bool
+    fn format_curly_braces(&mut self, iter: &mut HCPreOrderIterator, mut max_depth: usize) -> bool {
-    {
         if self.check_max_depth(&mut max_depth) {
             iter.stack().pop();
 
             self.state_stack.push(TokenOrRedirect::RightCurly);
-            self.state_stack.push(TokenOrRedirect::Atom(clause_name!("...")));
+            self.state_stack
+                .push(TokenOrRedirect::Atom(clause_name!("...")));
             self.state_stack.push(TokenOrRedirect::LeftCurly);
 
             return false;
         }
 
         self.state_stack.push(TokenOrRedirect::RightCurly);
-        self.state_stack.push(TokenOrRedirect::FunctorRedirect(max_depth));
+        self.state_stack
+            .push(TokenOrRedirect::FunctorRedirect(max_depth));
         self.state_stack.push(TokenOrRedirect::LeftCurly);
 
         true
@@ -795,18 +806,12 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
         }
 
         match addr {
-            Addr::Lis(h) | Addr::Str(h) => {
+            Addr::Lis(h) | Addr::Str(h) => Some(format!("{}", h)),
-                Some(format!("{}", h))
-            }
             _ => {
                 if let Some(r) = addr.as_var() {
                     match r {
-                        Ref::StackCell(fr, sc) => {
+                        Ref::StackCell(fr, sc) => Some(format!("_s_{}_{}", fr, sc)),
-                            Some(format!("_s_{}_{}", fr, sc))
+                        Ref::HeapCell(h) | Ref::AttrVar(h) => Some(format!("_{}", h)),
-                        }
-                        Ref::HeapCell(h) | Ref::AttrVar(h) => {
-                            Some(format!("_{}", h))
-                        }
                     }
                 } else {
                     None
@@ -818,8 +823,12 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
     fn record_children_as_non_cyclic(&mut self, addr: &Addr) {
         match addr {
             &Addr::Lis(l) => {
-                let c1 = self.machine_st.store(self.machine_st.deref(Addr::HeapCell(l)));
+                let c1 = self
-                let c2 = self.machine_st.store(self.machine_st.deref(Addr::HeapCell(l + 1)));
+                    .machine_st
+                    .store(self.machine_st.deref(Addr::HeapCell(l)));
+                let c2 = self
+                    .machine_st
+                    .store(self.machine_st.deref(Addr::HeapCell(l + 1)));
 
                 if let Some(c) = functor_location(&c1) {
                     self.non_cyclic_terms.insert(c);
@@ -830,18 +839,17 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
                 }
             }
             &Addr::Str(s) => {
-                let arity =
+                let arity = match &self.machine_st.heap[s] {
-                    match &self.machine_st.heap[s] {
+                    HeapCellValue::NamedStr(arity, ..) => arity,
-                        HeapCellValue::NamedStr(arity, ..) => {
+                    _ => {
-                            arity
+                        unreachable!()
-                        }
+                    }
-                        _ => {
+                };
-                            unreachable!()
-                        }
-                    };
 
-                for i in 1 .. arity + 1 {
+                for i in 1..arity + 1 {
-                    let c = self.machine_st.store(self.machine_st.deref(Addr::HeapCell(s + i)));
+                    let c = self
+                        .machine_st
+                        .store(self.machine_st.deref(Addr::HeapCell(s + i)));
 
                     if let Some(c) = functor_location(&c) {
                         self.non_cyclic_terms.insert(c);
@@ -856,15 +864,11 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
                     self.non_cyclic_terms.insert(c);
                 }
             }
-            _ => {
+            _ => {}
-            }
         }
     }
 
-    fn check_for_seen(
+    fn check_for_seen(&mut self, iter: &mut HCPreOrderIterator) -> Option<Addr> {
-        &mut self,
-        iter: &mut HCPreOrderIterator,
-    ) -> Option<Addr> {
         iter.stack().last().cloned().and_then(|addr| {
             let addr = self.machine_st.store(self.machine_st.deref(addr));
 
@@ -889,9 +893,7 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
                 }
                 None => {
                     let offset = match functor_location(&addr) {
-                        Some(offset) => {
+                        Some(offset) => offset,
-                            offset
-                        }
                         None => {
                             return iter.next();
                         }
@@ -1036,19 +1038,17 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
 
                 let rdiv_ct = clause_name!("rdiv");
 
-                let left_directed_op =
+                let left_directed_op = if spec.prec() > 0 {
-                    if spec.prec() > 0 {
+                    Some(DirectedOp::Left(rdiv_ct.clone(), spec.clone()))
-                        Some(DirectedOp::Left(rdiv_ct.clone(), spec.clone()))
+                } else {
-                    } else {
+                    None
-                        None
+                };
-                    };
 
-                let right_directed_op =
+                let right_directed_op = if spec.prec() > 0 {
-                    if spec.prec() > 0 {
+                    Some(DirectedOp::Right(rdiv_ct.clone(), spec.clone()))
-                        Some(DirectedOp::Right(rdiv_ct.clone(), spec.clone()))
+                } else {
-                    } else {
+                    None
-                        None
+                };
-                    };
 
                 if spec.prec() > 0 {
                     self.state_stack.push(TokenOrRedirect::Number(
@@ -1056,10 +1056,8 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
                         left_directed_op,
                     ));
 
-                    self.state_stack.push(TokenOrRedirect::Op(
+                    self.state_stack
-                        rdiv_ct,
+                        .push(TokenOrRedirect::Op(rdiv_ct, spec.clone()));
-                        spec.clone(),
-                    ));
 
                     self.state_stack.push(TokenOrRedirect::Number(
                         Number::from(r.numer()),
@@ -1068,17 +1066,13 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
                 } else {
                     self.state_stack.push(TokenOrRedirect::Close);
 
-                    self.state_stack.push(TokenOrRedirect::Number(
+                    self.state_stack
-                        Number::from(r.denom()),
+                        .push(TokenOrRedirect::Number(Number::from(r.denom()), None));
-                        None,
-                    ));
 
                     self.state_stack.push(TokenOrRedirect::Comma);
 
-                    self.state_stack.push(TokenOrRedirect::Number(
+                    self.state_stack
-                        Number::from(r.numer()),
+                        .push(TokenOrRedirect::Number(Number::from(r.numer()), None));
-                        None,
-                    ));
 
                     self.state_stack.push(TokenOrRedirect::Open);
                     self.state_stack.push(TokenOrRedirect::Atom(rdiv_ct));
@@ -1092,8 +1086,7 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
         }
     }
 
-    fn print_char(&mut self, is_quoted: bool, c: char)
+    fn print_char(&mut self, is_quoted: bool, c: char) {
-    {
         if non_quoted_token(once(c)) {
             let c = char_to_string(false, c);
 
@@ -1120,46 +1113,37 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
     fn print_proper_string(&mut self, buf: String, max_depth: usize) {
         self.push_char('"');
 
-        let buf =
+        let buf = if max_depth == 0 {
-            if max_depth == 0 {
+            String::from_iter(buf.chars().map(|c| char_to_string(self.quoted, c)))
-                String::from_iter(buf.chars().map(|c| {
+        } else {
-                    char_to_string(self.quoted, c)
+            let mut char_count = 0;
-                }))
+            let mut buf = String::from_iter(buf.chars().take(max_depth).map(|c| {
-            } else {
+                char_count += 1;
-                let mut char_count = 0;
+                char_to_string(self.quoted, c)
-                let mut buf =
+            }));
-                    String::from_iter(buf.chars().take(max_depth).map(|c| {
-                        char_count += 1;
-                        char_to_string(self.quoted, c)
-                    }));
 
-                if char_count == max_depth {
+            if char_count == max_depth {
-                    buf += " ...";
+                buf += " ...";
-                }
+            }
 
-                buf
+            buf
-            };
+        };
 
         self.append_str(&buf);
         self.push_char('"');
     }
 
-    fn print_list_like(
+    fn print_list_like(&mut self, iter: &mut HCPreOrderIterator, addr: Addr, mut max_depth: usize) {
-        &mut self,
-        iter: &mut HCPreOrderIterator,
-        addr: Addr,
-        mut max_depth: usize,
-    ) {
         if self.check_max_depth(&mut max_depth) {
             iter.stack().pop();
             iter.stack().pop();
 
-            self.state_stack.push(TokenOrRedirect::Atom(clause_name!("...")));
+            self.state_stack
+                .push(TokenOrRedirect::Atom(clause_name!("...")));
             return;
         }
 
-        let mut heap_pstr_iter =
+        let mut heap_pstr_iter = self.machine_st.heap_pstr_iter(addr);
-            self.machine_st.heap_pstr_iter(addr);
 
         let buf = heap_pstr_iter.to_string();
 
@@ -1184,12 +1168,11 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
 
         let buf_len = buf.len();
 
-        let buf_iter: Box<dyn Iterator<Item=char>> =
+        let buf_iter: Box<dyn Iterator<Item = char>> = if self.max_depth == 0 {
-            if self.max_depth == 0 {
+            Box::new(buf.chars())
-                Box::new(buf.chars())
+        } else {
-            } else {
+            Box::new(buf.chars().take(max_depth))
-                Box::new(buf.chars().take(max_depth))
+        };
-            };
 
         let mut byte_len = 0;
 
@@ -1207,14 +1190,16 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
                 byte_len += c.len_utf8();
             }
 
-            for _ in 0 .. char_count {
+            for _ in 0..char_count {
                 self.state_stack.push(TokenOrRedirect::Close);
             }
 
             if self.max_depth > 0 && buf_len > byte_len {
-                self.state_stack.push(TokenOrRedirect::Atom(clause_name!("...")));
+                self.state_stack
+                    .push(TokenOrRedirect::Atom(clause_name!("...")));
             } else {
-                self.state_stack.push(TokenOrRedirect::FunctorRedirect(max_depth));
+                self.state_stack
+                    .push(TokenOrRedirect::FunctorRedirect(max_depth));
                 iter.stack().push(end_addr);
             }
         } else {
@@ -1232,15 +1217,17 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
                 byte_len += c.len_utf8();
             }
 
-            self.state_stack.push(TokenOrRedirect::CloseList(Rc::new(
+            self.state_stack
-                Cell::new((switch, 0))
+                .push(TokenOrRedirect::CloseList(Rc::new(Cell::new((switch, 0)))));
-            )));
 
             if self.max_depth > 0 && buf_len > byte_len {
-                self.state_stack.push(TokenOrRedirect::Atom(clause_name!("...")));
+                self.state_stack
-            }  else {
+                    .push(TokenOrRedirect::Atom(clause_name!("...")));
-                self.outputter.truncate(self.outputter.len() - ','.len_utf8());
+            } else {
-                self.state_stack.push(TokenOrRedirect::FunctorRedirect(max_depth));
+                self.outputter
+                    .truncate(self.outputter.len() - ','.len_utf8());
+                self.state_stack
+                    .push(TokenOrRedirect::FunctorRedirect(max_depth));
 
                 iter.stack().push(end_addr);
             }
@@ -1268,8 +1255,10 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
 
             let cell = Rc::new(Cell::new((true, 0)));
 
-            self.state_stack.push(TokenOrRedirect::CloseList(cell.clone()));
+            self.state_stack
-            self.state_stack.push(TokenOrRedirect::Atom(clause_name!("...")));
+                .push(TokenOrRedirect::CloseList(cell.clone()));
+            self.state_stack
+                .push(TokenOrRedirect::Atom(clause_name!("...")));
             self.state_stack.push(TokenOrRedirect::OpenList(cell));
 
             return;
@@ -1277,11 +1266,14 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
 
         let cell = Rc::new(Cell::new((true, max_depth)));
 
-        self.state_stack.push(TokenOrRedirect::CloseList(cell.clone()));
+        self.state_stack
+            .push(TokenOrRedirect::CloseList(cell.clone()));
 
-        self.state_stack.push(TokenOrRedirect::FunctorRedirect(max_depth));
+        self.state_stack
+            .push(TokenOrRedirect::FunctorRedirect(max_depth));
         self.state_stack.push(TokenOrRedirect::HeadTailSeparator); // bar
-        self.state_stack.push(TokenOrRedirect::FunctorRedirect(max_depth));
+        self.state_stack
+            .push(TokenOrRedirect::FunctorRedirect(max_depth));
 
         self.state_stack.push(TokenOrRedirect::OpenList(cell));
     }
@@ -1298,23 +1290,24 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
         max_depth: usize,
     ) {
         let add_brackets = if !self.ignore_ops {
-            negated_operand || if let Some(ref op) = op {
+            negated_operand
-                if self.numbervars && arity == 1 && name.as_str() == "$VAR" {
+                || if let Some(ref op) = op {
-                    !iter.immediate_leaf_has_property(|addr, heap| {
+                    if self.numbervars && arity == 1 && name.as_str() == "$VAR" {
-                        match heap.index_addr(&addr).as_ref() {
+                        !iter.immediate_leaf_has_property(|addr, heap| {
-                            &HeapCellValue::Integer(ref n) => &**n >= &0,
+                            match heap.index_addr(&addr).as_ref() {
-                            &HeapCellValue::Addr(Addr::Fixnum(n)) => n >= 0,
+                                &HeapCellValue::Integer(ref n) => &**n >= &0,
-                            &HeapCellValue::Addr(Addr::Float(f)) => f >= OrderedFloat(0f64),
+                                &HeapCellValue::Addr(Addr::Fixnum(n)) => n >= 0,
-                            &HeapCellValue::Rational(ref r) => &**r >= &0,
+                                &HeapCellValue::Addr(Addr::Float(f)) => f >= OrderedFloat(0f64),
-                            _ => false
+                                &HeapCellValue::Rational(ref r) => &**r >= &0,
-                        }
+                                _ => false,
-                    }) && needs_bracketing(&spec, op)
+                            }
+                        }) && needs_bracketing(&spec, op)
+                    } else {
+                        needs_bracketing(&spec, op)
+                    }
                 } else {
-                    needs_bracketing(&spec, op)
+                    is_functor_redirect && spec.prec() >= 1000
                 }
-            } else {
-                is_functor_redirect && spec.prec() >= 1000
-            }
         } else {
             false
         };
@@ -1344,15 +1337,15 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
         tcp_listener: &TcpListener,
         max_depth: usize,
     ) {
-        let (ip, port) =
+        let (ip, port) = if let Some(addr) = tcp_listener.local_addr().ok() {
-            if let Some(addr) = tcp_listener.local_addr().ok() {
+            (addr.ip(), Number::from(addr.port() as isize))
-                (addr.ip(), Number::from(addr.port() as isize))
+        } else {
-            } else {
+            let disconnected_atom = clause_name!("$disconnected_tcp_listener");
-                let disconnected_atom = clause_name!("$disconnected_tcp_listener");
+            self.state_stack
-                self.state_stack.push(TokenOrRedirect::Atom(disconnected_atom));
+                .push(TokenOrRedirect::Atom(disconnected_atom));
 
-                return;
+            return;
-            };
+        };
 
         if self.format_struct(iter, max_depth, 1, clause_name!("$tcp_listener")) {
             let atom = self.state_stack.pop().unwrap();
@@ -1369,22 +1362,16 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
         }
     }
 
-    fn print_stream(
+    fn print_stream(&mut self, iter: &mut HCPreOrderIterator, stream: &Stream, max_depth: usize) {
-        &mut self,
-        iter: &mut HCPreOrderIterator,
-        stream: &Stream,
-        max_depth: usize,
-    ) {
         if let Some(alias) = &stream.options.alias {
             self.print_atom(alias);
         } else {
             if self.format_struct(iter, max_depth, 1, clause_name!("$stream")) {
-                let atom =
+                let atom = if stream.is_stdout() || stream.is_stdin() {
-                    if stream.is_stdout() || stream.is_stdin() {
+                    TokenOrRedirect::Atom(clause_name!("user"))
-                        TokenOrRedirect::Atom(clause_name!("user"))
+                } else {
-                    } else {
+                    TokenOrRedirect::RawPtr(stream.as_ptr())
-                        TokenOrRedirect::RawPtr(stream.as_ptr())
+                };
-                    };
 
                 let stream_root = self.state_stack.pop().unwrap();
 
@@ -1414,7 +1401,8 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
 
         match self.machine_st.heap.index_addr(&addr).as_ref() {
             &HeapCellValue::NamedStr(arity, ref name, ref spec) => {
-                let spec = fetch_op_spec_from_existing(name.clone(), arity, spec.clone(), self.op_dir);
+                let spec =
+                    fetch_op_spec_from_existing(name.clone(), arity, spec.clone(), self.op_dir);
 
                 if let Some(spec) = spec {
                     self.handle_op_as_struct(

src/indexing.rs

@@ -1,11 +1,12 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
-use crate::prolog_parser_rebis::tabled_rc::*;
+use prolog_parser::clause_name;
+use prolog_parser::tabled_rc::*;
 
 use crate::forms::*;
 use crate::instructions::*;
 
-use crate::indexmap::IndexMap;
 use crate::rug::Integer;
+use indexmap::IndexMap;
 
 use slice_deque::{sdeq, SliceDeque};
 
@@ -43,14 +44,10 @@ impl OptArgIndexKey {
     #[inline]
     fn has_key_type(&self, key_type: OptArgIndexKeyType) -> bool {
         match (self, key_type) {
-            (OptArgIndexKey::Constant(..), OptArgIndexKeyType::Constant) |
+            (OptArgIndexKey::Constant(..), OptArgIndexKeyType::Constant)
-            (OptArgIndexKey::Structure(..), OptArgIndexKeyType::Structure) |
+            | (OptArgIndexKey::Structure(..), OptArgIndexKeyType::Structure)
-            (OptArgIndexKey::List(..), OptArgIndexKeyType::List) => {
+            | (OptArgIndexKey::List(..), OptArgIndexKeyType::List) => true,
-                true
+            _ => false,
-            }
-            _ => {
-                false
-            }
         }
     }
 }
@@ -93,16 +90,20 @@ impl<'a> IndexingCodeMergingPtr<'a> {
         indexing_code: &'a mut Vec<IndexingLine>,
         append_or_prepend: AppendOrPrepend,
     ) -> Self {
-        Self { skeleton, indexing_code, offset: 0, append_or_prepend }
+        Self {
+            skeleton,
+            indexing_code,
+            offset: 0,
+            append_or_prepend,
+        }
     }
 
-    fn internalize_constant(&mut self, constant_ptr: IndexingCodePtr)  {
+    fn internalize_constant(&mut self, constant_ptr: IndexingCodePtr) {
-        let constant_key =
+        let constant_key = search_skeleton_for_first_key_type(
-            search_skeleton_for_first_key_type(
+            self.skeleton,
-                self.skeleton,
+            OptArgIndexKeyType::Constant,
-                OptArgIndexKeyType::Constant,
+            self.append_or_prepend,
-                self.append_or_prepend,
+        );
-            );
 
         let mut constants = IndexMap::new();
 
@@ -117,7 +118,7 @@ impl<'a> IndexingCodeMergingPtr<'a> {
 
         if let IndexingCodePtr::Internal(_) = constant_ptr {
             self.indexing_code.push(IndexingLine::Indexing(
-                IndexingInstruction::SwitchOnConstant(constants)
+                IndexingInstruction::SwitchOnConstant(constants),
             ));
 
             let last_index = self.indexing_code.len() - 1;
@@ -126,34 +127,39 @@ impl<'a> IndexingCodeMergingPtr<'a> {
             self.offset = self.indexing_code.len();
 
             self.indexing_code.push(IndexingLine::Indexing(
-                IndexingInstruction::SwitchOnConstant(constants)
+                IndexingInstruction::SwitchOnConstant(constants),
             ));
         }
     }
 
-    fn add_indexed_choice_for_constant(&mut self, external: usize, constant: Constant, index: usize)
+    fn add_indexed_choice_for_constant(
-    {
+        &mut self,
-        let third_level_index =
+        external: usize,
-            if self.append_or_prepend.is_append() {
+        constant: Constant,
-                sdeq![
+        index: usize,
-                    IndexedChoiceInstruction::Try(external),
+    ) {
-                    IndexedChoiceInstruction::Trust(index)
+        let third_level_index = if self.append_or_prepend.is_append() {
-                ]
+            sdeq![
-            } else {
+                IndexedChoiceInstruction::Try(external),
-                sdeq![
+                IndexedChoiceInstruction::Trust(index)
-                    IndexedChoiceInstruction::Try(index),
+            ]
-                    IndexedChoiceInstruction::Trust(external)
+        } else {
-                ]
+            sdeq![
-            };
+                IndexedChoiceInstruction::Try(index),
+                IndexedChoiceInstruction::Trust(external)
+            ]
+        };
 
         let indexing_code_len = self.indexing_code.len();
-        self.indexing_code.push(IndexingLine::IndexedChoice(third_level_index));
+        self.indexing_code
+            .push(IndexingLine::IndexedChoice(third_level_index));
 
         match &mut self.indexing_code[self.offset] {
-            IndexingLine::Indexing(
+            IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(ref mut constants)) => {
-                IndexingInstruction::SwitchOnConstant(ref mut constants)
+                constants.insert(
-            ) => {
+                    constant,
-                constants.insert(constant, IndexingCodePtr::Internal(indexing_code_len - self.offset));
+                    IndexingCodePtr::Internal(indexing_code_len - self.offset),
+                );
             }
             _ => {
                 unreachable!()
@@ -164,10 +170,11 @@ impl<'a> IndexingCodeMergingPtr<'a> {
     fn extend_indexed_choice(&mut self, index: usize) {
         match &mut self.indexing_code[self.offset] {
             IndexingLine::IndexedChoice(ref mut indexed_choice_instrs)
-                if self.append_or_prepend.is_append() => {
+                if self.append_or_prepend.is_append() =>
-                    uncap_choice_seq_with_trust(indexed_choice_instrs);
+            {
-                    indexed_choice_instrs.push_back(IndexedChoiceInstruction::Trust(index));
+                uncap_choice_seq_with_trust(indexed_choice_instrs);
-                }
+                indexed_choice_instrs.push_back(IndexedChoiceInstruction::Trust(index));
+            }
             IndexingLine::IndexedChoice(ref mut indexed_choice_instrs) => {
                 uncap_choice_seq_with_try(indexed_choice_instrs);
                 indexed_choice_instrs.push_front(IndexedChoiceInstruction::Try(index));
@@ -188,9 +195,7 @@ impl<'a> IndexingCodeMergingPtr<'a> {
             let indexing_code_len = self.indexing_code.len();
 
             match &mut self.indexing_code[self.offset] {
-                IndexingLine::Indexing(
+                IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, ref mut c, ..)) => {
-                    IndexingInstruction::SwitchOnTerm(_, _, ref mut c, ..)
-                ) => {
                     match *c {
                         IndexingCodePtr::Fail => {
                             *c = IndexingCodePtr::External(index);
@@ -203,7 +208,7 @@ impl<'a> IndexingCodeMergingPtr<'a> {
                             *c = IndexingCodePtr::Internal(indexing_code_len);
 
                             self.indexing_code.push(IndexingLine::Indexing(
-                                IndexingInstruction::SwitchOnConstant(constants)
+                                IndexingInstruction::SwitchOnConstant(constants),
                             ));
 
                             self.offset = indexing_code_len;
@@ -213,12 +218,11 @@ impl<'a> IndexingCodeMergingPtr<'a> {
                         }
                     }
                 }
-                IndexingLine::Indexing(
+                IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(constants)) => {
-                    IndexingInstruction::SwitchOnConstant(constants)
-                ) => {
                     match constants.get(&overlapping_constant).cloned() {
                         None | Some(IndexingCodePtr::Fail) => {
-                            constants.insert(overlapping_constant, IndexingCodePtr::External(index));
+                            constants
+                                .insert(overlapping_constant, IndexingCodePtr::External(index));
                         }
                         Some(IndexingCodePtr::External(o)) => {
                             self.add_indexed_choice_for_constant(o, overlapping_constant, index);
@@ -232,9 +236,9 @@ impl<'a> IndexingCodeMergingPtr<'a> {
                     break;
                 }
                 IndexingLine::IndexedChoice(_) => {
-                    self.internalize_constant(
+                    self.internalize_constant(IndexingCodePtr::Internal(
-                        IndexingCodePtr::Internal(indexing_code_len - self.offset),
+                        indexing_code_len - self.offset,
-                    );
+                    ));
                 }
                 _ => {
                     unreachable!()
@@ -248,9 +252,7 @@ impl<'a> IndexingCodeMergingPtr<'a> {
             let indexing_code_len = self.indexing_code.len();
 
             match &mut self.indexing_code[self.offset] {
-                IndexingLine::Indexing(
+                IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, ref mut c, ..)) => {
-                    IndexingInstruction::SwitchOnTerm(_, _, ref mut c, ..)
-                ) => {
                     match *c {
                         IndexingCodePtr::Fail => {
                             *c = IndexingCodePtr::External(index);
@@ -265,9 +267,7 @@ impl<'a> IndexingCodeMergingPtr<'a> {
                         }
                     }
                 }
-                IndexingLine::Indexing(
+                IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(constants)) => {
-                    IndexingInstruction::SwitchOnConstant(constants)
-                ) => {
                     match constants.get(&constant).cloned() {
                         None | Some(IndexingCodePtr::Fail) => {
                             constants.insert(constant, IndexingCodePtr::External(index));
@@ -284,9 +284,9 @@ impl<'a> IndexingCodeMergingPtr<'a> {
                     break;
                 }
                 IndexingLine::IndexedChoice(_) => {
-                    self.internalize_constant(
+                    self.internalize_constant(IndexingCodePtr::Internal(
-                        IndexingCodePtr::Internal(indexing_code_len - self.offset),
+                        indexing_code_len - self.offset,
-                    );
+                    ));
                 }
                 _ => {
                     unreachable!()
@@ -295,13 +295,12 @@ impl<'a> IndexingCodeMergingPtr<'a> {
         }
     }
 
-    fn internalize_structure(&mut self, structure_ptr: IndexingCodePtr)  {
+    fn internalize_structure(&mut self, structure_ptr: IndexingCodePtr) {
-        let structure_key =
+        let structure_key = search_skeleton_for_first_key_type(
-            search_skeleton_for_first_key_type(
+            self.skeleton,
-                self.skeleton,
+            OptArgIndexKeyType::Structure,
-                OptArgIndexKeyType::Structure,
+            self.append_or_prepend,
-                self.append_or_prepend,
+        );
-            );
 
         let mut structures = IndexMap::new();
 
@@ -316,7 +315,7 @@ impl<'a> IndexingCodeMergingPtr<'a> {
 
         if let IndexingCodePtr::Internal(_) = structure_ptr {
             self.indexing_code.push(IndexingLine::Indexing(
-                IndexingInstruction::SwitchOnStructure(structures)
+                IndexingInstruction::SwitchOnStructure(structures),
             ));
 
             let last_index = self.indexing_code.len() - 1;
@@ -325,34 +324,39 @@ impl<'a> IndexingCodeMergingPtr<'a> {
             self.offset = self.indexing_code.len();
 
             self.indexing_code.push(IndexingLine::Indexing(
-                IndexingInstruction::SwitchOnStructure(structures)
+                IndexingInstruction::SwitchOnStructure(structures),
             ));
         }
     }
 
-    fn add_indexed_choice_for_structure(&mut self, external: usize, key: PredicateKey, index: usize)
+    fn add_indexed_choice_for_structure(
-    {
+        &mut self,
-        let third_level_index =
+        external: usize,
-            if self.append_or_prepend.is_append() {
+        key: PredicateKey,
-                sdeq![
+        index: usize,
-                    IndexedChoiceInstruction::Try(external),
+    ) {
-                    IndexedChoiceInstruction::Trust(index)
+        let third_level_index = if self.append_or_prepend.is_append() {
-                ]
+            sdeq![
-            } else {
+                IndexedChoiceInstruction::Try(external),
-                sdeq![
+                IndexedChoiceInstruction::Trust(index)
-                    IndexedChoiceInstruction::Try(index),
+            ]
-                    IndexedChoiceInstruction::Trust(external)
+        } else {
-                ]
+            sdeq![
-            };
+                IndexedChoiceInstruction::Try(index),
+                IndexedChoiceInstruction::Trust(external)
+            ]
+        };
 
         let indexing_code_len = self.indexing_code.len();
-        self.indexing_code.push(IndexingLine::IndexedChoice(third_level_index));
+        self.indexing_code
+            .push(IndexingLine::IndexedChoice(third_level_index));
 
         match &mut self.indexing_code[self.offset] {
-            IndexingLine::Indexing(
+            IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(ref mut structures)) => {
-                IndexingInstruction::SwitchOnStructure(ref mut structures)
+                structures.insert(
-            ) => {
+                    key,
-                structures.insert(key, IndexingCodePtr::Internal(indexing_code_len - self.offset));
+                    IndexingCodePtr::Internal(indexing_code_len - self.offset),
+                );
             }
             _ => {
                 unreachable!()
@@ -365,26 +369,26 @@ impl<'a> IndexingCodeMergingPtr<'a> {
             let indexing_code_len = self.indexing_code.len();
 
             match &mut self.indexing_code[self.offset] {
-                IndexingLine::Indexing(
+                IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(
-                    IndexingInstruction::SwitchOnTerm(_, _, _, _, ref mut s)
+                    _,
-                ) => {
+                    _,
-                    match *s {
+                    _,
-                        IndexingCodePtr::Fail => {
+                    _,
-                            *s = IndexingCodePtr::External(index);
+                    ref mut s,
-                            break;
+                )) => match *s {
-                        }
+                    IndexingCodePtr::Fail => {
-                        IndexingCodePtr::External(o) => {
+                        *s = IndexingCodePtr::External(index);
-                            *s = IndexingCodePtr::Internal(indexing_code_len - self.offset);
+                        break;
-                            self.internalize_structure(IndexingCodePtr::External(o));
-                        }
-                        IndexingCodePtr::Internal(o) => {
-                            self.offset += o;
-                        }
                     }
-                }
+                    IndexingCodePtr::External(o) => {
-                IndexingLine::Indexing(
+                        *s = IndexingCodePtr::Internal(indexing_code_len - self.offset);
-                    IndexingInstruction::SwitchOnStructure(structures)
+                        self.internalize_structure(IndexingCodePtr::External(o));
-                ) => {
+                    }
+                    IndexingCodePtr::Internal(o) => {
+                        self.offset += o;
+                    }
+                },
+                IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(structures)) => {
                     match structures.get(&key).cloned() {
                         None | Some(IndexingCodePtr::Fail) => {
                             structures.insert(key, IndexingCodePtr::External(index));
@@ -404,9 +408,9 @@ impl<'a> IndexingCodeMergingPtr<'a> {
                     // replace this value, at self.offset, with
                     // SwitchOnStructures, and swap this IndexedChoice
                     // vector to the end of self.indexing_code.
-                    self.internalize_structure(
+                    self.internalize_structure(IndexingCodePtr::Internal(
-                        IndexingCodePtr::Internal(indexing_code_len - self.offset),
+                        indexing_code_len - self.offset,
-                    );
+                    ));
                 }
                 _ => {
                     unreachable!()
@@ -419,9 +423,7 @@ impl<'a> IndexingCodeMergingPtr<'a> {
         let indexing_code_len = self.indexing_code.len();
 
         match &mut self.indexing_code[self.offset] {
-            IndexingLine::Indexing(
+            IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, _, ref mut l, _)) => {
-                IndexingInstruction::SwitchOnTerm(_, _, _, ref mut l, _)
-            ) => {
                 match *l {
                     IndexingCodePtr::Fail => {
                         *l = IndexingCodePtr::External(index);
@@ -429,22 +431,20 @@ impl<'a> IndexingCodeMergingPtr<'a> {
                     IndexingCodePtr::External(o) => {
                         *l = IndexingCodePtr::Internal(indexing_code_len - self.offset);
 
-                        let third_level_index =
+                        let third_level_index = if self.append_or_prepend.is_append() {
-                            if self.append_or_prepend.is_append() {
+                            sdeq![
-                                sdeq![
+                                IndexedChoiceInstruction::Try(o),
-                                    IndexedChoiceInstruction::Try(o),
+                                IndexedChoiceInstruction::Trust(index)
-                                    IndexedChoiceInstruction::Trust(index)
+                            ]
-                                ]
+                        } else {
-                            } else {
+                            sdeq![
-                                sdeq![
+                                IndexedChoiceInstruction::Try(index),
-                                    IndexedChoiceInstruction::Try(index),
+                                IndexedChoiceInstruction::Trust(o)
-                                    IndexedChoiceInstruction::Trust(o)
+                            ]
-                                ]
+                        };
-                            };
 
-                        self.indexing_code.push(
+                        self.indexing_code
-                            IndexingLine::IndexedChoice(third_level_index),
+                            .push(IndexingLine::IndexedChoice(third_level_index));
-                        );
                     }
                     IndexingCodePtr::Internal(o) => {
                         self.offset += o;
@@ -462,24 +462,16 @@ impl<'a> IndexingCodeMergingPtr<'a> {
 pub fn merge_clause_index(
     target_indexing_code: &mut Vec<IndexingLine>,
     skeleton: &mut [ClauseIndexInfo], // the clause to be merged is the last element in the skeleton.
-    new_clause_loc: usize, // the absolute location of the new clause in the code vector.
+    new_clause_loc: usize,            // the absolute location of the new clause in the code vector.
     append_or_prepend: AppendOrPrepend,
 ) {
-    let opt_arg_index_key =
+    let opt_arg_index_key = match append_or_prepend {
-        match append_or_prepend {
+        AppendOrPrepend::Append => skeleton.last_mut().unwrap().opt_arg_index_key.take(),
-            AppendOrPrepend::Append => {
+        AppendOrPrepend::Prepend => skeleton.first_mut().unwrap().opt_arg_index_key.take(),
-                skeleton.last_mut().unwrap().opt_arg_index_key.take()
+    };
-            }
-            AppendOrPrepend::Prepend => {
-                skeleton.first_mut().unwrap().opt_arg_index_key.take()
-            }
-        };
 
-    let mut merging_ptr = IndexingCodeMergingPtr::new(
+    let mut merging_ptr =
-        skeleton,
+        IndexingCodeMergingPtr::new(skeleton, target_indexing_code, append_or_prepend);
-        target_indexing_code,
-        append_or_prepend,
-    );
 
     match &opt_arg_index_key {
         OptArgIndexKey::Constant(_, index_loc, ref constant, ref overlapping_constants) => {
@@ -488,7 +480,9 @@ pub fn merge_clause_index(
 
             for overlapping_constant in overlapping_constants {
                 merging_ptr.index_overlapping_constant(
-                    constant, overlapping_constant.clone(), offset,
+                    constant,
+                    overlapping_constant.clone(),
+                    offset,
                 );
             }
         }
@@ -514,10 +508,7 @@ pub fn merge_clause_index(
 }
 
 #[inline]
-fn remove_instruction_with_offset(
+fn remove_instruction_with_offset(code: &mut SliceDeque<IndexedChoiceInstruction>, offset: usize) {
-    code: &mut SliceDeque<IndexedChoiceInstruction>,
-    offset: usize,
-) {
     for (index, line) in code.iter().enumerate() {
         if offset == line.offset() {
             code.remove(index);
@@ -537,9 +528,7 @@ pub fn remove_constant_indices(
     let iter = once(constant).chain(overlapping_constants.iter());
 
     match &mut indexing_code[index] {
-        IndexingLine::Indexing(
+        IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, ref mut c, ..)) => {
-            IndexingInstruction::SwitchOnTerm(_, _, ref mut c, ..)
-        ) => {
             match *c {
                 IndexingCodePtr::External(_) => {
                     *c = IndexingCodePtr::Fail;
@@ -560,12 +549,13 @@ pub fn remove_constant_indices(
 
     let mut constants_index = 0;
 
-    for constant in iter { // (constant, index_loc) in iter.zip(index_locs.iter()) {
+    for constant in iter {
+        // (constant, index_loc) in iter.zip(index_locs.iter()) {
         loop {
             match &mut indexing_code[index] {
-                IndexingLine::Indexing(
+                IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(
-                    IndexingInstruction::SwitchOnConstant(ref mut constants)
+                    ref mut constants,
-                ) => {
+                )) => {
                     constants_index = index;
 
                     match constants.get(constant).cloned() {
@@ -586,18 +576,21 @@ pub fn remove_constant_indices(
 
                     if indexed_choice_instrs.len() == 1 {
                         let ext = IndexingCodePtr::External(
-                            indexed_choice_instrs.pop_back().unwrap().offset()
+                            indexed_choice_instrs.pop_back().unwrap().offset(),
                         );
 
                         match &mut indexing_code[constants_index] {
-                            IndexingLine::Indexing(
+                            IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(
-                                IndexingInstruction::SwitchOnTerm(_, _, ref mut c, ..)
+                                _,
-                            ) => {
+                                _,
+                                ref mut c,
+                                ..,
+                            )) => {
                                 *c = ext;
                             }
-                            IndexingLine::Indexing(
+                            IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(
-                                IndexingInstruction::SwitchOnConstant(ref mut constants)
+                                ref mut constants,
-                            ) => {
+                            )) => {
                                 constants.insert(constant.clone(), ext);
                             }
                             _ => {
@@ -616,13 +609,11 @@ pub fn remove_constant_indices(
     }
 
     match &indexing_code[constants_index] {
-        IndexingLine::Indexing(
+        IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(ref constants))
-            IndexingInstruction::SwitchOnConstant(ref constants)
+            if constants.is_empty() =>
-        ) if constants.is_empty() => {
+        {
             match &mut indexing_code[0] {
-                IndexingLine::Indexing(
+                IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, ref mut c, ..)) => {
-                    IndexingInstruction::SwitchOnTerm(_, _, ref mut c, ..)
-                ) => {
                     *c = IndexingCodePtr::Fail;
                 }
                 _ => {
@@ -630,8 +621,7 @@ pub fn remove_constant_indices(
                 }
             }
         }
-        _ => {
+        _ => {}
-        }
     }
 }
 
@@ -644,9 +634,7 @@ pub fn remove_structure_index(
     let mut index = 0;
 
     match &mut indexing_code[index] {
-        IndexingLine::Indexing(
+        IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, _, _, ref mut s)) => {
-            IndexingInstruction::SwitchOnTerm(_, _, _, _, ref mut s)
-        ) => {
             match *s {
                 IndexingCodePtr::External(_) => {
                     *s = IndexingCodePtr::Fail;
@@ -669,9 +657,7 @@ pub fn remove_structure_index(
 
     loop {
         match &mut indexing_code[index] {
-            IndexingLine::Indexing(
+            IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(ref mut structures)) => {
-                IndexingInstruction::SwitchOnStructure(ref mut structures)
-            ) => {
                 structures_index = index;
 
                 match structures.get(&(name.clone(), arity)).cloned() {
@@ -692,18 +678,22 @@ pub fn remove_structure_index(
 
                 if indexed_choice_instrs.len() == 1 {
                     let ext = IndexingCodePtr::External(
-                        indexed_choice_instrs.pop_back().unwrap().offset()
+                        indexed_choice_instrs.pop_back().unwrap().offset(),
                     );
 
                     match &mut indexing_code[structures_index] {
-                        IndexingLine::Indexing(
+                        IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(
-                            IndexingInstruction::SwitchOnTerm(_, _, _, _, ref mut s)
+                            _,
-                        ) => {
+                            _,
+                            _,
+                            _,
+                            ref mut s,
+                        )) => {
                             *s = ext;
                         }
-                        IndexingLine::Indexing(
+                        IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(
-                            IndexingInstruction::SwitchOnStructure(ref mut structures)
+                            ref mut structures,
-                        ) => {
+                        )) => {
                             structures.insert((name.clone(), arity), ext);
                         }
                         _ => {
@@ -721,13 +711,17 @@ pub fn remove_structure_index(
     }
 
     match &indexing_code[structures_index] {
-        IndexingLine::Indexing(
+        IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(ref structures))
-            IndexingInstruction::SwitchOnStructure(ref structures)
+            if structures.is_empty() =>
-        ) if structures.is_empty() => {
+        {
             match &mut indexing_code[0] {
-                IndexingLine::Indexing(
+                IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(
-                    IndexingInstruction::SwitchOnTerm(_, _, _, _, ref mut s)
+                    _,
-                ) => {
+                    _,
+                    _,
+                    _,
+                    ref mut s,
+                )) => {
                     *s = IndexingCodePtr::Fail;
                 }
                 _ => {
@@ -735,21 +729,15 @@ pub fn remove_structure_index(
                 }
             }
         }
-        _ => {
+        _ => {}
-        }
     }
 }
 
-pub fn remove_list_index(
+pub fn remove_list_index(indexing_code: &mut Vec<IndexingLine>, offset: usize) {
-    indexing_code: &mut Vec<IndexingLine>,
-    offset: usize,
-) {
     let mut index = 0;
 
     match &mut indexing_code[index] {
-        IndexingLine::Indexing(
+        IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, _, ref mut l, _)) => {
-            IndexingInstruction::SwitchOnTerm(_, _, _, ref mut l, _)
-        ) => {
             match *l {
                 IndexingCodePtr::External(_) => {
                     *l = IndexingCodePtr::Fail;
@@ -773,14 +761,17 @@ pub fn remove_list_index(
             remove_instruction_with_offset(indexed_choice_instrs, offset);
 
             if indexed_choice_instrs.len() == 1 {
-                let ext = IndexingCodePtr::External(
+                let ext =
-                    indexed_choice_instrs.pop_back().unwrap().offset()
+                    IndexingCodePtr::External(indexed_choice_instrs.pop_back().unwrap().offset());
-                );
 
                 match &mut indexing_code[0] {
-                    IndexingLine::Indexing(
+                    IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(
-                        IndexingInstruction::SwitchOnTerm(_, _, _, ref mut l, _)
+                        _,
-                    ) => {
+                        _,
+                        _,
+                        ref mut l,
+                        _,
+                    )) => {
                         *l = ext;
                     }
                     _ => {
@@ -836,8 +827,7 @@ pub fn remove_index(
 fn second_level_index<IndexKey: Eq + Hash>(
     indices: IndexMap<IndexKey, SliceDeque<IndexedChoiceInstruction>>,
     prelude: &mut SliceDeque<IndexingLine>,
-) -> IndexMap<IndexKey, IndexingCodePtr>
+) -> IndexMap<IndexKey, IndexingCodePtr> {
-{
     let mut index_locs = IndexMap::new();
 
     for (key, mut code) in indices.into_iter() {
@@ -868,10 +858,11 @@ fn switch_on<IndexKey: Eq + Hash>(
 
         IndexingCodePtr::Internal(1)
     } else {
-        index.into_iter()
+        index
-             .next()
+            .into_iter()
-             .map(|(_, v)| v)
+            .next()
-             .unwrap_or(IndexingCodePtr::Fail)
+            .map(|(_, v)| v)
+            .unwrap_or(IndexingCodePtr::Fail)
     }
 }
 
@@ -884,9 +875,10 @@ fn switch_on_list(
         prelude.push_back(IndexingLine::from(lists));
         IndexingCodePtr::Internal(1)
     } else {
-        lists.first()
+        lists
-             .map(|i| IndexingCodePtr::External(i.offset()))
+            .first()
-             .unwrap_or(IndexingCodePtr::Fail)
+            .map(|i| IndexingCodePtr::External(i.offset()))
+            .unwrap_or(IndexingCodePtr::Fail)
     }
 }
 
@@ -978,8 +970,7 @@ pub fn constant_key_alternatives(constant: &Constant, atom_tbl: TabledData<Atom>
                 constants.push(Constant::Fixnum(n));
             }
         }
-        _ => {
+        _ => {}
-        }
     }
 
     constants
@@ -1001,7 +992,7 @@ impl CodeOffsets {
             constants: IndexMap::new(),
             lists: sdeq![],
             structures: IndexMap::new(),
-            optimal_index
+            optimal_index,
         }
     }
 
@@ -1011,20 +1002,15 @@ impl CodeOffsets {
     }
 
     fn index_constant(&mut self, constant: &Constant, index: usize) -> Vec<Constant> {
-        let overlapping_constants =
+        let overlapping_constants = constant_key_alternatives(constant, self.atom_tbl.clone());
-            constant_key_alternatives(constant, self.atom_tbl.clone());
 
-        let code = self.constants
+        let code = self.constants.entry(constant.clone()).or_insert(sdeq![]);
-            .entry(constant.clone())
-            .or_insert(sdeq![]);
 
         let is_initial_index = code.is_empty();
         code.push_back(compute_index(is_initial_index, index));
 
         for constant in &overlapping_constants {
-            let code = self.constants
+            let code = self.constants.entry(constant.clone()).or_insert(sdeq![]);
-                .entry(constant.clone())
-                .or_insert(sdeq![]);
 
             let is_initial_index = code.is_empty();
             let index = compute_index(is_initial_index, index);
@@ -1062,25 +1048,21 @@ impl CodeOffsets {
                 self.index_structure(name, terms.len(), index);
             }
             &Term::Cons(..) | &Term::Constant(_, Constant::String(_)) => {
-                clause_index_info.opt_arg_index_key =
+                clause_index_info.opt_arg_index_key = OptArgIndexKey::List(self.optimal_index, 0);
-                    OptArgIndexKey::List(self.optimal_index, 0);
 
                 self.index_list(index);
             }
             &Term::Constant(_, ref constant) => {
-                let overlapping_constants =
+                let overlapping_constants = self.index_constant(constant, index);
-                    self.index_constant(constant, index);
 
-                clause_index_info.opt_arg_index_key =
+                clause_index_info.opt_arg_index_key = OptArgIndexKey::Constant(
-                    OptArgIndexKey::Constant(
+                    self.optimal_index,
-                        self.optimal_index,
+                    0,
-                        0,
+                    constant.clone(),
-                        constant.clone(),
+                    overlapping_constants,
-                        overlapping_constants,
+                );
-                    );
-            }
-            _ => {
             }
+            _ => {}
         }
     }
 
@@ -1117,8 +1099,7 @@ impl CodeOffsets {
             IndexingCodePtr::Internal(ref mut i) => {
                 *i += con_loc.is_internal() as usize;
             }
-            _ => {
+            _ => {}
-            }
         };
 
         match &mut lst_loc {
@@ -1126,15 +1107,18 @@ impl CodeOffsets {
                 *i += con_loc.is_internal() as usize;
                 *i += str_loc.is_internal() as usize;
             }
-            _ => {
+            _ => {}
-            }
         };
 
         let var_offset = 1 + skip_stub_try_me_else as usize;
 
-        prelude.push_front(IndexingLine::from(
+        prelude.push_front(IndexingLine::from(IndexingInstruction::SwitchOnTerm(
-            IndexingInstruction::SwitchOnTerm(self.optimal_index, var_offset, con_loc, lst_loc, str_loc)
+            self.optimal_index,
-        ));
+            var_offset,
+            con_loc,
+            lst_loc,
+            str_loc,
+        )));
 
         prelude.into_iter().collect()
     }

src/instructions.rs

@@ -1,4 +1,5 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
+use prolog_parser::clause_name;
 
 use crate::clause_types::*;
 use crate::forms::*;
@@ -8,7 +9,7 @@ use crate::machine::machine_errors::MachineStub;
 use crate::machine::machine_indices::*;
 use crate::rug::Integer;
 
-use crate::indexmap::IndexMap;
+use indexmap::IndexMap;
 
 use slice_deque::SliceDeque;
 
@@ -34,9 +35,7 @@ impl Level {
 impl ArithmeticTerm {
     fn into_functor(&self) -> MachineStub {
         match self {
-            &ArithmeticTerm::Reg(r) => {
+            &ArithmeticTerm::Reg(r) => reg_type_into_functor(r),
-                reg_type_into_functor(r)
-            }
             &ArithmeticTerm::Interm(i) => {
                 functor!("intermediate", [integer(i)])
             }
@@ -185,16 +184,11 @@ impl Line {
 
     pub fn enqueue_functors(&self, mut h: usize, functors: &mut Vec<MachineStub>) {
         match self {
-            &Line::Arithmetic(ref arith_instr) =>
+            &Line::Arithmetic(ref arith_instr) => functors.push(arith_instr.to_functor(h)),
-                functors.push(arith_instr.to_functor(h)),
+            &Line::Choice(ref choice_instr) => functors.push(choice_instr.to_functor()),
-            &Line::Choice(ref choice_instr) =>
+            &Line::Control(ref control_instr) => functors.push(control_instr.to_functor()),
-                functors.push(choice_instr.to_functor()),
+            &Line::Cut(ref cut_instr) => functors.push(cut_instr.to_functor(h)),
-            &Line::Control(ref control_instr) =>
+            &Line::Fact(ref fact_instr) => functors.push(fact_instr.to_functor(h)),
-                functors.push(control_instr.to_functor()),
-            &Line::Cut(ref cut_instr) =>
-                functors.push(cut_instr.to_functor(h)),
-            &Line::Fact(ref fact_instr) =>
-                functors.push(fact_instr.to_functor(h)),
             &Line::IndexingCode(ref indexing_instrs) => {
                 for indexing_instr in indexing_instrs {
                     match indexing_instr {
@@ -213,10 +207,10 @@ impl Line {
                     }
                 }
             }
-            &Line::IndexedChoice(ref indexed_choice_instr) =>
+            &Line::IndexedChoice(ref indexed_choice_instr) => {
-                functors.push(indexed_choice_instr.to_functor()),
+                functors.push(indexed_choice_instr.to_functor())
-            &Line::Query(ref query_instr) =>
+            }
-                functors.push(query_instr.to_functor(h)),
+            &Line::Query(ref query_instr) => functors.push(query_instr.to_functor(h)),
         }
     }
 }
@@ -224,24 +218,16 @@ impl Line {
 #[inline]
 pub fn to_indexing_line_mut(line: &mut Line) -> Option<&mut Vec<IndexingLine>> {
     match line {
-        Line::IndexingCode(ref mut indexing_code) => {
+        Line::IndexingCode(ref mut indexing_code) => Some(indexing_code),
-            Some(indexing_code)
+        _ => None,
-        }
-        _ => {
-            None
-        }
     }
 }
 
 #[inline]
 pub fn to_indexing_line(line: &Line) -> Option<&Vec<IndexingLine>> {
     match line {
-        Line::IndexingCode(ref indexing_code) => {
+        Line::IndexingCode(ref indexing_code) => Some(indexing_code),
-            Some(indexing_code)
+        _ => None,
-        }
-        _ => {
-            None
-        }
     }
 }
 
@@ -296,11 +282,7 @@ fn arith_instr_unary_functor(
 ) -> MachineStub {
     let at_stub = at.into_functor();
 
-    functor!(
+    functor!(name, [aux(h, 0), integer(t)], [at_stub])
-        name,
-        [aux(h, 0), integer(t)],
-        [at_stub]
-    )
 }
 
 fn arith_instr_bin_functor(
@@ -383,39 +365,17 @@ impl ArithmeticInstruction {
             &ArithmeticInstruction::Gcd(ref at_1, ref at_2, t) => {
                 arith_instr_bin_functor(h, "gcd", at_1, at_2, t)
             }
-            &ArithmeticInstruction::Sign(ref at, t) => {
+            &ArithmeticInstruction::Sign(ref at, t) => arith_instr_unary_functor(h, "sign", at, t),
-                arith_instr_unary_functor(h, "sign", at, t)
+            &ArithmeticInstruction::Cos(ref at, t) => arith_instr_unary_functor(h, "cos", at, t),
-            }
+            &ArithmeticInstruction::Sin(ref at, t) => arith_instr_unary_functor(h, "sin", at, t),
-            &ArithmeticInstruction::Cos(ref at, t)  => {
+            &ArithmeticInstruction::Tan(ref at, t) => arith_instr_unary_functor(h, "tan", at, t),
-                arith_instr_unary_functor(h, "cos", at, t)
+            &ArithmeticInstruction::Log(ref at, t) => arith_instr_unary_functor(h, "log", at, t),
-            }
+            &ArithmeticInstruction::Exp(ref at, t) => arith_instr_unary_functor(h, "exp", at, t),
-            &ArithmeticInstruction::Sin(ref at, t)  => {
+            &ArithmeticInstruction::ACos(ref at, t) => arith_instr_unary_functor(h, "acos", at, t),
-                arith_instr_unary_functor(h, "sin", at, t)
+            &ArithmeticInstruction::ASin(ref at, t) => arith_instr_unary_functor(h, "asin", at, t),
-            }
+            &ArithmeticInstruction::ATan(ref at, t) => arith_instr_unary_functor(h, "atan", at, t),
-            &ArithmeticInstruction::Tan(ref at, t)  => {
+            &ArithmeticInstruction::Sqrt(ref at, t) => arith_instr_unary_functor(h, "sqrt", at, t),
-                arith_instr_unary_functor(h, "tan", at, t)
+            &ArithmeticInstruction::Abs(ref at, t) => arith_instr_unary_functor(h, "abs", at, t),
-            }
-            &ArithmeticInstruction::Log(ref at, t)  => {
-                arith_instr_unary_functor(h, "log", at, t)
-            }
-            &ArithmeticInstruction::Exp(ref at, t)  => {
-                arith_instr_unary_functor(h, "exp", at, t)
-            }
-            &ArithmeticInstruction::ACos(ref at, t) => {
-                arith_instr_unary_functor(h, "acos", at, t)
-            }
-            &ArithmeticInstruction::ASin(ref at, t) => {
-                arith_instr_unary_functor(h, "asin", at, t)
-            }
-            &ArithmeticInstruction::ATan(ref at, t) => {
-                arith_instr_unary_functor(h, "atan", at, t)
-            }
-            &ArithmeticInstruction::Sqrt(ref at, t) => {
-                arith_instr_unary_functor(h, "sqrt", at, t)
-            }
-            &ArithmeticInstruction::Abs(ref at, t) => {
-                arith_instr_unary_functor(h, "abs", at, t)
-            }
             &ArithmeticInstruction::Float(ref at, t) => {
                 arith_instr_unary_functor(h, "float", at, t)
             }
@@ -431,12 +391,8 @@ impl ArithmeticInstruction {
             &ArithmeticInstruction::Floor(ref at, t) => {
                 arith_instr_unary_functor(h, "floor", at, t)
             }
-            &ArithmeticInstruction::Neg(ref at, t) => {
+            &ArithmeticInstruction::Neg(ref at, t) => arith_instr_unary_functor(h, "-", at, t),
-                arith_instr_unary_functor(h, "-", at, t)
+            &ArithmeticInstruction::Plus(ref at, t) => arith_instr_unary_functor(h, "+", at, t),
-            }
-            &ArithmeticInstruction::Plus(ref at, t) => {
-                arith_instr_unary_functor(h, "+", at, t)
-            }
             &ArithmeticInstruction::BitwiseComplement(ref at, t) => {
                 arith_instr_unary_functor(h, "\\", at, t)
             }
@@ -451,21 +407,18 @@ pub enum ControlInstruction {
     CallClause(ClauseType, usize, usize, bool, bool),
     Deallocate,
     JmpBy(usize, usize, usize, bool), // arity, global_offset, perm_vars after threshold, last call.
-    RevJmpBy(usize), // notice the lack of context change as in
+    RevJmpBy(usize),                  // notice the lack of context change as in
-                     // JmpBy. RevJmpBy is used only to patch extensible
+    // JmpBy. RevJmpBy is used only to patch extensible
-                     // predicates together.
+    // predicates together.
     Proceed,
 }
 
 impl ControlInstruction {
     pub fn perm_vars(&self) -> Option<usize> {
         match self {
-            ControlInstruction::CallClause(_, _, num_cells, ..) =>
+            ControlInstruction::CallClause(_, _, num_cells, ..) => Some(*num_cells),
-                Some(*num_cells),
+            ControlInstruction::JmpBy(_, _, num_cells, ..) => Some(*num_cells),
-            ControlInstruction::JmpBy(_, _, num_cells, ..) =>
+            _ => None,
-                Some(*num_cells),
-            _ =>
-                None
         }
     }
 
@@ -500,7 +453,13 @@ impl ControlInstruction {
 #[derive(Debug)]
 pub enum IndexingInstruction {
     // The first index is the optimal argument being indexed.
-    SwitchOnTerm(usize, usize, IndexingCodePtr, IndexingCodePtr, IndexingCodePtr),
+    SwitchOnTerm(
+        usize,
+        usize,
+        IndexingCodePtr,
+        IndexingCodePtr,
+        IndexingCodePtr,
+    ),
     SwitchOnConstant(IndexMap<Constant, IndexingCodePtr>),
     SwitchOnStructure(IndexMap<(ClauseName, usize), IndexingCodePtr>),
 }
@@ -511,11 +470,13 @@ impl IndexingInstruction {
             &IndexingInstruction::SwitchOnTerm(arg, vars, constants, lists, structures) => {
                 functor!(
                     "switch_on_term",
-                    [integer(arg),
+                    [
-                     integer(vars),
+                        integer(arg),
-                     indexing_code_ptr(h, constants),
+                        integer(vars),
-                     indexing_code_ptr(h, lists),
+                        indexing_code_ptr(h, constants),
-                     indexing_code_ptr(h, structures)]
+                        indexing_code_ptr(h, lists),
+                        indexing_code_ptr(h, structures)
+                    ]
                 )
             }
             &IndexingInstruction::SwitchOnConstant(ref constants) => {
@@ -528,15 +489,14 @@ impl IndexingInstruction {
                     let key_value_pair = functor!(
                         ":",
                         SharedOpDesc::new(600, XFY),
-                        [constant(c),
+                        [constant(c), indexing_code_ptr(h + 3, *ptr)]
-                         indexing_code_ptr(h + 3, *ptr)]
                     );
 
                     key_value_list_stub.push(HeapCellValue::Addr(Addr::Lis(h + 1)));
                     key_value_list_stub.push(HeapCellValue::Addr(Addr::Str(h + 3)));
-                    key_value_list_stub.push(HeapCellValue::Addr(
+                    key_value_list_stub.push(HeapCellValue::Addr(Addr::HeapCell(
-                        Addr::HeapCell(h + 3 + key_value_pair.len())
+                        h + 3 + key_value_pair.len(),
-                    ));
+                    )));
 
                     h += key_value_pair.len() + 3;
                     key_value_list_stub.extend(key_value_pair.into_iter());
@@ -560,23 +520,21 @@ impl IndexingInstruction {
                     let predicate_indicator_stub = functor!(
                         "/",
                         SharedOpDesc::new(400, YFX),
-                        [clause_name(name.clone()),
+                        [clause_name(name.clone()), integer(*arity)]
-                         integer(*arity)]
                     );
 
                     let key_value_pair = functor!(
                         ":",
                         SharedOpDesc::new(600, XFY),
-                        [aux(h + 3, 0),
+                        [aux(h + 3, 0), indexing_code_ptr(h + 3, *ptr)],
-                         indexing_code_ptr(h + 3, *ptr)],
                         [predicate_indicator_stub]
                     );
 
                     key_value_list_stub.push(HeapCellValue::Addr(Addr::Lis(h + 1)));
                     key_value_list_stub.push(HeapCellValue::Addr(Addr::Str(h + 3)));
-                    key_value_list_stub.push(HeapCellValue::Addr(
+                    key_value_list_stub.push(HeapCellValue::Addr(Addr::HeapCell(
-                        Addr::HeapCell(h + 3 + key_value_pair.len())
+                        h + 3 + key_value_pair.len(),
-                    ));
+                    )));
 
                     h += key_value_pair.len() + 3;
                     key_value_list_stub.extend(key_value_pair.into_iter());
@@ -614,7 +572,7 @@ impl FactInstruction {
         match self {
             &FactInstruction::GetConstant(lvl, ref c, r) => {
                 let lvl_stub = lvl.into_functor();
-                let rt_stub  = reg_type_into_functor(r);
+                let rt_stub = reg_type_into_functor(r);
 
                 functor!(
                     "get_constant",
@@ -624,17 +582,13 @@ impl FactInstruction {
             }
             &FactInstruction::GetList(lvl, r) => {
                 let lvl_stub = lvl.into_functor();
-                let rt_stub  = reg_type_into_functor(r);
+                let rt_stub = reg_type_into_functor(r);
 
-                functor!(
+                functor!("get_list", [aux(h, 0), aux(h, 1)], [lvl_stub, rt_stub])
-                    "get_list",
-                    [aux(h, 0), aux(h, 1)],
-                    [lvl_stub, rt_stub]
-                )
             }
             &FactInstruction::GetPartialString(lvl, ref s, r, has_tail) => {
                 let lvl_stub = lvl.into_functor();
-                let rt_stub  = reg_type_into_functor(r);
+                let rt_stub = reg_type_into_functor(r);
 
                 functor!(
                     "get_partial_string",
@@ -654,20 +608,12 @@ impl FactInstruction {
             &FactInstruction::GetValue(r, arg) => {
                 let rt_stub = reg_type_into_functor(r);
 
-                functor!(
+                functor!("get_value", [aux(h, 0), integer(arg)], [rt_stub])
-                    "get_value",
-                    [aux(h, 0), integer(arg)],
-                    [rt_stub]
-                )
             }
             &FactInstruction::GetVariable(r, arg) => {
                 let rt_stub = reg_type_into_functor(r);
 
-                functor!(
+                functor!("get_variable", [aux(h, 0), integer(arg)], [rt_stub])
-                    "get_variable",
-                    [aux(h, 0), integer(arg)],
-                    [rt_stub]
-                )
             }
             &FactInstruction::UnifyConstant(ref c) => {
                 functor!("unify_constant", [constant(h, c)], [])
@@ -675,29 +621,17 @@ impl FactInstruction {
             &FactInstruction::UnifyLocalValue(r) => {
                 let rt_stub = reg_type_into_functor(r);
 
-                functor!(
+                functor!("unify_local_value", [aux(h, 0)], [rt_stub])
-                    "unify_local_value",
-                    [aux(h, 0)],
-                    [rt_stub]
-                )
             }
             &FactInstruction::UnifyVariable(r) => {
                 let rt_stub = reg_type_into_functor(r);
 
-                functor!(
+                functor!("unify_variable", [aux(h, 0)], [rt_stub])
-                    "unify_variable",
-                    [aux(h, 0)],
-                    [rt_stub]
-                )
             }
             &FactInstruction::UnifyValue(r) => {
                 let rt_stub = reg_type_into_functor(r);
 
-                functor!(
+                functor!("unify_value", [aux(h, 0)], [rt_stub])
-                    "unify_value",
-                    [aux(h, 0)],
-                    [rt_stub]
-                )
             }
             &FactInstruction::UnifyVoid(vars) => {
                 functor!("unify_void", [integer(vars)])
@@ -726,13 +660,12 @@ pub enum QueryInstruction {
 impl QueryInstruction {
     pub fn to_functor(&self, h: usize) -> MachineStub {
         match self {
-            &QueryInstruction::PutUnsafeValue(norm, arg) => functor!(
+            &QueryInstruction::PutUnsafeValue(norm, arg) => {
-                "put_unsafe_value",
+                functor!("put_unsafe_value", [integer(norm), integer(arg)])
-                [integer(norm), integer(arg)]
+            }
-            ),
             &QueryInstruction::PutConstant(lvl, ref c, r) => {
                 let lvl_stub = lvl.into_functor();
-                let rt_stub  = reg_type_into_functor(r);
+                let rt_stub = reg_type_into_functor(r);
 
                 functor!(
                     "put_constant",
@@ -742,17 +675,13 @@ impl QueryInstruction {
             }
             &QueryInstruction::PutList(lvl, r) => {
                 let lvl_stub = lvl.into_functor();
-                let rt_stub  = reg_type_into_functor(r);
+                let rt_stub = reg_type_into_functor(r);
 
-                functor!(
+                functor!("put_list", [aux(h, 0), aux(h, 1)], [lvl_stub, rt_stub])
-                    "put_list",
-                    [aux(h, 0), aux(h, 1)],
-                    [lvl_stub, rt_stub]
-                )
             }
             &QueryInstruction::PutPartialString(lvl, ref s, r, has_tail) => {
                 let lvl_stub = lvl.into_functor();
-                let rt_stub  = reg_type_into_functor(r);
+                let rt_stub = reg_type_into_functor(r);
 
                 functor!(
                     "put_partial_string",
@@ -772,29 +701,17 @@ impl QueryInstruction {
             &QueryInstruction::PutValue(r, arg) => {
                 let rt_stub = reg_type_into_functor(r);
 
-                functor!(
+                functor!("put_value", [aux(h, 0), integer(arg)], [rt_stub])
-                    "put_value",
-                    [aux(h, 0), integer(arg)],
-                    [rt_stub]
-                )
             }
             &QueryInstruction::GetVariable(r, arg) => {
                 let rt_stub = reg_type_into_functor(r);
 
-                functor!(
+                functor!("get_variable", [aux(h, 0), integer(arg)], [rt_stub])
-                    "get_variable",
-                    [aux(h, 0), integer(arg)],
-                    [rt_stub]
-                )
             }
             &QueryInstruction::PutVariable(r, arg) => {
                 let rt_stub = reg_type_into_functor(r);
 
-                functor!(
+                functor!("put_variable", [aux(h, 0), integer(arg)], [rt_stub])
-                    "put_variable",
-                    [aux(h, 0), integer(arg)],
-                    [rt_stub]
-                )
             }
             &QueryInstruction::SetConstant(ref c) => {
                 functor!("set_constant", [constant(h, c)], [])
@@ -802,29 +719,17 @@ impl QueryInstruction {
             &QueryInstruction::SetLocalValue(r) => {
                 let rt_stub = reg_type_into_functor(r);
 
-                functor!(
+                functor!("set_local_value", [aux(h, 0)], [rt_stub])
-                    "set_local_value",
-                    [aux(h, 0)],
-                    [rt_stub]
-                )
             }
             &QueryInstruction::SetVariable(r) => {
                 let rt_stub = reg_type_into_functor(r);
 
-                functor!(
+                functor!("set_variable", [aux(h, 0)], [rt_stub])
-                    "set_variable",
-                    [aux(h, 0)],
-                    [rt_stub]
-                )
             }
             &QueryInstruction::SetValue(r) => {
                 let rt_stub = reg_type_into_functor(r);
 
-                functor!(
+                functor!("set_value", [aux(h, 0)], [rt_stub])
-                    "set_value",
-                    [aux(h, 0)],
-                    [rt_stub]
-                )
             }
             &QueryInstruction::SetVoid(vars) => {
                 functor!("set_void", [integer(vars)])

src/iterators.rs

@@ -1,4 +1,5 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
+use prolog_parser::rc_atom;
 
 use crate::clause_types::*;
 use crate::forms::*;
@@ -25,11 +26,11 @@ impl<'a> TermRef<'a> {
     pub fn level(self) -> Level {
         match self {
             TermRef::AnonVar(lvl)
-          | TermRef::Cons(lvl, ..)
+            | TermRef::Cons(lvl, ..)
-          | TermRef::Constant(lvl, ..)
+            | TermRef::Constant(lvl, ..)
-          | TermRef::Var(lvl, ..)
+            | TermRef::Var(lvl, ..)
-          | TermRef::Clause(lvl, ..) => lvl,
+            | TermRef::Clause(lvl, ..) => lvl,
-          | TermRef::PartialString(lvl, ..) => lvl,
+            TermRef::PartialString(lvl, ..) => lvl,
         }
     }
 }
@@ -51,23 +52,16 @@ pub enum TermIterState<'a> {
     Var(Level, &'a Cell<VarReg>, Rc<Var>),
 }
 
-fn is_partial_string<'a>(
+fn is_partial_string<'a>(head: &'a Term, mut tail: &'a Term) -> Option<(String, Option<&'a Term>)> {
-    head: &'a Term,
+    let mut string = match head {
-    mut tail: &'a Term,
+        &Term::Constant(_, Constant::Atom(ref atom, _)) if atom.is_char() => {
-) -> Option<(String, Option<&'a Term>)>
+            atom.as_str().chars().next().unwrap().to_string()
-{
+        }
-    let mut string =
+        &Term::Constant(_, Constant::Char(c)) => c.to_string(),
-        match head {
+        _ => {
-            &Term::Constant(_, Constant::Atom(ref atom, _)) if atom.is_char() => {
+            return None;
-                atom.as_str().chars().next().unwrap().to_string()
+        }
-            }
+    };
-            &Term::Constant(_, Constant::Char(c)) => {
-                c.to_string()
-            }
-            _ => {
-                return None;
-            }
-        };
 
     while let Term::Cons(_, ref head, ref succ) = tail {
         match head.as_ref() {
@@ -105,9 +99,7 @@ fn is_partial_string<'a>(
 impl<'a> TermIterState<'a> {
     pub fn subterm_to_state(lvl: Level, term: &'a Term) -> TermIterState<'a> {
         match term {
-            &Term::AnonVar => {
+            &Term::AnonVar => TermIterState::AnonVar(lvl),
-                TermIterState::AnonVar(lvl)
-            }
             &Term::Clause(ref cell, ref name, ref subterms, ref spec) => {
                 let ct = if let Some(spec) = spec {
                     ClauseType::Op(name.clone(), spec.clone(), CodeIndex::default())
@@ -120,12 +112,8 @@ impl<'a> TermIterState<'a> {
             &Term::Cons(ref cell, ref head, ref tail) => {
                 TermIterState::InitialCons(lvl, cell, head.as_ref(), tail.as_ref())
             }
-            &Term::Constant(ref cell, ref constant) => {
+            &Term::Constant(ref cell, ref constant) => TermIterState::Constant(lvl, cell, constant),
-                TermIterState::Constant(lvl, cell, constant)
+            &Term::Var(ref cell, ref var) => TermIterState::Var(lvl, cell, var.clone()),
-            }
-            &Term::Var(ref cell, ref var) => {
-                TermIterState::Var(lvl, cell, var.clone())
-            }
         }
     }
 }
@@ -175,8 +163,7 @@ impl<'a> QueryIterator<'a> {
                     state_stack: vec![],
                 }
             }
-            &Term::Var(ref cell, ref var) =>
+            &Term::Var(ref cell, ref var) => TermIterState::Var(Level::Root, cell, (*var).clone()),
-                TermIterState::Var(Level::Root, cell, (*var).clone()),
         };
 
         QueryIterator {
@@ -265,18 +252,15 @@ impl<'a> Iterator for QueryIterator<'a> {
                 }
                 TermIterState::InitialCons(lvl, cell, head, tail) => {
                     if let Some((string, tail)) = is_partial_string(head, tail) {
-                        self.state_stack.push(TermIterState::PartialString(
+                        self.state_stack
-                            lvl,
+                            .push(TermIterState::PartialString(lvl, cell, string, tail));
-                            cell,
-                            string,
-                            tail,
-                        ));
 
                         if let Some(tail) = tail {
                             self.push_subterm(lvl.child_level(), tail);
                         }
                     } else {
-                        self.state_stack.push(TermIterState::FinalCons(lvl, cell, head, tail));
+                        self.state_stack
+                            .push(TermIterState::FinalCons(lvl, cell, head, tail));
 
                         self.push_subterm(lvl.child_level(), tail);
                         self.push_subterm(lvl.child_level(), head);
@@ -309,7 +293,8 @@ pub struct FactIterator<'a> {
 
 impl<'a> FactIterator<'a> {
     fn push_subterm(&mut self, lvl: Level, term: &'a Term) {
-        self.state_queue.push_back(TermIterState::subterm_to_state(lvl, term));
+        self.state_queue
+            .push_back(TermIterState::subterm_to_state(lvl, term));
     }
 
     pub fn from_rule_head_clause(terms: &'a Vec<Box<Term>>) -> Self {
@@ -393,8 +378,7 @@ impl<'a> Iterator for FactIterator<'a> {
                 TermIterState::Var(lvl, cell, var) => {
                     return Some(TermRef::Var(lvl, cell, var));
                 }
-                _ => {
+                _ => {}
-                }
             }
         }
 
@@ -481,16 +465,16 @@ impl<'a> ChunkedIterator<'a> {
             }
         }))
     }
-/*
+    /*
-    pub fn from_term_sequence(terms: &'a [QueryTerm]) -> Self {
+        pub fn from_term_sequence(terms: &'a [QueryTerm]) -> Self {
-        ChunkedIterator {
+            ChunkedIterator {
-            chunk_num: 0,
+                chunk_num: 0,
-            iter: Box::new(terms.iter().map(|t| ChunkedTerm::BodyTerm(t))),
+                iter: Box::new(terms.iter().map(|t| ChunkedTerm::BodyTerm(t))),
-            deep_cut_encountered: false,
+                deep_cut_encountered: false,
-            cut_var_in_head: false,
+                cut_var_in_head: false,
+            }
         }
-    }
+    */
-*/
     pub fn from_rule_body(p1: &'a QueryTerm, clauses: &'a Vec<QueryTerm>) -> Self {
         let inner_iter = Box::new(once(ChunkedTerm::BodyTerm(p1)));
         let iter = inner_iter.chain(clauses.iter().map(|t| ChunkedTerm::BodyTerm(t)));

src/lib/builtins.pl

@@ -4,9 +4,10 @@
                      abolish/1, asserta/1, assertz/1,
                      at_end_of_stream/0, at_end_of_stream/1,
                      atom_chars/2, atom_codes/2, atom_concat/3,
-                     atom_length/2, bagof/3, catch/3, char_code/2,
+                     atom_length/2, bagof/3, call/1, call/2, call/3,
-                     clause/2, close/1, close/2, current_input/1,
+                     call/4, call/5, call/6, call/7, call/8, call/9,
-                     current_output/1, current_op/3,
+                     catch/3, char_code/2, clause/2, close/1, close/2,
+                     current_input/1, current_output/1, current_op/3,
                      current_predicate/1, current_prolog_flag/2,
                      fail/0, false/0, findall/3, findall/4,
                      flush_output/0, flush_output/1, get_byte/1,
@@ -38,6 +39,30 @@ true.
 
 false :- '$fail'.
 
+
+% These are stub versions of call/{1-9} defined for bootstrapping.
+% Once Scryer is bootstrapped, each is replaced with a version that
+% uses expand_goal to pass the expanded goal along to '$call'.
+
+call(G) :- '$call'(G).
+
+call(G, A) :- '$call'(G, A).
+
+call(G, A, B) :- '$call'(G, A, B).
+
+call(G, A, B, C) :- '$call'(G, A, B, C).
+
+call(G, A, B, C, D) :- '$call'(G, A, B, C, D).
+
+call(G, A, B, C, D, E) :- '$call'(G, A, B, C, D, E).
+
+call(G, A, B, C, D, E, F) :- '$call'(G, A, B, C, D, E, F).
+
+call(G, A, B, C, D, E, F, G) :- '$call'(G, A, B, C, D, E, F, G).
+
+call(G, A, B, C, D, E, F, G, H) :- '$call'(G, A, B, C, D, E, F, G, H).
+
+
 Module : Predicate :-
     ( atom(Module) ->
       '$module_call'(Module, Predicate)
@@ -209,6 +234,8 @@ G1 -> G2 :-
     ).
 
 
+:-non_counted_backtracking call_or_cut/3.
+
 call_or_cut(G, B, ErrorPI) :-
     (  '$call_with_default_policy'(var(G)) ->
        throw(error(instantiation_error, ErrorPI))
@@ -216,55 +243,71 @@ call_or_cut(G, B, ErrorPI) :-
     ).
 
 
-call_or_cut(!, B) :-
+:- non_counted_backtracking call_or_cut/2.
+
+call_or_cut(M:G, B) :-
+    !,
+    (  nonvar(G),
+       '$call_with_default_policy'(call_or_cut_interp(G, B)) ->
+       true
+    ;  call(M:G)
+    ).
+call_or_cut(G, B) :-
+    (  '$call_with_default_policy'(call_or_cut_interp(G, B)) ->
+       true
+    ;  call(G)
+    ).
+
+
+:- non_counted_backtracking call_or_cut_interp/2.
+
+call_or_cut_interp(!, B) :-
     '$set_cp_by_default'(B).
-call_or_cut((G1, G2), B) :-
+call_or_cut_interp((G1, G2), B) :-
-    !,
     '$call_with_default_policy'(','(G1, G2, B)).
-call_or_cut((G1 ; G2), B) :-
+call_or_cut_interp((G1 ; G2), B) :-
-    !,
     '$call_with_default_policy'(';'(G1, G2, B)).
-call_or_cut((G1 -> G2), B) :-
+call_or_cut_interp((G1 -> G2), B) :-
-    !,
     '$call_with_default_policy'(->(G1, G2, B)).
-call_or_cut(G, _) :-
-    '$call_with_default_policy'(G).
 
 
 :- non_counted_backtracking (',')/3.
-','((G1, G2), G3, B) :-
+
+','(M:G1, G2, B) :-
     !,
-    '$call_with_default_policy'(','(G1, G2, B)),
+    (  nonvar(G1),
-    '$call_with_default_policy'(call_or_cut(G3, B, (',')/2)).
+       '$call_with_default_policy'(',-interp'(G1, G2, B)) ->
-','((G1; G2), G3, B) :-
+       true
-    !,
+    ;  call(M:G1),
-    '$call_with_default_policy'(';'(G1, G2, B)),
+       '$call_with_default_policy'(call_or_cut(G2, B, (',')/2))
-    '$call_with_default_policy'(call_or_cut(G3, B, (',')/2)).
+    ).
-','((G1 -> G2), G3, B) :-
-    !,
-    '$call_with_default_policy'(->(G1, G2, B)),
-    '$call_with_default_policy'(call_or_cut(G3, B, (',')/2)).
 ','(G1, G2, B) :-
     '$call_with_default_policy'(call_or_cut(G1, B, (',')/2)),
     '$call_with_default_policy'(call_or_cut(G2, B, (',')/2)).
 
 
+:- non_counted_backtracking (',-interp')/3.
+
+',-interp'((G1, G2), G3, B) :-
+    '$call_with_default_policy'(','(G1, G2, B)),
+    '$call_with_default_policy'(call_or_cut(G3, B, (',')/2)).
+',-interp'((G1; G2), G3, B) :-
+    '$call_with_default_policy'(';'(G1, G2, B)),
+    '$call_with_default_policy'(call_or_cut(G3, B, (',')/2)).
+',-interp'((G1 -> G2), G3, B) :-
+    '$call_with_default_policy'(->(G1, G2, B)),
+    '$call_with_default_policy'(call_or_cut(G3, B, (',')/2)).
+
+
 :- non_counted_backtracking (;)/3.
-';'((G1, G2), G3, B) :-
+
+';'(M:G1, G2, B) :-
     !,
-    (  '$call_with_default_policy'(','(G1, G2, B))
+    (  nonvar(G1),
-    ;  '$call_with_default_policy'(call_or_cut(G3, B, (;)/2))
+       '$call_with_default_policy'(';-interp'(G1, G2, B)) ->
-    ).
+       true
-';'((G1; G2), G3, B) :-
+    ;  call(M:G1)
-    !,
+    ;  '$call_with_default_policy'(call_or_cut(G2, B, (;)/2))
-    (  '$call_with_default_policy'(';'(G1, G2, B))
-    ;  '$call_with_default_policy'(call_or_cut(G3, B, (;)/2))
-    ).
-';'((G1 -> G2), G3, B) :-
-    !,
-    (  '$call_with_default_policy'(call_or_cut(G1, B, (->)/2)) ->
-       '$call_with_default_policy'(call_or_cut(G2, B, (->)/2))
-    ;  '$call_with_default_policy'(call_or_cut(G3, B, (;)/2))
     ).
 ';'(G1, G2, B) :-
     (  '$call_with_default_policy'(call_or_cut(G1, B, (;)/2))
@@ -272,26 +315,54 @@ call_or_cut(G, _) :-
     ).
 
 
+:- non_counted_backtracking ';-interp'/3.
+
+';-interp'((G1, G2), G3, B) :-
+    (  '$call_with_default_policy'(','(G1, G2, B))
+    ;  '$call_with_default_policy'(call_or_cut(G3, B, (;)/2))
+    ).
+';-interp'((G1; G2), G3, B) :-
+    (  '$call_with_default_policy'(';'(G1, G2, B))
+    ;  '$call_with_default_policy'(call_or_cut(G3, B, (;)/2))
+    ).
+';-interp'((G1 -> G2), G3, B) :-
+    (  '$call_with_default_policy'(call_or_cut(G1, B, (->)/2)) ->
+       '$call_with_default_policy'(call_or_cut(G2, B, (->)/2))
+    ;  '$call_with_default_policy'(call_or_cut(G3, B, (;)/2))
+    ).
+
+
 :- non_counted_backtracking (->)/3.
-->((G1, G2), G3, B) :-
+
+->(M:G1, G2, B) :-
     !,
+    (  nonvar(G1),
+       '$call_with_default_policy'('->-interp'(G1, G2, B)) ->
+       true
+    ;  call(M:G1) ->
+       '$call_with_default_policy'(call_or_cut(G2, B, (->)/2))
+    ).
+->(G1, G2, B) :-
+    (  '$call_with_default_policy'(call_or_cut(G1, B, (->)/2)) ->
+       '$call_with_default_policy'(call_or_cut(G2, B, (->)/2))
+    ).
+
+
+:- non_counted_backtracking '->-interp'/3.
+
+'->-interp'((G1, G2), G3, B) :-
     (  '$call_with_default_policy'(','(G1, G2, B)) ->
        '$call_with_default_policy'(call_or_cut(G3, B, (->)/2))
     ).
-->((G1 ; G2), G3, B) :-
+'->-interp'((G1 ; G2), G3, B) :-
-    !,
     (  '$call_with_default_policy'(';'(G1, G2, B)) ->
        '$call_with_default_policy'(call_or_cut(G3, B, (->)/2))
     ).
-->((G1 -> G2), G3, B) :-
+'->-interp'((G1 -> G2), G3, B) :-
-    !,
     (  '$call_with_default_policy'(->(G1, G2, B)) ->
        '$call_with_default_policy'(call_or_cut(G3, B, (->)/2))
     ).
-->(G1, G2, B) :-
+
-    (   '$call_with_default_policy'(call_or_cut(G1, B, (->)/2))
-    ->  '$call_with_default_policy'(call_or_cut(G2, B, (->)/2))
-    ).
 
 % univ.
 
@@ -640,8 +711,11 @@ iterate_variants([V-Solution|GroupSolutions], V, Solution) :-
 iterate_variants([_|GroupSolutions], Ws, Solution) :-
     iterate_variants(GroupSolutions, Ws, Solution).
 
+
 rightmost_power(Term, FinalTerm, Xs) :-
-    (  Term = X ^ Y
+    (  (  Term = X ^ Y
+       ;  Term = _ : X ^ Y
+       )
     -> (  var(Y) -> FinalTerm = Y, Xs = [X]
        ;  Xs = [X | Xss], rightmost_power(Y, FinalTerm, Xss)
        )
@@ -649,11 +723,11 @@ rightmost_power(Term, FinalTerm, Xs) :-
     ).
 
 
-% :- meta_predicate findall_with_existential(?, 0, ?, ?, ?).
-
 findall_with_existential(Template, Goal, PairedSolutions, Witnesses0, Witnesses) :-
     (  nonvar(Goal),
-       Goal = _ ^ _ ->
+       (  Goal = _ ^ _
+       ;  Goal = _ : (_ ^ _)
+       )  ->
        rightmost_power(Goal, Goal1, ExistentialVars0),
        term_variables(ExistentialVars0, ExistentialVars),
        sort(Witnesses0, Witnesses1),
@@ -714,13 +788,16 @@ setof(Template, Goal, Solution) :-
     ).
 
 '$module_clause'(H, B, Module) :-
-    (  var(H) -> throw(error(instantiation_error, clause/2))
+    (  var(H) ->
+       throw(error(instantiation_error, clause/2))
     ;  functor(H, Name, Arity) ->
        (  Name == '.' ->
           throw(error(type_error(callable, H), clause/2))
+       ;  '$no_such_predicate'(Module, H) ->
+          '$fail'
 	   ;  '$head_is_dynamic'(Module, H) ->
 		  '$clause_body_is_valid'(B),
-		  Module:'$clause'(H, B) %%TODO: how do we show this exists?
+		  Module:'$clause'(H, B)
 	   ;  throw(error(permission_error(access, private_procedure, Name/Arity),
 					  clause/2))
 	   )
@@ -728,8 +805,6 @@ setof(Template, Goal, Solution) :-
     ).
 
 
-:- dynamic('$clause'/2).
-
 clause(H, B) :-
     (  var(H) ->
        throw(error(instantiation_error, clause/2))
@@ -753,24 +828,19 @@ clause(H, B) :-
     ;  throw(error(type_error(callable, H), clause/2))
     ).
 
-call_module_asserta(Head, Body, Name, Arity, Module) :-
+call_asserta(Head, Body, Name, Arity, Module) :-
     '$clause_body_is_valid'(Body),
-    functor(VarHead, Name, Arity),
+    functor(_, Name, Arity),
-    findall((VarHead :- VarBody), builtins:clause(Module:VarHead, VarBody), Clauses),
+    '$asserta'(Head, Body, Name, Arity, Module).
-    '$module_asserta'((Head :- Body), Clauses, Name, Arity, Module).
-
-call_asserta(Head, Body, Name, Arity) :-
-    '$clause_body_is_valid'(Body),
-    functor(VarHead, Name, Arity),
-    '$asserta'(Head, Body, Name, Arity).
 
 module_asserta_clause(Head, Body, Module) :-
-    (  var(Head) -> throw(error(instantiation_error, asserta/1))
+    (  var(Head) ->
+       throw(error(instantiation_error, asserta/1))
     ;  functor(Head, Name, Arity),
        atom(Name),
        Name \== '.' ->
-       (  '$module_head_is_dynamic'(Head, Module) ->
+       (  '$head_is_dynamic'(Module, Head) ->
-          call_module_asserta(Head, Body, Name, Arity, Module)
+          call_asserta(Head, Body, Name, Arity, Module)
        ;  throw(error(permission_error(modify, static_procedure, Name/Arity), asserta/1))
        )
     ;  throw(error(type_error(callable, Head), asserta/1))
@@ -787,9 +857,9 @@ asserta_clause(Head, Body) :-
 	     arg(2, Head, F),
 	     module_asserta_clause(F, Body, Module)
        ; '$no_such_predicate'(user, Head) ->
-         call_asserta(Head, Body, Name, Arity)
+         call_asserta(Head, Body, Name, Arity, user)
        ; '$head_is_dynamic'(user, Head) ->
-         call_asserta(Head, Body, Name, Arity)
+         call_asserta(Head, Body, Name, Arity, user)
        ;  throw(error(permission_error(modify, static_procedure, Name/Arity), asserta/1))
        )
     ;  throw(error(type_error(callable, Head), asserta/1))
@@ -798,36 +868,33 @@ asserta_clause(Head, Body) :-
 asserta(Clause) :-
     (  Clause \= (_ :- _) ->
        Head = Clause,
-       Body = true, asserta_clause(Head, Body)
+       Body = true,
+       asserta_clause(Head, Body)
     ;  Clause = (Head :- Body) ->
        asserta_clause(Head, Body)
     ).
 
-% NOT MODIFIED.
-call_module_assertz(Head, Body, Name, Arity, Module) :-
-    '$clause_body_is_valid'(Body),
-    functor(VarHead, Name, Arity),
-    findall((VarHead :- VarBody), builtins:clause(Module:VarHead, VarBody), Clauses),
-    '$module_assertz'((Head :- Body), Clauses, Name, Arity, Module).
-
 module_assertz_clause(Head, Body, Module) :-
     (  var(Head) ->
        throw(error(instantiation_error, assertz/1))
     ;  functor(Head, Name, Arity),
        atom(Name),
        Name \== '.' ->
-       (  '$head_is_dynamic'(Module, Head) ->
+       (  '$no_such_predicate'(Module, Head) ->
-          call_module_assertz(Head, Body, Name, Arity, Module)
+	      call_assertz(Head, Body, Name, Arity, Module)
-       ;  throw(error(permission_error(modify, static_procedure, Name/Arity), assertz/1))
+       ;  '$head_is_dynamic'(Module, Head) ->
+          call_assertz(Head, Body, Name, Arity, Module)
+       ;  throw(error(permission_error(modify, static_procedure, Name/Arity),
+                      assertz/1))
        )
     ;  throw(error(type_error(callable, Head), assertz/1))
     ).
 
-% MODIFIED.
+
-call_assertz(Head, Body, Name, Arity) :-
+call_assertz(Head, Body, Name, Arity, Module) :-
     '$clause_body_is_valid'(Body),
-    functor(VarHead, Name, Arity),
+    functor(_, Name, Arity),
-    '$assertz'(Head, Body, Name, Arity).
+    '$assertz'(Head, Body, Name, Arity, Module).
 
 assertz_clause(Head, Body) :-
     (  var(Head) ->
@@ -835,16 +902,17 @@ assertz_clause(Head, Body) :-
     ;  functor(Head, Name, Arity),
        atom(Name),
        Name \== '.' ->
-       ( Name == (:),
+       (  Name == (:),
-         Arity =:= 2 ->
+          Arity =:= 2 ->
-	     arg(1, Head, Module),
+	      arg(1, Head, Module),
-	     arg(2, Head, F),
+	      arg(2, Head, F),
-	     module_assertz_clause(F, Body, Module)
+	      module_assertz_clause(F, Body, Module)
-       ; '$no_such_predicate'(user, Head) ->
+       ;  '$no_such_predicate'(user, Head) ->
-	     call_assertz(Head, Body, Name, Arity)
+	      call_assertz(Head, Body, Name, Arity, user)
-       ; '$head_is_dynamic'(user, Head) ->
+       ;  '$head_is_dynamic'(user, Head) ->
-	     call_assertz(Head, Body, Name, Arity)
+	      call_assertz(Head, Body, Name, Arity, user)
-       ; throw(error(permission_error(modify, static_procedure, Name/Arity), assertz/1))
+       ;  throw(error(permission_error(modify, static_procedure, Name/Arity),
+                      assertz/1))
        )
     ;  throw(error(type_error(callable, Head), assertz/1))
     ).
@@ -861,18 +929,18 @@ assertz(Clause) :-
 
 module_retract_clauses([Clause|Clauses0], Head, Body, Name, Arity, Module) :-
     functor(VarHead, Name, Arity),
-    findall((VarHead :- VarBody), builtins:clause(Module:VarHead, VarBody), Clauses1),
+    findall((VarHead :- VarBody), Module:'$clause'(VarHead, VarBody), Clauses1),
     first_match_index(Clauses1, (Head :- Body), 0, N),
     (  Clauses0 == [] -> !
     ;  true
     ),
-    '$module_retract_clause'(Name, Arity, N, Clauses1, Module).
+    '$retract_clause'(Name, Arity, N, Module).
 
 module_retract_clauses([_|Clauses0], Head, Body, Name, Arity, Module) :-
     module_retract_clauses(Clauses0, Head, Body, Name, Arity, Module).
 
 call_module_retract(Head, Body, Name, Arity, Module) :-
-    findall((Head :- Body), builtins:clause(Module:Head, Body), Clauses),
+    findall((Head :- Body), Module:'$clause'(Head, Body), Clauses),
     module_retract_clauses(Clauses, Head, Body, Name, Arity, Module).
 
 retract_module_clause(Head, Body, Module) :-
@@ -881,9 +949,12 @@ retract_module_clause(Head, Body, Module) :-
     ;  functor(Head, Name, Arity),
        atom(Name),
        Name \== '.' ->
-       ( '$module_head_is_dynamic'(Head, Module) ->
+       (  '$head_is_dynamic'(Module, Head) ->
-	     call_module_retract(Head, Body, Name, Arity, Module)
+          (  Module == user ->
-       ; throw(error(permission_error(modify, static_procedure, Name/Arity), retract/1))
+             call_retract(Head, Body, Name, Arity)
+          ;  call_module_retract(Head, Body, Name, Arity, Module)
+          )
+       ;  throw(error(permission_error(modify, static_procedure, Name/Arity), retract/1))
        )
     ;  throw(error(type_error(callable, Head), retract/1))
     ).
@@ -904,7 +975,7 @@ retract_clauses([Clause | Clauses0], Head, Body, Name, Arity) :-
     (  Clauses0 == [] -> !
     ;  true
     ),
-    '$retract_clause'(Name, Arity, N).
+    '$retract_clause'(Name, Arity, N, user).
 
 retract_clauses([_ | Clauses0], Head, Body, Name, Arity) :-
     retract_clauses(Clauses0, Head, Body, Name, Arity).
@@ -919,16 +990,16 @@ retract_clause(Head, Body) :-
     ;  functor(Head, Name, Arity),
        atom(Name),
        Name \== '.' ->
-       ( Name == (:),
+       (  Name == (:),
-         Arity =:= 2 ->
+          Arity =:= 2 ->
-	     arg(1, Head, Module),
+	      arg(1, Head, Module),
-	     arg(2, Head, F),
+	      arg(2, Head, F),
-	     retract_module_clause(F, Body, Module)
+	      retract_module_clause(F, Body, Module)
-       ; '$head_is_dynamic'(user, Head) ->
+       ;  '$head_is_dynamic'(user, Head) ->
-         call_retract(Head, Body, Name, Arity)
+          call_retract(Head, Body, Name, Arity)
-       ; '$no_such_predicate'(user, Head) ->
+       ;  '$no_such_predicate'(user, Head) ->
-         '$fail'
+          '$fail'
-       ; throw(error(permission_error(modify, static_procedure, Name/Arity), retract/1))
+       ;  throw(error(permission_error(modify, static_procedure, Name/Arity), retract/1))
        )
     ;  throw(error(type_error(callable, Head), retract/1))
     ).
@@ -950,21 +1021,21 @@ module_abolish(Pred, Module) :-
        (  var(Name)  ->
           throw(error(instantiation_error, abolish/1))
        ;  integer(Arity) ->
-	      ( \+ atom(Name) ->
+	      (  \+ atom(Name) ->
-            throw(error(type_error(atom, Name), abolish/1))
+             throw(error(type_error(atom, Name), abolish/1))
-	      ; Arity < 0 ->
+	      ;  Arity < 0 ->
-            throw(error(domain_error(not_less_than_zero, Arity), abolish/1))
+             throw(error(domain_error(not_less_than_zero, Arity), abolish/1))
-	      ; max_arity(N), Arity > N ->
+	      ;  max_arity(N), Arity > N ->
-            throw(error(representation_error(max_arity), abolish/1))
+             throw(error(representation_error(max_arity), abolish/1))
-	      ; functor(Head, Name, Arity) ->
+	      ;  functor(Head, Name, Arity) ->
-	        (  '$module_head_is_dynamic'(Head, Module) ->
+	         (  '$head_is_dynamic'(Module, Head) ->
-	           '$abolish_module_clause'(Name, Arity, Module)
+	            '$abolish_clause'(Module, Name, Arity)
-	        ;  throw(error(permission_error(modify, static_procedure, Pred), abolish/1))
+	         ;  throw(error(permission_error(modify, static_procedure, Pred), abolish/1))
-	        )
+	         )
 	      )
        ;  throw(error(type_error(integer, Arity), abolish/1))
        )
-    ; throw(error(type_error(predicate_indicator, Module:Pred), abolish/1))
+    ;  throw(error(type_error(predicate_indicator, Module:Pred), abolish/1))
     ).
 
 abolish(Pred) :-
@@ -978,17 +1049,19 @@ abolish(Pred) :-
        ;  var(Arity) ->
           throw(error(instantiation_error, abolish/1))
        ;  integer(Arity) ->
-	      ( \+ atom(Name) ->
+	      (  \+ atom(Name) ->
-            throw(error(type_error(atom, Name), abolish/1))
+             throw(error(type_error(atom, Name), abolish/1))
-	      ; Arity < 0 ->
+	      ;  Arity < 0 ->
-            throw(error(domain_error(not_less_than_zero, Arity), abolish/1))
+             throw(error(domain_error(not_less_than_zero, Arity), abolish/1))
-	      ; max_arity(N), Arity > N ->
+	      ;  max_arity(N), Arity > N ->
-            throw(error(representation_error(max_arity), abolish/1))
+             throw(error(representation_error(max_arity), abolish/1))
-	      ; functor(Head, Name, Arity) ->
+	      ;  functor(Head, Name, Arity) ->
-	        (  '$no_such_predicate'(Head) -> true
+	         (  '$no_such_predicate'(user, Head) ->
-	        ;  '$head_is_dynamic'(Head) -> '$abolish_clause'(Name, Arity)
+                true
-	        ;  throw(error(permission_error(modify, static_procedure, Pred), abolish/1))
+	         ;  '$head_is_dynamic'(user, Head) ->
-	        )
+                '$abolish_clause'(user, Name, Arity)
+	         ;  throw(error(permission_error(modify, static_procedure, Pred), abolish/1))
+	         )
 	      )
        ;  throw(error(type_error(integer, Arity), abolish/1))
        )

src/lib/clpz.pl

@@ -3068,12 +3068,10 @@ is_false(var(X)) :- nonvar(X).
 
 :- dynamic(goal_expansion/1).
 
-% goal expansion is disabled for now, until #445 is resolved
+user:goal_expansion(Goal0, Goal) :-
-%
+        \+ goal_expansion(false),
-% user:goal_expansion(Goal0, Goal) :-
+        clpz_expandable(Goal0),
-%         \+ goal_expansion(false),
+        clpz_expansion(Goal0, Goal).
-%         clpz_expandable(Goal0),
-%         clpz_expansion(Goal0, Goal).
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 

src/lib/ops_and_meta_predicates.pl

@@ -125,3 +125,5 @@
 :- meta_predicate call(61, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?).
 :- meta_predicate call(62, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?).
 :- meta_predicate call(63, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?).
+:- meta_predicate call(64, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?).
+:- meta_predicate call(65, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?).

src/lib/sockets.pl

@@ -15,7 +15,7 @@ parse_socket_options_(Option, OptionPair) :-
 
 parse_socket_options(Options, OptionValues, Stub) :-
     DefaultOptions = [alias-[], eof_action-eof_code, reposition-false, tls-false, type-text],
-    builtins:parse_options_list(Options, parse_socket_options_, DefaultOptions, OptionValues, Stub).
+    builtins:parse_options_list(Options, sockets:parse_socket_options_, DefaultOptions, OptionValues, Stub).
 
 socket_client_open(Addr, Stream, Options) :-
     (  var(Addr) ->

src/loader.pl

@@ -18,14 +18,14 @@
 
 
 '$print_message_and_fail'(Error, Culprit) :-
-%    writeq(error(Error, Culprit)),
+    %    writeq(error(Error, Culprit)),
-%    nl,
+    %    nl,
     '$fail'.
 
 expand_term(Term, ExpandedTerm) :-
-    (  catch(user:term_expansion(Term, ExpandedTerm0),
+    (  catch('$call'(user:term_expansion(Term, ExpandedTerm0)),
              E,
-             loader:'$print_message_and_fail'(E, user:term_expansion)) ->
+             '$call'(loader:'$print_message_and_fail'(E, user:term_expansion))) ->
        (  var(ExpandedTerm0) ->
           error:instantiation_error(term_expansion/2)
        ;  ExpandedTerm0 = [_|_] ->
@@ -35,7 +35,6 @@ expand_term(Term, ExpandedTerm) :-
     ;  Term = ExpandedTerm
     ).
 
-
 term_expansion_list([], ExpandedTerms, ExpandedTerms).
 term_expansion_list([Term|Terms], ExpandedTermsHead, ExpandedTermsTail) :-
     expand_term(Term, ExpandedTerm0),
@@ -50,9 +49,9 @@ term_expansion_list([Term|Terms], ExpandedTermsHead, ExpandedTermsTail) :-
 
 
 goal_expansion(Goal, Module, ExpandedGoal) :-
-    (  catch(Module:goal_expansion(Goal, ExpandedGoal0),
+    (  catch('$call'(Module:goal_expansion(Goal, ExpandedGoal0)),
              E,
-             loader:'$print_message_and_fail'(E, Module:goal_expansion)) ->
+             '$call'(loader:'$print_message_and_fail'(E, Module:goal_expansion))) ->
        (  var(ExpandedGoal0) ->
           error:instantiation_error(goal_expansion/2)
        ;  goal_expansion(ExpandedGoal0, Module, ExpandedGoal)
@@ -74,6 +73,16 @@ unload_evacuable(Evacuable) :-
     '$pop_load_state_payload'(Evacuable),
     '$pop_load_context'.
 
+run_initialization_goals :-
+    prolog_load_context(module, Module),
+    (  predicate_property(Module:'$initialization_goals'(_), dynamic) ->
+       findall(Goal, '$call'(builtins:retract(Module:'$initialization_goals'(Goal))), Goals),
+       (  maplist(Module:call, Goals) ->
+          true
+       ;  true %% initialization goals can fail without thwarting the load.
+       )
+    ;  true
+    ).
 
 file_load(Stream, Path) :-
     file_load(Stream, Path, _).
@@ -83,6 +92,7 @@ file_load(Stream, Path, Evacuable) :-
     catch(loader:load_loop(Stream, Evacuable),
           E,
           (loader:unload_evacuable(Evacuable), throw(E))),
+    run_initialization_goals,
     '$pop_load_context'.
 
 
@@ -91,6 +101,7 @@ load(Stream) :-
     catch(loader:load_loop(Stream, Evacuable),
           E,
           (loader:unload_evacuable(Evacuable), throw(E))),
+    run_initialization_goals,
     '$pop_load_context'.
 
 load_loop(Stream, Evacuable) :-
@@ -195,8 +206,7 @@ compile_dispatch_or_clause(Term, Evacuable, VNs) :-
 compile_dispatch((:- Declaration), Evacuable, _VNs) :-
     (  var(Declaration) ->
        instantiation_error(load/1)
-    ;
+    ;  compile_declaration(Declaration, Evacuable)
-       compile_declaration(Declaration, Evacuable)
     ).
 compile_dispatch(term_expansion(Term, Terms), Evacuable, VNs) :-
     '$add_term_expansion_clause'(term_expansion(Term, Terms), Evacuable, VNs).
@@ -224,13 +234,13 @@ compile_declaration(use_module(Module, Exports), Evacuable) :-
     (  Exports == [] ->
        '$remove_module_exports'(Module, Evacuable) % TODO: implement this.
     ;
-       use_module(Module, Exports, Evacuable)
+    use_module(Module, Exports, Evacuable)
     ).
 compile_declaration(module(Module, Exports), Evacuable) :-
     ( atom(Module) ->
       '$declare_module'(Module, Exports, Evacuable)
     ;
-      type_error(atom, Module, load/1)
+    type_error(atom, Module, load/1)
     ).
 compile_declaration(dynamic(Name/Arity), Evacuable) :-
     must_be(atom, Name),
@@ -238,9 +248,8 @@ compile_declaration(dynamic(Name/Arity), Evacuable) :-
     '$add_dynamic_predicate'(Name, Arity, Evacuable).
 compile_declaration(initialization(Goal), Evacuable) :-
     prolog_load_context(module, Module),
-    '$compile_pending_predicates'(Evacuable),
+    assertz(Module:'$initialization_goals'(Goal)).
-    expand_goal(call(Goal), Module, call(ExpandedGoal)),
+
-    call(ExpandedGoal).
 
 
 compile_clause(Clause, Evacuable, VNs) :-
@@ -290,45 +299,64 @@ use_module(Module, Exports) :-
     '$push_load_state_payload'(Evacuable),
     (  Exports == [] ->
        '$remove_module_exports'(Module, Evacuable)
-    ;
+    ;  use_module(Module, Exports, Evacuable)
-       use_module(Module, Exports, Evacuable)
     ).
 
 
 %% If use_module is invoked in an existing load context, use its
 %% directory. Otherwise, use the relative path of Path.
+
 load_context_path(Module, Path) :-
     (  prolog_load_context(directory, CurrentDir) ->
-       atom_concat(CurrentDir, Path, Module)
+       % Rust's Path module never ends a directory path with '/', so
-    ;
+       % add one here.
-       Module = Path
+       atom_concat(CurrentDir, '/', CurrentDirSlashed),
+       atom_concat(CurrentDirSlashed, Module, Path)
+    ;  Module = Path
     ).
 
+path_atom(Dir/File, Path) :-
+    must_be(atom, File),
+    !,
+    path_atom(Dir, DirPath),
+    foldl(builtins:atom_concat, ['/', DirPath], File, Path).
+path_atom(Path, Path) :-
+    must_be(atom, Path).
+
+% Try to open the file with the Path name as given; if that fails,
+% append '.pl' and try again.
+open_file(Path, Stream) :-
+    (  atom_concat(_, '.pl', Path) ->
+       open(Path, read, Stream)
+    ;  catch(open(Path, read, Stream),
+             error(existence_error(source_sink, Path), _),
+             ( atom_concat(Path, '.pl', ExtendedPath),
+               open(ExtendedPath, read, Stream) )
+            )
+    ).
 
 use_module(Module, Exports, Evacuable) :-
     (  var(Module) ->
        instantiation_error(load/1)
     ;  Module = library(Library) ->
-       (  atom(Library) ->
+       (  path_atom(Library, LibraryPath) ->
-          (  '$load_compiled_library'(Library, Evacuable) -> %% TODO: What about Exports?
+          (  '$load_compiled_library'(LibraryPath, Evacuable) -> %% TODO: What about Exports?
              true
-          ;
+          ;  '$load_library_as_stream'(LibraryPath, Stream, Path),
-             '$load_library_as_stream'(Library, Stream, Path),
              file_load(Stream, Path, Subevacuable),
              '$use_module'(Evacuable, Subevacuable, Exports)
           )
        ;  var(Library) ->
           instantiation_error(load/1)
-       ;
+       ;  type_error(atom, Library, load/1)
-          type_error(atom, Library, load/1)
+       )
+    ;  (  path_atom(Module, ModulePath) ->
+          load_context_path(ModulePath, Path),
+          open_file(Path, Stream),
+          file_load(Stream, Path, Subevacuable),
+          '$use_module'(Evacuable, Subevacuable, Exports)
+       ;  type_error(atom, Library, load/1)
        )
-    ;  atom(Module) ->
-       load_context_path(Module, Path),
-       open(Path, read, Stream),
-       file_load(Stream, Path, Subevacuable),
-       '$use_module'(Evacuable, Subevacuable, Exports)
-    ;
-       type_error(atom, Library, load/1)
     ).
 
 
@@ -337,6 +365,13 @@ check_predicate_property(meta_predicate, Module, Name, Arity, MetaPredicateTerm)
     '$cpp_meta_predicate_property'(Module, Name, Arity, MetaPredicateTerm).
 check_predicate_property(built_in, _, Name, Arity, built_in) :-
     '$cpp_built_in_property'(Name, Arity).
+check_predicate_property(dynamic, Module, Name, Arity, dynamic) :-
+    '$cpp_dynamic_property'(Module, Name, Arity).
+check_predicate_property(multifile, Module, Name, Arity, multifile) :-
+    '$cpp_multifile_property'(Module, Name, Arity).
+check_predicate_property(discontiguous, Module, Name, Arity, multifile) :-
+    '$cpp_discontiguous_property'(Module, Name, Arity).
+
 
 
 extract_predicate_property(Property, PropertyType) :-
@@ -345,35 +380,47 @@ extract_predicate_property(Property, PropertyType) :-
     ;  functor(Property, PropertyType, _)
     ).
 
+load_context(Module) :-
+    (  prolog_load_context(module, Module) ->
+       true
+    ;  Module = user
+    ).
+
 predicate_property(Callable, Property) :-
     (  var(Callable) ->
        instantiation_error(load/1)
-    ;  Callable =.. [(:), Module, Callable0],
+    ;  functor(Callable, (:), 2),  % Callable =.. [(:), Module, Callable0],
+       arg(1, Callable, Module),
+       arg(2, Callable, Callable0),
        atom(Module) ->
        functor(Callable0, Name, Arity),
-       extract_predicate_property(Property, PropertyType),
+       (  atom(Name),
-       check_predicate_property(PropertyType, Module, Name, Arity, Property)
+          Name \== [] ->
+          extract_predicate_property(Property, PropertyType),
+          check_predicate_property(PropertyType, Module, Name, Arity, Property)
+       ;  type_error(callable, Callable0, predicate_property/2)
+       )
     ;  functor(Callable, Name, Arity),
-       extract_predicate_property(Property, PropertyType),
+       (  atom(Name),
-       (  prolog_load_context(module, Module) ->
+          Name \== [] ->
-          true
+          extract_predicate_property(Property, PropertyType),
-       ;  Module = user
+          load_context(Module),
-       ),
+          check_predicate_property(PropertyType, Module, Name, Arity, Property)
-       check_predicate_property(PropertyType, Module, Name, Arity, Property)
+       ;  type_error(callable, Callable, predicate_property/2)
+       )
     ).
 
 
-strip_module_(M0, G0, M1, G1) :-
+strip_module(M0, G0, M1, G1) :-
     (  nonvar(G0),
        G0 = (MG1:G2) ->
-       strip_module_(MG1, G2, M1, G1)
+       strip_module(MG1, G2, M1, G1)
     ;  M0 = M1,
        G0 = G1
     ).
 
 strip_module(Goal, M, G) :-
-    strip_module_(_, Goal, M, G).
+    strip_module(_, Goal, M, G).
-
 
 
 expand_subgoal(UnexpandedGoals, MS, Module, ExpandedGoals, HeadVars) :-
@@ -498,3 +545,710 @@ thread_goals(Goals0, Goals1, Hole, Functor) :-
        ;  Goals1 =.. [Functor, Goals0, Hole]
        )
     ).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% call/{1-64} with dynamic goal expansion.
+%
+% The program used to generate the call/N predicates:
+%
+%
+% :- use_module(library(between)).
+% :- use_module(library(error)).
+% :- use_module(library(lists)).
+% :- use_module(library(format)).
+%
+% call_form_generator(N) :-
+%     length(Args, N),
+%     CallHead =.. [call, G | Args],
+%     N1 is N + 1,
+%     Form = (CallHead :- (  var(G) ->
+%                            instantiation_error(call/N1)
+%                         ;  call_clause(G, Args, N1, G0) ->
+%                            '$call'(G0)
+%                         ;  type_error(callable, G, call/N1)
+%                         )),
+%     portray_clause(Form).
+%
+% generate_call_forms :-
+%     between(1, 64, N),
+%     call_form_generator(N),
+%     nl,
+%     false.
+%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+
+call_clause(M:G1, G0) :-
+    functor(G1, F, _),
+    atom(F),
+    atom(M),
+    F \== [],
+    !,
+    expand_goal(M:G1, M, G0).
+
+% The '$call' functor is an escape hatch from goal expansion. So far,
+% it is used only to avoid infinite recursion into expand_goal/3.
+
+call_clause('$call'(G), G0) :-
+    (  var(G),
+       instantiation_error(call/1)
+    ;  G = M:G1,
+       !,
+       functor(G1, F, _),
+       atom(F),
+       atom(M),
+       F \== [],
+       G0 = M:G1
+    ;  !,
+       functor(G, F, _),
+       atom(F),
+       F \== [],
+       load_context(M),
+       G0 = M:G
+    ).
+
+call_clause(G, G0) :-
+    functor(G, F, _),
+    atom(F),
+    F \== [],
+    load_context(M),
+    expand_goal(M:G, M, G0).
+
+
+call(G) :-
+    (  var(G) ->
+       instantiation_error(call/1)
+    ;  call_clause(G, G0) ->
+       '$call'(G0)
+    ;  type_error(callable, G, call/1)
+    ).
+
+
+call_clause(M:G1, Args, _, G0) :-
+    atom(M),
+    G1 =.. [F | As],
+    atom(F),
+    F \== [],
+    !,
+    append(As, Args, As1),
+    G2 =.. [F | As1],
+    expand_goal(M:G2, M, G0).
+
+call_clause('$call'(G1), Args, N, G0) :-
+    (  var(G1),
+       instantiation_error(call/N)
+    ;  G1 = M:G2,
+       !,
+       atom(M),
+       G2 =.. [F | As],
+       atom(F),
+       F \== [],
+       append(As, Args, As1),
+       G3 =.. [F | As1],
+       G0 = M:G3
+    ;  !,
+       G1 =.. [F | As],
+       atom(F),
+       F \== [],
+       load_context(M),
+       append(As, Args, As1),
+       G2 =.. [F | As1],
+       G0 = M:G2
+    ).
+
+call_clause(G, Args, _, G0) :-
+    G =.. [F | As],
+    atom(F),
+    F \== [],
+    load_context(M),
+    append(As, Args, As1),
+    G2 =.. [F | As1],
+    expand_goal(M:G2, M, G0).
+
+
+call(A,B) :-
+    (  var(A) ->
+       instantiation_error(call/2)
+    ;  (  call_clause(A,[B],2,C) ->
+          '$call'(C)
+       ;  type_error(callable,A,call/2)
+       )
+    ).
+
+call(A,B,C) :-
+    (  var(A) ->
+       instantiation_error(call/3)
+    ;  (  call_clause(A,[B,C],3,D) ->
+          '$call'(D)
+       ;  type_error(callable,A,call/3)
+       )
+    ).
+
+call(A,B,C,D) :-
+    (  var(A) ->
+       instantiation_error(call/4)
+    ;  (  call_clause(A,[B,C,D],4,E) ->
+          '$call'(E)
+       ;  type_error(callable,A,call/4)
+       )
+    ).
+
+call(A,B,C,D,E) :-
+    (  var(A) ->
+       instantiation_error(call/5)
+    ;  (  call_clause(A,[B,C,D,E],5,F) ->
+          '$call'(F)
+       ;  type_error(callable,A,call/5)
+       )
+    ).
+
+call(A,B,C,D,E,F) :-
+    (  var(A) ->
+       instantiation_error(call/6)
+    ;  (  call_clause(A,[B,C,D,E,F],6,G) ->
+          '$call'(G)
+       ;  type_error(callable,A,call/6)
+       )
+    ).
+
+call(A,B,C,D,E,F,G) :-
+    (  var(A) ->
+       instantiation_error(call/7)
+    ;  (  call_clause(A,[B,C,D,E,F,G],7,H) ->
+          '$call'(H)
+       ;  type_error(callable,A,call/7)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H) :-
+    (  var(A) ->
+       instantiation_error(call/8)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H],8,I) ->
+          '$call'(I)
+       ;  type_error(callable,A,call/8)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I) :-
+    (  var(A) ->
+       instantiation_error(call/9)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I],9,J) ->
+          '$call'(J)
+       ;  type_error(callable,A,call/9)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J) :-
+    (  var(A) ->
+       instantiation_error(call/10)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J],10,K) ->
+          '$call'(K)
+       ;  type_error(callable,A,call/10)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K) :-
+    (  var(A) ->
+       instantiation_error(call/11)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K],11,L) ->
+          '$call'(L)
+       ;  type_error(callable,A,call/11)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L) :-
+    (  var(A) ->
+       instantiation_error(call/12)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L],12,M) ->
+          '$call'(M)
+       ;  type_error(callable,A,call/12)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M) :-
+    (  var(A) ->
+       instantiation_error(call/13)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M],13,N) ->
+          '$call'(N)
+       ;  type_error(callable,A,call/13)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N) :-
+    (  var(A) ->
+       instantiation_error(call/14)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N],14,O) ->
+          '$call'(O)
+       ;  type_error(callable,A,call/14)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O) :-
+    (  var(A) ->
+       instantiation_error(call/15)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O],15,P) ->
+          '$call'(P)
+       ;  type_error(callable,A,call/15)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P) :-
+    (  var(A) ->
+       instantiation_error(call/16)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P],16,Q) ->
+          '$call'(Q)
+       ;  type_error(callable,A,call/16)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q) :-
+    (  var(A) ->
+       instantiation_error(call/17)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q],17,R) ->
+          '$call'(R)
+       ;  type_error(callable,A,call/17)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R) :-
+    (  var(A) ->
+       instantiation_error(call/18)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R],18,S) ->
+          '$call'(S)
+       ;  type_error(callable,A,call/18)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S) :-
+    (  var(A) ->
+       instantiation_error(call/19)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S],19,T) ->
+          '$call'(T)
+       ;  type_error(callable,A,call/19)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T) :-
+    (  var(A) ->
+       instantiation_error(call/20)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T],20,U) ->
+          '$call'(U)
+       ;  type_error(callable,A,call/20)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U) :-
+    (  var(A) ->
+       instantiation_error(call/21)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U],21,V) ->
+          '$call'(V)
+       ;  type_error(callable,A,call/21)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V) :-
+    (  var(A) ->
+       instantiation_error(call/22)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V],22,W) ->
+          '$call'(W)
+       ;  type_error(callable,A,call/22)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W) :-
+    (  var(A) ->
+       instantiation_error(call/23)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W],23,X) ->
+          '$call'(X)
+       ;  type_error(callable,A,call/23)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X) :-
+    (  var(A) ->
+       instantiation_error(call/24)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X],24,Y) ->
+          '$call'(Y)
+       ;  type_error(callable,A,call/24)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y) :-
+    (  var(A) ->
+       instantiation_error(call/25)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y],25,Z) ->
+          '$call'(Z)
+       ;  type_error(callable,A,call/25)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z) :-
+    (  var(A) ->
+       instantiation_error(call/26)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z],26,A1) ->
+          '$call'(A1)
+       ;  type_error(callable,A,call/26)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1) :-
+    (  var(A) ->
+       instantiation_error(call/27)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1],27,B1) ->
+          '$call'(B1)
+       ;  type_error(callable,A,call/27)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1) :-
+    (  var(A) ->
+       instantiation_error(call/28)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1],28,C1) ->
+          '$call'(C1)
+       ;  type_error(callable,A,call/28)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1) :-
+    (  var(A) ->
+       instantiation_error(call/29)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1],29,D1) ->
+          '$call'(D1)
+       ;  type_error(callable,A,call/29)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1) :-
+    (  var(A) ->
+       instantiation_error(call/30)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1],30,E1) ->
+          '$call'(E1)
+       ;  type_error(callable,A,call/30)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1) :-
+    (  var(A) ->
+       instantiation_error(call/31)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1],31,F1) ->
+          '$call'(F1)
+       ;  type_error(callable,A,call/31)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1) :-
+    (  var(A) ->
+       instantiation_error(call/32)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1],32,G1) ->
+          '$call'(G1)
+       ;  type_error(callable,A,call/32)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1) :-
+    (  var(A) ->
+       instantiation_error(call/33)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1],33,H1) ->
+          '$call'(H1)
+       ;  type_error(callable,A,call/33)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1) :-
+    (  var(A) ->
+       instantiation_error(call/34)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1],34,I1) ->
+          '$call'(I1)
+       ;  type_error(callable,A,call/34)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1) :-
+    (  var(A) ->
+       instantiation_error(call/35)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1],35,J1) ->
+          '$call'(J1)
+       ;  type_error(callable,A,call/35)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1) :-
+    (  var(A) ->
+       instantiation_error(call/36)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1],36,K1) ->
+          '$call'(K1)
+       ;  type_error(callable,A,call/36)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1) :-
+    (  var(A) ->
+       instantiation_error(call/37)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1],37,L1) ->
+          '$call'(L1)
+       ;  type_error(callable,A,call/37)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1) :-
+    (  var(A) ->
+       instantiation_error(call/38)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1],38,M1) ->
+          '$call'(M1)
+       ;  type_error(callable,A,call/38)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1) :-
+    (  var(A) ->
+       instantiation_error(call/39)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1],39,N1) ->
+          '$call'(N1)
+       ;  type_error(callable,A,call/39)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1) :-
+    (  var(A) ->
+       instantiation_error(call/40)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1],40,O1) ->
+          '$call'(O1)
+       ;  type_error(callable,A,call/40)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1) :-
+    (  var(A) ->
+       instantiation_error(call/41)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1],41,P1) ->
+          '$call'(P1)
+       ;  type_error(callable,A,call/41)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1) :-
+    (  var(A) ->
+       instantiation_error(call/42)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1],42,Q1) ->
+          '$call'(Q1)
+       ;  type_error(callable,A,call/42)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1) :-
+    (  var(A) ->
+       instantiation_error(call/43)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1],43,R1) ->
+          '$call'(R1)
+       ;  type_error(callable,A,call/43)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1) :-
+    (  var(A) ->
+       instantiation_error(call/44)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1],44,S1) ->
+          '$call'(S1)
+       ;  type_error(callable,A,call/44)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1) :-
+    (  var(A) ->
+       instantiation_error(call/45)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1],45,T1) ->
+          '$call'(T1)
+       ;  type_error(callable,A,call/45)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1) :-
+    (  var(A) ->
+       instantiation_error(call/46)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1],46,U1) ->
+          '$call'(U1)
+       ;  type_error(callable,A,call/46)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1) :-
+    (  var(A) ->
+       instantiation_error(call/47)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1],47,V1) ->
+          '$call'(V1)
+       ;  type_error(callable,A,call/47)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1) :-
+    (  var(A) ->
+       instantiation_error(call/48)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1],48,W1) ->
+          '$call'(W1)
+       ;  type_error(callable,A,call/48)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1) :-
+    (  var(A) ->
+       instantiation_error(call/49)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1],49,X1) ->
+          '$call'(X1)
+       ;  type_error(callable,A,call/49)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1) :-
+    (  var(A) ->
+       instantiation_error(call/50)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1],50,Y1) ->
+          '$call'(Y1)
+       ;  type_error(callable,A,call/50)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1) :-
+    (  var(A) ->
+       instantiation_error(call/51)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1],51,Z1) ->
+          '$call'(Z1)
+       ;  type_error(callable,A,call/51)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1) :-
+    (  var(A) ->
+       instantiation_error(call/52)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1],52,A2) ->
+          '$call'(A2)
+       ;  type_error(callable,A,call/52)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2) :-
+    (  var(A) ->
+       instantiation_error(call/53)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2],53,B2) ->
+          '$call'(B2)
+       ;  type_error(callable,A,call/53)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2) :-
+    (  var(A) ->
+       instantiation_error(call/54)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2],54,C2) ->
+          '$call'(C2)
+       ;  type_error(callable,A,call/54)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2) :-
+    (  var(A) ->
+       instantiation_error(call/55)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2],55,D2) ->
+          '$call'(D2)
+       ;  type_error(callable,A,call/55)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2) :-
+    (  var(A) ->
+       instantiation_error(call/56)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2],56,E2) ->
+          '$call'(E2)
+       ;  type_error(callable,A,call/56)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2) :-
+    (  var(A) ->
+       instantiation_error(call/57)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2],57,F2) ->
+          '$call'(F2)
+       ;  type_error(callable,A,call/57)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2) :-
+    (  var(A) ->
+       instantiation_error(call/58)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2],58,G2) ->
+          '$call'(G2)
+       ;  type_error(callable,A,call/58)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2,G2) :-
+    (  var(A) ->
+       instantiation_error(call/59)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2,G2],59,H2) ->
+          '$call'(H2)
+       ;  type_error(callable,A,call/59)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2,G2,H2) :-
+    (  var(A) ->
+       instantiation_error(call/60)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2,G2,H2],60,I2) ->
+          '$call'(I2)
+       ;  type_error(callable,A,call/60)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2,G2,H2,I2) :-
+    (  var(A) ->
+       instantiation_error(call/61)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2,G2,H2,I2],61,J2) ->
+          '$call'(J2)
+       ;  type_error(callable,A,call/61)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2,G2,H2,I2,J2) :-
+    (  var(A) ->
+       instantiation_error(call/62)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2,G2,H2,I2,J2],62,K2) ->
+          '$call'(K2)
+       ;  type_error(callable,A,call/62)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2,G2,H2,I2,J2,K2) :-
+    (  var(A) ->
+       instantiation_error(call/63)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2,G2,H2,I2,J2,K2],63,L2) ->
+          '$call'(L2)
+       ;  type_error(callable,A,call/63)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2,G2,H2,I2,J2,K2,L2) :-
+    (  var(A) ->
+       instantiation_error(call/64)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2,G2,H2,I2,J2,K2,L2],64,M2) ->
+          '$call'(M2)
+       ;  type_error(callable,A,call/64)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2,G2,H2,I2,J2,K2,L2,M2) :-
+    (  var(A) ->
+       instantiation_error(call/65)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2,G2,H2,I2,J2,K2,L2,M2],65,N2) ->
+          '$call'(N2)
+       ;  type_error(callable,A,call/65)
+       )
+    ).
+
+call(A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2,G2,H2,I2,J2,K2,L2,M2) :-
+    (  var(A) ->
+       instantiation_error(call/65)
+    ;  (  call_clause(A,[B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A1,B1,C1,D1,E1,F1,G1,H1,I1,J1,K1,L1,M1,N1,O1,P1,Q1,R1,S1,T1,U1,V1,W1,X1,Y1,Z1,A2,B2,C2,D2,E2,F2,G2,H2,I2,J2,K2,L2,M2],65,N2) ->
+          '$call'(N2)
+       ;  type_error(callable,A,call/65)
+       )
+    ).

src/machine/attributed_variables.pl

@@ -51,7 +51,6 @@ call_goals_0([Module-GoalList | GoalLists]) :-
 call_goals_0([]).
 
 call_goals_1([Goal | Goals], Module) :-
-    expand_goal(Goal, Module, Goal1), % TODO: remove this when goal expansions are added to call/N.
+    call(Module:Goal),
-    call(Module:Goal1),
     call_goals_1(Goals, Module).
 call_goals_1([], _).

src/machine/attributed_variables.rs

@@ -1,7 +1,8 @@
 use crate::heap_iter::*;
 use crate::machine::*;
+use prolog_parser::temp_v;
 
-use crate::indexmap::IndexSet;
+use indexmap::IndexSet;
 
 use std::cmp::Ordering;
 use std::vec::IntoIter;
@@ -20,8 +21,7 @@ pub(super) struct AttrVarInitializer {
 }
 
 impl AttrVarInitializer {
-    pub(super)
+    pub(super) fn new(verify_attrs_loc: usize, project_attrs_loc: usize) -> Self {
-    fn new(verify_attrs_loc: usize, project_attrs_loc: usize) -> Self {
         AttrVarInitializer {
             attribute_goals: vec![],
             attr_var_queue: vec![],
@@ -34,24 +34,21 @@ impl AttrVarInitializer {
     }
 
     #[inline]
-    pub(super)
+    pub(super) fn reset(&mut self) {
-    fn reset(&mut self) {
+        self.attribute_goals.clear();
-	    self.attribute_goals.clear();
         self.attr_var_queue.clear();
         self.bindings.clear();
     }
 
     #[inline]
-    pub(super)
+    pub(super) fn backtrack(&mut self, queue_b: usize, bindings_b: usize) {
-    fn backtrack(&mut self, queue_b: usize, bindings_b: usize) {
         self.attr_var_queue.truncate(queue_b);
         self.bindings.truncate(bindings_b);
     }
 }
 
 impl MachineState {
-    pub(super)
+    pub(super) fn push_attr_var_binding(&mut self, h: usize, addr: Addr) {
-    fn push_attr_var_binding(&mut self, h: usize, addr: Addr) {
         if self.attr_var_init.bindings.is_empty() {
             self.attr_var_init.instigating_p = self.p.local();
 
@@ -79,7 +76,7 @@ impl MachineState {
         let iter = self
             .attr_var_init
             .bindings
-            .drain(0 ..)
+            .drain(0..)
             .map(|(_, addr)| HeapCellValue::Addr(addr));
 
         let value_list_addr = Addr::HeapCell(self.heap.to_list(iter));
@@ -97,8 +94,7 @@ impl MachineState {
         self[temp_v!(2)] = value_list_addr;
     }
 
-    pub(super)
+    pub(super) fn gather_attr_vars_created_since(&self, b: usize) -> IntoIter<Addr> {
-    fn gather_attr_vars_created_since(&self, b: usize) -> IntoIter<Addr> {
         let mut attr_vars: Vec<_> = self.attr_var_init.attr_var_queue[b..]
             .iter()
             .filter_map(|h| match self.store(self.deref(Addr::HeapCell(*h))) {
@@ -107,29 +103,25 @@ impl MachineState {
             })
             .collect();
 
-        attr_vars.sort_unstable_by(|a1, a2| {
+        attr_vars
-            self.compare_term_test(a1, a2).unwrap_or(Ordering::Less)
+            .sort_unstable_by(|a1, a2| self.compare_term_test(a1, a2).unwrap_or(Ordering::Less));
-        });
 
         self.term_dedup(&mut attr_vars);
         attr_vars.into_iter()
     }
 
-    pub(super)
+    pub(super) fn verify_attr_interrupt(&mut self, p: usize) {
-    fn verify_attr_interrupt(&mut self, p: usize) {
         self.allocate(self.num_of_args + 2);
 
         let e = self.e;
         self.stack.index_and_frame_mut(e).prelude.interrupt_cp = self.attr_var_init.cp;
 
-        for i in 1 .. self.num_of_args + 1 {
+        for i in 1..self.num_of_args + 1 {
             self.stack.index_and_frame_mut(e)[i] = self[RegType::Temp(i)];
         }
 
-        self.stack.index_and_frame_mut(e)[self.num_of_args + 1] =
+        self.stack.index_and_frame_mut(e)[self.num_of_args + 1] = Addr::CutPoint(self.b0);
-            Addr::CutPoint(self.b0);
+        self.stack.index_and_frame_mut(e)[self.num_of_args + 2] = Addr::Usize(self.num_of_args);
-        self.stack.index_and_frame_mut(e)[self.num_of_args + 2] =
-            Addr::Usize(self.num_of_args);
 
         self.verify_attributes();
 
@@ -138,9 +130,8 @@ impl MachineState {
         self.p = CodePtr::Local(LocalCodePtr::DirEntry(p));
     }
 
-    pub(super)
+    pub(super) fn attr_vars_of_term(&self, addr: Addr) -> Vec<Addr> {
-    fn attr_vars_of_term(&self, addr: Addr) -> Vec<Addr> {
+        let mut seen_set = IndexSet::new();
-        let mut seen_set  = IndexSet::new();
         let mut seen_vars = vec![];
 
         let mut iter = self.acyclic_pre_order_iter(addr);

src/machine/heap.rs

@@ -1,6 +1,6 @@
 use core::marker::PhantomData;
 
-use crate::prolog_parser_rebis::ast::Constant;
+use prolog_parser::ast::Constant;
 
 use crate::machine::machine_indices::*;
 use crate::machine::partial_string::*;
@@ -42,16 +42,17 @@ impl<T: RawBlockTraits> Drop for HeapTemplate<T> {
 }
 
 #[derive(Debug)]
-pub(crate)
+pub(crate) struct HeapIntoIter<T: RawBlockTraits> {
-struct HeapIntoIter<T: RawBlockTraits> {
     offset: usize,
     buf: RawBlock<T>,
 }
 
 impl<T: RawBlockTraits> Drop for HeapIntoIter<T> {
     fn drop(&mut self) {
-        let mut heap =
+        let mut heap = HeapTemplate {
-            HeapTemplate { buf: self.buf.take(), _marker: PhantomData };
+            buf: self.buf.take(),
+            _marker: PhantomData,
+        };
 
         heap.truncate(self.offset / mem::size_of::<HeapCellValue>());
         heap.buf.deallocate();
@@ -66,9 +67,7 @@ impl<T: RawBlockTraits> Iterator for HeapIntoIter<T> {
         self.offset += mem::size_of::<HeapCellValue>();
 
         if ptr < self.buf.top as usize {
-            unsafe {
+            unsafe { Some(ptr::read(ptr as *const HeapCellValue)) }
-                Some(ptr::read(ptr as *const HeapCellValue))
-            }
         } else {
             None
         }
@@ -76,15 +75,13 @@ impl<T: RawBlockTraits> Iterator for HeapIntoIter<T> {
 }
 
 #[derive(Debug)]
-pub(crate)
+pub(crate) struct HeapIter<'a, T: RawBlockTraits> {
-struct HeapIter<'a, T: RawBlockTraits> {
     offset: usize,
     buf: &'a RawBlock<T>,
 }
 
 impl<'a, T: RawBlockTraits> HeapIter<'a, T> {
-    pub(crate)
+    pub(crate) fn new(buf: &'a RawBlock<T>, offset: usize) -> Self {
-    fn new(buf: &'a RawBlock<T>, offset: usize) -> Self {
         HeapIter { buf, offset }
     }
 }
@@ -97,9 +94,7 @@ impl<'a, T: RawBlockTraits> Iterator for HeapIter<'a, T> {
         self.offset += mem::size_of::<HeapCellValue>();
 
         if ptr < self.buf.top as usize {
-            unsafe {
+            unsafe { Some(&*(ptr as *const _)) }
-                Some(&*(ptr as *const _))
-            }
         } else {
             None
         }
@@ -107,23 +102,20 @@ impl<'a, T: RawBlockTraits> Iterator for HeapIter<'a, T> {
 }
 
 #[allow(dead_code)]
-pub(crate)
+pub(crate) fn print_heap_terms<'a, I: Iterator<Item = &'a HeapCellValue>>(heap: I, h: usize) {
-fn print_heap_terms<'a, I: Iterator<Item = &'a HeapCellValue>>(heap: I, h: usize) {
     for (index, term) in heap.enumerate() {
         println!("{} : {}", h + index, term);
     }
 }
 
 #[derive(Debug)]
-pub(crate)
+pub(crate) struct HeapIterMut<'a, T: RawBlockTraits> {
-struct HeapIterMut<'a, T: RawBlockTraits> {
     offset: usize,
     buf: &'a mut RawBlock<T>,
 }
 
 impl<'a, T: RawBlockTraits> HeapIterMut<'a, T> {
-    pub(crate)
+    pub(crate) fn new(buf: &'a mut RawBlock<T>, offset: usize) -> Self {
-    fn new(buf: &'a mut RawBlock<T>, offset: usize) -> Self {
         HeapIterMut { buf, offset }
     }
 }
@@ -136,9 +128,7 @@ impl<'a, T: RawBlockTraits> Iterator for HeapIterMut<'a, T> {
         self.offset += mem::size_of::<HeapCellValue>();
 
         if ptr < self.buf.top as usize {
-            unsafe {
+            unsafe { Some(&mut *(ptr as *mut _)) }
-                Some(&mut *(ptr as *mut _))
-            }
         } else {
             None
         }
@@ -147,51 +137,33 @@ impl<'a, T: RawBlockTraits> Iterator for HeapIterMut<'a, T> {
 
 impl<T: RawBlockTraits> HeapTemplate<T> {
     #[inline]
-    pub(crate)
+    pub(crate) fn new() -> Self {
-    fn new() -> Self {
+        HeapTemplate {
-        HeapTemplate { buf: RawBlock::new(), _marker: PhantomData }
+            buf: RawBlock::new(),
-    }
+            _marker: PhantomData,
-
-    #[inline]
-    pub(crate)
-    fn clone(&self, h: usize) -> HeapCellValue {
-        match &self[h] {
-            &HeapCellValue::Addr(addr) => {
-                HeapCellValue::Addr(addr)
-            }
-            &HeapCellValue::Atom(ref name, ref op) => {
-                HeapCellValue::Atom(name.clone(), op.clone())
-            }
-            &HeapCellValue::DBRef(ref db_ref) => {
-                HeapCellValue::DBRef(db_ref.clone())
-            }
-            &HeapCellValue::Integer(ref n) => {
-                HeapCellValue::Integer(n.clone())
-            }
-            &HeapCellValue::LoadStatePayload(_) => {
-                HeapCellValue::Addr(Addr::LoadStatePayload(h))
-            }
-            &HeapCellValue::NamedStr(arity, ref name, ref op) => {
-                HeapCellValue::NamedStr(arity, name.clone(), op.clone())
-            }
-            &HeapCellValue::PartialString(..) => {
-                HeapCellValue::Addr(Addr::PStrLocation(h, 0))
-            }
-            &HeapCellValue::Rational(ref r) => {
-                HeapCellValue::Rational(r.clone())
-            }
-            &HeapCellValue::Stream(_) => {
-                HeapCellValue::Addr(Addr::Stream(h))
-            }
-            &HeapCellValue::TcpListener(_) => {
-                HeapCellValue::Addr(Addr::TcpListener(h))
-            }
         }
     }
 
     #[inline]
-    pub(crate)
+    pub(crate) fn clone(&self, h: usize) -> HeapCellValue {
-    fn put_complete_string(&mut self, s: &str) -> Addr {
+        match &self[h] {
+            &HeapCellValue::Addr(addr) => HeapCellValue::Addr(addr),
+            &HeapCellValue::Atom(ref name, ref op) => HeapCellValue::Atom(name.clone(), op.clone()),
+            &HeapCellValue::DBRef(ref db_ref) => HeapCellValue::DBRef(db_ref.clone()),
+            &HeapCellValue::Integer(ref n) => HeapCellValue::Integer(n.clone()),
+            &HeapCellValue::LoadStatePayload(_) => HeapCellValue::Addr(Addr::LoadStatePayload(h)),
+            &HeapCellValue::NamedStr(arity, ref name, ref op) => {
+                HeapCellValue::NamedStr(arity, name.clone(), op.clone())
+            }
+            &HeapCellValue::PartialString(..) => HeapCellValue::Addr(Addr::PStrLocation(h, 0)),
+            &HeapCellValue::Rational(ref r) => HeapCellValue::Rational(r.clone()),
+            &HeapCellValue::Stream(_) => HeapCellValue::Addr(Addr::Stream(h)),
+            &HeapCellValue::TcpListener(_) => HeapCellValue::Addr(Addr::TcpListener(h)),
+        }
+    }
+
+    #[inline]
+    pub(crate) fn put_complete_string(&mut self, s: &str) -> Addr {
         if s.is_empty() {
             return Addr::EmptyList;
         }
@@ -214,30 +186,15 @@ impl<T: RawBlockTraits> HeapTemplate<T> {
     }
 
     #[inline]
-    pub(crate)
+    pub(crate) fn put_constant(&mut self, c: Constant) -> Addr {
-    fn put_constant(&mut self, c: Constant) -> Addr {
         match c {
-            Constant::Atom(name, op) => {
+            Constant::Atom(name, op) => Addr::Con(self.push(HeapCellValue::Atom(name, op))),
-                Addr::Con(self.push(HeapCellValue::Atom(name, op)))
+            Constant::Char(c) => Addr::Char(c),
-            }
+            Constant::EmptyList => Addr::EmptyList,
-            Constant::Char(c) => {
+            Constant::Fixnum(n) => Addr::Fixnum(n),
-                Addr::Char(c)
+            Constant::Integer(n) => Addr::Con(self.push(HeapCellValue::Integer(n))),
-            }
+            Constant::Rational(r) => Addr::Con(self.push(HeapCellValue::Rational(r))),
-            Constant::EmptyList => {
+            Constant::Float(f) => Addr::Float(f),
-                Addr::EmptyList
-            }
-            Constant::Fixnum(n) => {
-                Addr::Fixnum(n)
-            }
-            Constant::Integer(n) => {
-                Addr::Con(self.push(HeapCellValue::Integer(n)))
-            }
-            Constant::Rational(r) => {
-                Addr::Con(self.push(HeapCellValue::Rational(r)))
-            }
-            Constant::Float(f) => {
-                Addr::Float(f)
-            }
             Constant::String(s) => {
                 if s.is_empty() {
                     Addr::EmptyList
@@ -245,15 +202,12 @@ impl<T: RawBlockTraits> HeapTemplate<T> {
                     self.put_complete_string(&s)
                 }
             }
-            Constant::Usize(n) => {
+            Constant::Usize(n) => Addr::Usize(n),
-                Addr::Usize(n)
-            }
         }
     }
 
     #[inline]
-    pub(crate)
+    pub(crate) fn pop(&mut self) {
-    fn pop(&mut self) {
         let h = self.h();
 
         if h > 0 {
@@ -262,8 +216,7 @@ impl<T: RawBlockTraits> HeapTemplate<T> {
     }
 
     #[inline]
-    pub(crate)
+    pub(crate) fn push(&mut self, val: HeapCellValue) -> usize {
-    fn push(&mut self, val: HeapCellValue) -> usize {
         let h = self.h();
 
         unsafe {
@@ -276,8 +229,7 @@ impl<T: RawBlockTraits> HeapTemplate<T> {
     }
 
     #[inline]
-    pub(crate)
+    pub(crate) fn atom_at(&self, h: usize) -> bool {
-    fn atom_at(&self, h: usize) -> bool {
         if let HeapCellValue::Atom(..) = &self[h] {
             true
         } else {
@@ -286,24 +238,15 @@ impl<T: RawBlockTraits> HeapTemplate<T> {
     }
 
     #[inline]
-    pub(crate)
+    pub(crate) fn to_unifiable(&mut self, non_heap_value: HeapCellValue) -> Addr {
-    fn to_unifiable(&mut self, non_heap_value: HeapCellValue) -> Addr {
         match non_heap_value {
-            HeapCellValue::Addr(addr) => {
+            HeapCellValue::Addr(addr) => addr,
-                addr
+            val @ HeapCellValue::Atom(..)
-            }
+            | val @ HeapCellValue::Integer(_)
-            val @ HeapCellValue::Atom(..) |
+            | val @ HeapCellValue::DBRef(_)
-            val @ HeapCellValue::Integer(_) |
+            | val @ HeapCellValue::Rational(_) => Addr::Con(self.push(val)),
-            val @ HeapCellValue::DBRef(_) |
+            val @ HeapCellValue::LoadStatePayload(_) => Addr::LoadStatePayload(self.push(val)),
-            val @ HeapCellValue::Rational(_) => {
+            val @ HeapCellValue::NamedStr(..) => Addr::Str(self.push(val)),
-                Addr::Con(self.push(val))
-            }
-            val @ HeapCellValue::LoadStatePayload(_) => {
-                Addr::LoadStatePayload(self.push(val))
-            }
-            val @ HeapCellValue::NamedStr(..) => {
-                Addr::Str(self.push(val))
-            }
             HeapCellValue::PartialString(pstr, has_tail) => {
                 let h = self.push(HeapCellValue::PartialString(pstr, has_tail));
 
@@ -313,20 +256,14 @@ impl<T: RawBlockTraits> HeapTemplate<T> {
 
                 Addr::Con(h)
             }
-            val @ HeapCellValue::Stream(..) => {
+            val @ HeapCellValue::Stream(..) => Addr::Stream(self.push(val)),
-                Addr::Stream(self.push(val))
+            val @ HeapCellValue::TcpListener(..) => Addr::TcpListener(self.push(val)),
-            }
-            val @ HeapCellValue::TcpListener(..) => {
-                Addr::TcpListener(self.push(val))
-            }
         }
     }
 
     #[inline]
-    pub(crate)
+    pub(crate) fn allocate_pstr(&mut self, src: &str) -> Addr {
-    fn allocate_pstr(&mut self, src: &str) -> Addr {
+        self.write_pstr(src).unwrap_or_else(|| Addr::EmptyList)
-        self.write_pstr(src)
-            .unwrap_or_else(|| Addr::EmptyList)
     }
 
     #[inline]
@@ -347,23 +284,20 @@ impl<T: RawBlockTraits> HeapTemplate<T> {
 
             let h = self.h();
 
-            let (pstr, rest_src) =
+            let (pstr, rest_src) = match PartialString::new(src) {
-                match PartialString::new(src) {
+                Some(tuple) => tuple,
-                    Some(tuple) => {
+                None => {
-                        tuple
+                    if src.len() > '\u{0}'.len_utf8() {
+                        src = &src['\u{0}'.len_utf8()..];
+                        continue;
+                    } else if orig_h == h {
+                        return None;
+                    } else {
+                        self[h - 1] = HeapCellValue::Addr(Addr::HeapCell(h - 1));
+                        return Some(Addr::PStrLocation(orig_h, 0));
                     }
-                    None => {
+                }
-                        if src.len() > '\u{0}'.len_utf8() {
+            };
-                            src = &src['\u{0}'.len_utf8() ..];
-                            continue;
-                        } else if orig_h == h {
-                            return None;
-                        } else {
-                            self[h - 1] = HeapCellValue::Addr(Addr::HeapCell(h - 1));
-                            return Some(Addr::PStrLocation(orig_h, 0));
-                        }
-                    }
-                };
 
             self.push(HeapCellValue::PartialString(pstr, true));
 
@@ -378,8 +312,7 @@ impl<T: RawBlockTraits> HeapTemplate<T> {
     }
 
     #[inline]
-    pub(crate)
+    pub(crate) fn truncate(&mut self, h: usize) {
-    fn truncate(&mut self, h: usize) {
         let new_top = h * mem::size_of::<HeapCellValue>() + self.buf.base as usize;
         let mut h = new_top;
 
@@ -395,30 +328,27 @@ impl<T: RawBlockTraits> HeapTemplate<T> {
     }
 
     #[inline]
-    pub(crate)
+    pub(crate) fn h(&self) -> usize {
-    fn h(&self) -> usize {
         (self.buf.top as usize - self.buf.base as usize) / mem::size_of::<HeapCellValue>()
     }
 
-    pub(crate)
+    pub(crate) fn append(&mut self, vals: Vec<HeapCellValue>) {
-    fn append(&mut self, vals: Vec<HeapCellValue>) {
         for val in vals {
             self.push(val);
         }
     }
 
-    pub(crate)
+    pub(crate) fn clear(&mut self) {
-    fn clear(&mut self) {
         if !self.buf.base.is_null() {
             self.truncate(0);
             self.buf.top = self.buf.base;
         }
     }
 
-    pub(crate)
+    pub(crate) fn to_list<Iter, SrcT>(&mut self, values: Iter) -> usize
-    fn to_list<Iter, SrcT>(&mut self, values: Iter) -> usize
+    where
-        where Iter: Iterator<Item = SrcT>,
+        Iter: Iterator<Item = SrcT>,
-              SrcT: Into<HeapCellValue>
+        SrcT: Into<HeapCellValue>,
     {
         let head_addr = self.h();
         let mut h = head_addr;
@@ -436,35 +366,33 @@ impl<T: RawBlockTraits> HeapTemplate<T> {
     }
 
     /* Create an iterator starting from the passed offset. */
-    pub(crate)
+    pub(crate) fn iter_from<'a>(&'a self, offset: usize) -> HeapIter<'a, T> {
-    fn iter_from<'a>(&'a self, offset: usize) -> HeapIter<'a, T> {
         HeapIter::new(&self.buf, offset * mem::size_of::<HeapCellValue>())
     }
 
-    pub(crate)
+    pub(crate) fn iter_mut_from<'a>(&'a mut self, offset: usize) -> HeapIterMut<'a, T> {
-    fn iter_mut_from<'a>(&'a mut self, offset: usize) -> HeapIterMut<'a, T> {
         HeapIterMut::new(&mut self.buf, offset * mem::size_of::<HeapCellValue>())
     }
 
-    pub(crate)
+    pub(crate) fn into_iter(mut self) -> HeapIntoIter<T> {
-    fn into_iter(mut self) -> HeapIntoIter<T> {
+        HeapIntoIter {
-        HeapIntoIter { buf: self.buf.take(), offset: 0 }
+            buf: self.buf.take(),
+            offset: 0,
+        }
     }
 
-    pub(crate)
+    pub(crate) fn extend<Iter: Iterator<Item = HeapCellValue>>(&mut self, iter: Iter) {
-    fn extend<Iter: Iterator<Item = HeapCellValue>>(&mut self, iter: Iter) {
         for hcv in iter {
             self.push(hcv);
         }
     }
 
-    pub(crate)
+    pub(crate) fn to_local_code_ptr(&self, addr: &Addr) -> Option<LocalCodePtr> {
-    fn to_local_code_ptr(&self, addr: &Addr) -> Option<LocalCodePtr> {
         let extract_integer = |s: usize| -> Option<usize> {
             match &self[s] {
                 &HeapCellValue::Addr(Addr::Fixnum(n)) => usize::try_from(n).ok(),
                 &HeapCellValue::Integer(ref n) => n.to_usize(),
-                _ => None
+                _ => None,
             }
         };
 
@@ -473,9 +401,7 @@ impl<T: RawBlockTraits> HeapTemplate<T> {
                 match &self[*s] {
                     HeapCellValue::NamedStr(arity, ref name, _) => {
                         match (name.as_str(), *arity) {
-                            ("dir_entry", 1) => {
+                            ("dir_entry", 1) => extract_integer(s + 1).map(LocalCodePtr::DirEntry),
-                                extract_integer(s+1).map(LocalCodePtr::DirEntry)
-                            }
                             /*
                             ("top_level", 2) => {
                                 if let Some(chunk_num) = extract_integer(s+1) {
@@ -487,15 +413,13 @@ impl<T: RawBlockTraits> HeapTemplate<T> {
                                 None
                             }
                             */
-                            _ => {
+                            _ => None,
-                                None
-                            }
                         }
                     }
-                    _ => unreachable!()
+                    _ => unreachable!(),
                 }
             }
-            _ => None
+            _ => None,
         }
     }
 
@@ -505,9 +429,7 @@ impl<T: RawBlockTraits> HeapTemplate<T> {
             &Addr::Con(h) | &Addr::Str(h) | &Addr::Stream(h) | &Addr::TcpListener(h) => {
                 RefOrOwned::Borrowed(&self[h])
             }
-            addr => {
+            addr => RefOrOwned::Owned(HeapCellValue::Addr(*addr)),
-                RefOrOwned::Owned(HeapCellValue::Addr(*addr))
-            }
         }
     }
 }

src/machine/load_state.rs

@@ -1,10 +1,11 @@
-use crate::machine::*;
 use crate::machine::machine_indices::*;
-use crate::machine::term_stream::*;
+use crate::machine::*;
+use prolog_parser::clause_name;
 
+use crate::machine::term_stream::*;
 use indexmap::IndexSet;
 
-use crate::ref_thread_local::RefThreadLocal;
+use ref_thread_local::RefThreadLocal;
 
 type ModuleOpExports = Vec<(OpDecl, Option<(usize, Specifier)>)>;
 
@@ -19,37 +20,35 @@ pub(super) struct LoadState<'a> {
     pub(super) wam: &'a mut Machine,
 }
 
-pub(super)
+pub(super) fn set_code_index(
-fn set_code_index(
     retraction_info: &mut RetractionInfo,
     compilation_target: &CompilationTarget,
     key: PredicateKey,
     code_index: &CodeIndex,
     code_ptr: IndexPtr,
 ) {
-    let record =
+    let record = match compilation_target {
-        match compilation_target {
+        CompilationTarget::User => {
-            CompilationTarget::User => {
+            if IndexPtr::Undefined == code_index.get() {
-                if IndexPtr::Undefined == code_index.get() {
+                code_index.set(code_ptr);
-                    code_index.set(code_ptr);
+                RetractionRecord::AddedUserPredicate(key)
-                    RetractionRecord::AddedUserPredicate(key)
+            } else {
-                } else {
+                // TODO: emit warning about overwriting previous record
-                    // TODO: emit warning about overwriting previous record
+                let replaced = code_index.replace(code_ptr);
-                    let replaced = code_index.replace(code_ptr);
+                RetractionRecord::ReplacedUserPredicate(key, replaced)
-                    RetractionRecord::ReplacedUserPredicate(key, replaced)
-                }
             }
-            CompilationTarget::Module(ref module_name) => {
+        }
-                if IndexPtr::Undefined == code_index.get() {
+        CompilationTarget::Module(ref module_name) => {
-                    code_index.set(code_ptr);
+            if IndexPtr::Undefined == code_index.get() {
-                    RetractionRecord::AddedModulePredicate(module_name.clone(), key)
+                code_index.set(code_ptr);
-                } else {
+                RetractionRecord::AddedModulePredicate(module_name.clone(), key)
-                    // TODO: emit warning about overwriting previous record
+            } else {
-                    let replaced = code_index.replace(code_ptr);
+                // TODO: emit warning about overwriting previous record
-                    RetractionRecord::ReplacedModulePredicate(module_name.clone(), key, replaced)
+                let replaced = code_index.replace(code_ptr);
-                }
+                RetractionRecord::ReplacedModulePredicate(module_name.clone(), key, replaced)
             }
-        };
+        }
+    };
 
     retraction_info.push_record(record);
 }
@@ -71,17 +70,16 @@ fn add_op_decl_as_module_export(
 
     match op_decl.insert_into_op_dir(wam_op_dir) {
         Some((prec, spec)) => {
-            retraction_info.push_record(
+            retraction_info.push_record(RetractionRecord::ReplacedUserOp(
-                RetractionRecord::ReplacedUserOp(op_decl.clone(), prec, spec)
+                op_decl.clone(),
-            );
+                prec,
+                spec,
+            ));
 
             module_op_exports.push((op_decl.clone(), Some((prec, spec))));
         }
         None => {
-            retraction_info.push_record(
+            retraction_info.push_record(RetractionRecord::AddedUserOp(op_decl.clone()));
-                RetractionRecord::AddedUserOp(op_decl.clone())
-            );
-
             module_op_exports.push((op_decl.clone(), None));
         }
     }
@@ -89,56 +87,52 @@ fn add_op_decl_as_module_export(
     add_op_decl(retraction_info, compilation_target, module_op_dir, op_decl);
 }
 
-pub(super)
+pub(super) fn add_op_decl(
-fn add_op_decl(
     retraction_info: &mut RetractionInfo,
     compilation_target: &CompilationTarget,
     op_dir: &mut OpDir,
     op_decl: &OpDecl,
 ) {
     match op_decl.insert_into_op_dir(op_dir) {
-        Some((prec, spec)) => {
+        Some((prec, spec)) => match &compilation_target {
-            match &compilation_target {
+            CompilationTarget::User => {
-                CompilationTarget::User => {
+                retraction_info.push_record(RetractionRecord::ReplacedUserOp(
-                    retraction_info.push_record(
+                    op_decl.clone(),
-                        RetractionRecord::ReplacedUserOp(op_decl.clone(), prec, spec),
+                    prec,
-                    );
+                    spec,
-                }
+                ));
-                CompilationTarget::Module(ref module_name) => {
-                    retraction_info.push_record(
-                        RetractionRecord::ReplacedModuleOp(
-                            module_name.clone(), op_decl.clone(), prec, spec,
-                        ),
-                    );
-                }
             }
-        }
+            CompilationTarget::Module(ref module_name) => {
-        None => {
+                retraction_info.push_record(RetractionRecord::ReplacedModuleOp(
-            match &compilation_target {
+                    module_name.clone(),
-                CompilationTarget::User => {
+                    op_decl.clone(),
-                    retraction_info.push_record(
+                    prec,
-                        RetractionRecord::AddedUserOp(op_decl.clone()),
+                    spec,
-                    );
+                ));
-                }
-                CompilationTarget::Module(ref module_name) => {
-                    retraction_info.push_record(
-                        RetractionRecord::AddedModuleOp(module_name.clone(), op_decl.clone()),
-                    );
-                }
             }
-        }
+        },
+        None => match &compilation_target {
+            CompilationTarget::User => {
+                retraction_info.push_record(RetractionRecord::AddedUserOp(op_decl.clone()));
+            }
+            CompilationTarget::Module(ref module_name) => {
+                retraction_info.push_record(RetractionRecord::AddedModuleOp(
+                    module_name.clone(),
+                    op_decl.clone(),
+                ));
+            }
+        },
     }
 }
 
-pub(super)
+pub(super) fn import_module_exports(
-fn import_module_exports(
     retraction_info: &mut RetractionInfo,
     compilation_target: &CompilationTarget,
     imported_module: &Module,
     code_dir: &mut CodeDir,
     op_dir: &mut OpDir,
     meta_predicates: &mut MetaPredicateDir,
-) {
+) -> Result<(), SessionError> {
     for export in imported_module.module_decl.exports.iter() {
         match export {
             ModuleExport::PredicateKey((ref name, arity)) => {
@@ -162,19 +156,19 @@ fn import_module_exports(
                         src_code_index.get(),
                     );
                 } else {
-                    unreachable!()
+                    return Err(SessionError::ModuleDoesNotContainExport(
+                        imported_module.module_decl.name.clone(),
+                        (name.clone(), *arity),
+                    ));
                 }
             }
             ModuleExport::OpDecl(ref op_decl) => {
-                add_op_decl(
+                add_op_decl(retraction_info, compilation_target, op_dir, op_decl);
-                    retraction_info,
-                    compilation_target,
-                    op_dir,
-                    op_decl,
-                );
             }
         }
     }
+
+    Ok(())
 }
 
 fn import_module_exports_into_module(
@@ -185,8 +179,8 @@ fn import_module_exports_into_module(
     op_dir: &mut OpDir,
     meta_predicates: &mut MetaPredicateDir,
     wam_op_dir: &mut OpDir,
-    module_op_exports: &mut ModuleOpExports
+    module_op_exports: &mut ModuleOpExports,
-) {
+) -> Result<(), SessionError> {
     for export in imported_module.module_decl.exports.iter() {
         match export {
             ModuleExport::PredicateKey((ref name, arity)) => {
@@ -210,7 +204,10 @@ fn import_module_exports_into_module(
                         src_code_index.get(),
                     );
                 } else {
-                    unreachable!()
+                    return Err(SessionError::ModuleDoesNotContainExport(
+                        imported_module.module_decl.name.clone(),
+                        (name.clone(), *arity),
+                    ));
                 }
             }
             ModuleExport::OpDecl(ref op_decl) => {
@@ -225,8 +222,9 @@ fn import_module_exports_into_module(
             }
         }
     }
-}
 
+    Ok(())
+}
 
 fn import_qualified_module_exports(
     retraction_info: &mut RetractionInfo,
@@ -235,7 +233,7 @@ fn import_qualified_module_exports(
     exports: &IndexSet<ModuleExport>,
     code_dir: &mut CodeDir,
     op_dir: &mut OpDir,
-) {
+) -> Result<(), SessionError> {
     for export in imported_module.module_decl.exports.iter() {
         if !exports.contains(export) {
             continue;
@@ -259,19 +257,19 @@ fn import_qualified_module_exports(
                         src_code_index.get(),
                     );
                 } else {
-                    unreachable!()
+                    return Err(SessionError::ModuleDoesNotContainExport(
+                        imported_module.module_decl.name.clone(),
+                        (name.clone(), *arity),
+                    ));
                 }
             }
             ModuleExport::OpDecl(ref op_decl) => {
-                add_op_decl(
+                add_op_decl(retraction_info, compilation_target, op_dir, op_decl);
-                    retraction_info,
-                    compilation_target,
-                    op_dir,
-                    op_decl,
-                );
             }
         }
     }
+
+    Ok(())
 }
 
 fn import_qualified_module_exports_into_module(
@@ -283,7 +281,7 @@ fn import_qualified_module_exports_into_module(
     op_dir: &mut OpDir,
     wam_op_dir: &mut OpDir,
     module_op_exports: &mut ModuleOpExports,
-) {
+) -> Result<(), SessionError> {
     for export in imported_module.module_decl.exports.iter() {
         if !exports.contains(export) {
             continue;
@@ -307,7 +305,10 @@ fn import_qualified_module_exports_into_module(
                         src_code_index.get(),
                     );
                 } else {
-                    unreachable!()
+                    return Err(SessionError::ModuleDoesNotContainExport(
+                        imported_module.module_decl.name.clone(),
+                        (name.clone(), *arity),
+                    ));
                 }
             }
             ModuleExport::OpDecl(ref op_decl) => {
@@ -322,33 +323,34 @@ fn import_qualified_module_exports_into_module(
             }
         }
     }
+
+    Ok(())
 }
 
 impl<'a> LoadState<'a> {
     #[inline]
-    pub(super)
+    pub(super) fn increment_clause_assert_margin(&mut self, incr: usize) {
-    fn increment_clause_assert_margin(&mut self, incr: usize) {
         match &self.compilation_target {
-            CompilationTarget::User => {
+            CompilationTarget::User => {}
-            }
             CompilationTarget::Module(ref module_name) => {
-                self.retraction_info.push_record(
+                self.retraction_info
-                    RetractionRecord::IncreasedClauseAssertMargin(
+                    .push_record(RetractionRecord::IncreasedClauseAssertMargin(
                         module_name.clone(),
                         incr,
-                    ),
+                    ));
-                );
 
-                self.wam.indices.modules.get_mut(module_name)
+                self.wam
+                    .indices
+                    .modules
+                    .get_mut(module_name)
                     .map(|module| module.clause_assert_margin += incr);
             }
         }
     }
 
     #[inline]
-    pub(super)
+    pub(super) fn remove_module_op_exports(&mut self) {
-    fn remove_module_op_exports(&mut self) {
+        for (mut op_decl, record) in self.module_op_exports.drain(0..) {
-        for (mut op_decl, record) in self.module_op_exports.drain(0 ..) {
             op_decl.remove(&mut self.wam.indices.op_dir);
 
             if let Some((prec, spec)) = record {
@@ -365,26 +367,28 @@ impl<'a> LoadState<'a> {
         key: PredicateKey,
     ) -> CodeIndex {
         match self.wam.indices.modules.get_mut(&module_name) {
-            Some(ref mut module) => {
+            Some(ref mut module) => module
-                module.code_dir
+                .code_dir
-                    .entry(key)
+                .entry(key)
-                    .or_insert_with(|| CodeIndex::new(IndexPtr::Undefined))
+                .or_insert_with(|| CodeIndex::new(IndexPtr::Undefined))
-                    .clone()
+                .clone(),
-            }
             None => {
                 let mut module = Module::new(
-                    ModuleDecl { name: module_name.clone(), exports: vec![] },
+                    ModuleDecl {
+                        name: module_name.clone(),
+                        exports: vec![],
+                    },
                     ListingSource::DynamicallyGenerated,
                 );
 
-                let code_index = module.code_dir
+                let code_index = module
+                    .code_dir
                     .entry(key)
                     .or_insert_with(|| CodeIndex::new(IndexPtr::Undefined))
                     .clone();
 
-                self.retraction_info.push_record(
+                self.retraction_info
-                    RetractionRecord::AddedModule(module_name.clone()),
+                    .push_record(RetractionRecord::AddedModule(module_name.clone()));
-                );
 
                 self.wam.indices.modules.insert(module_name, module);
                 code_index
@@ -392,29 +396,31 @@ impl<'a> LoadState<'a> {
         }
     }
 
-    pub(super)
+    pub(super) fn get_or_insert_code_index(&mut self, key: PredicateKey) -> CodeIndex {
-    fn get_or_insert_code_index(&mut self, key: PredicateKey) -> CodeIndex {
         match self.compilation_target.clone() {
-            CompilationTarget::User => {
+            CompilationTarget::User => self
-                self.wam.indices.code_dir
+                .wam
-                    .entry(key)
+                .indices
-                    .or_insert_with(|| CodeIndex::new(IndexPtr::Undefined))
+                .code_dir
-                    .clone()
+                .entry(key)
-            }
+                .or_insert_with(|| CodeIndex::new(IndexPtr::Undefined))
+                .clone(),
             CompilationTarget::Module(module_name) => {
                 self.get_or_insert_local_code_index(module_name, key)
             }
         }
     }
 
-    pub(super)
+    pub(super) fn get_or_insert_qualified_code_index(
-    fn get_or_insert_qualified_code_index(
         &mut self,
         module_name: ClauseName,
         key: PredicateKey,
     ) -> CodeIndex {
         if module_name.as_str() == "user" {
-            return self.wam.indices.code_dir
+            return self
+                .wam
+                .indices
+                .code_dir
                 .entry(key)
                 .or_insert_with(|| CodeIndex::new(IndexPtr::Undefined))
                 .clone();
@@ -424,15 +430,20 @@ impl<'a> LoadState<'a> {
     }
 
     #[inline]
-    pub(super)
+    pub(super) fn add_extensible_predicate(
-    fn add_extensible_predicate(&mut self, key: PredicateKey, skeleton: PredicateSkeleton) {
+        &mut self,
+        key: PredicateKey,
+        skeleton: PredicateSkeleton,
+    ) {
         match &self.compilation_target {
             CompilationTarget::User => {
-                self.wam.indices.extensible_predicates.insert(key.clone(), skeleton);
+                self.wam
+                    .indices
+                    .extensible_predicates
+                    .insert(key.clone(), skeleton);
 
-                self.retraction_info.push_record(
+                self.retraction_info
-                    RetractionRecord::AddedUserExtensiblePredicate(key),
+                    .push_record(RetractionRecord::AddedUserExtensiblePredicate(key));
-                );
             }
             CompilationTarget::Module(ref module_name) => {
                 if let Some(module) = self.wam.indices.modules.get_mut(module_name) {
@@ -448,8 +459,7 @@ impl<'a> LoadState<'a> {
         }
     }
 
-    pub(super)
+    pub(super) fn add_op_decl(&mut self, op_decl: &OpDecl) {
-    fn add_op_decl(&mut self, op_decl: &OpDecl) {
         match &self.compilation_target {
             CompilationTarget::User => {
                 add_op_decl(
@@ -479,8 +489,7 @@ impl<'a> LoadState<'a> {
         }
     }
 
-    pub(super)
+    pub(super) fn get_clause_type(
-    fn get_clause_type(
         &mut self,
         name: ClauseName,
         arity: usize,
@@ -495,14 +504,11 @@ impl<'a> LoadState<'a> {
                 let idx = self.get_or_insert_code_index((name.clone(), arity));
                 ClauseType::Op(name, fixity, idx)
             }
-            ct => {
+            ct => ct,
-                ct
-            }
         }
     }
 
-    pub(super)
+    pub(super) fn get_qualified_clause_type(
-    fn get_qualified_clause_type(
         &mut self,
         module_name: ClauseName,
         name: ClauseName,
@@ -522,27 +528,11 @@ impl<'a> LoadState<'a> {
 
                 ClauseType::Op(name, fixity, idx)
             }
-            ct => {
+            ct => ct,
-                ct
-            }
         }
     }
 
-    #[inline]
+    pub(super) fn add_meta_predicate_record(
-    pub(super)
-    fn module_name(&self) -> ClauseName {
-        match self.compilation_target {
-            CompilationTarget::User => {
-                clause_name!("user")
-            }
-            CompilationTarget::Module(ref module_name) => {
-                module_name.clone()
-            }
-        }
-    }
-
-    pub(super)
-    fn add_meta_predicate_record(
         &mut self,
         module_name: ClauseName,
         name: ClauseName,
@@ -553,20 +543,26 @@ impl<'a> LoadState<'a> {
 
         match module_name.as_str() {
             "user" => {
-                match self.wam.indices.meta_predicates.insert(key.clone(), meta_specs) {
+                match self
+                    .wam
+                    .indices
+                    .meta_predicates
+                    .insert(key.clone(), meta_specs)
+                {
                     Some(old_meta_specs) => {
-                        self.retraction_info.push_record(
+                        self.retraction_info
-                            RetractionRecord::ReplacedMetaPredicate(
+                            .push_record(RetractionRecord::ReplacedMetaPredicate(
-                                module_name.clone(), key.0, old_meta_specs,
+                                module_name.clone(),
-                            ),
+                                key.0,
-                        );
+                                old_meta_specs,
+                            ));
                     }
                     None => {
-                        self.retraction_info.push_record(
+                        self.retraction_info
-                            RetractionRecord::AddedMetaPredicate(
+                            .push_record(RetractionRecord::AddedMetaPredicate(
-                                module_name.clone(), key,
+                                module_name.clone(),
-                            )
+                                key,
-                        );
+                            ));
                     }
                 }
             }
@@ -577,15 +573,15 @@ impl<'a> LoadState<'a> {
                             Some(old_meta_specs) => {
                                 self.retraction_info.push_record(
                                     RetractionRecord::ReplacedMetaPredicate(
-                                        module_name.clone(), key.0, old_meta_specs,
+                                        module_name.clone(),
+                                        key.0,
+                                        old_meta_specs,
                                     ),
                                 );
                             }
                             None => {
                                 self.retraction_info.push_record(
-                                    RetractionRecord::AddedMetaPredicate(
+                                    RetractionRecord::AddedMetaPredicate(module_name.clone(), key),
-                                        module_name.clone(), key,
-                                    )
                                 );
                             }
                         }
@@ -601,15 +597,14 @@ impl<'a> LoadState<'a> {
 
                         module.meta_predicates.insert(key.clone(), meta_specs);
 
-                        self.retraction_info.push_record(
+                        self.retraction_info
-                            RetractionRecord::AddedMetaPredicate(
+                            .push_record(RetractionRecord::AddedMetaPredicate(
-                                module_name.clone(), key,
+                                module_name.clone(),
-                            )
+                                key,
-                        );
+                            ));
 
-                        self.retraction_info.push_record(
+                        self.retraction_info
-                            RetractionRecord::AddedModule(module_name.clone()),
+                            .push_record(RetractionRecord::AddedModule(module_name.clone()));
-                        );
 
                         self.wam.indices.modules.insert(module_name, module);
                     }
@@ -632,36 +627,33 @@ impl<'a> LoadState<'a> {
                 code_dir,
                 op_dir,
                 meta_predicates,
-            );
+            ).unwrap();
         }
     }
 
-    pub(crate)
+    pub(crate) fn add_module(&mut self, module_decl: ModuleDecl, listing_src: ListingSource) {
-    fn add_module(&mut self, module_decl: ModuleDecl, listing_src: ListingSource) {
         let module_name = module_decl.name.clone();
 
-        let mut module =
+        let mut module = match self.wam.indices.modules.remove(&module_name) {
-            match self.wam.indices.modules.remove(&module_name) {
+            Some(mut module) => {
-                Some(mut module) => {
+                let old_module_decl = mem::replace(&mut module.module_decl, module_decl);
-                    let old_module_decl = mem::replace(&mut module.module_decl, module_decl);
 
-                    self.retraction_info.push_record(
+                self.retraction_info
-                        RetractionRecord::ReplacedModule(
+                    .push_record(RetractionRecord::ReplacedModule(
-                            old_module_decl, listing_src.clone(),
+                        old_module_decl,
-                        ),
+                        listing_src.clone(),
-                    );
+                    ));
 
-                    module.listing_src = listing_src;
+                module.listing_src = listing_src;
-                    module
+                module
-                }
+            }
-                None => {
+            None => {
-                    self.retraction_info.push_record(
+                self.retraction_info
-                        RetractionRecord::AddedModule(module_name.clone()),
+                    .push_record(RetractionRecord::AddedModule(module_name.clone()));
-                    );
 
-                    Module::new(module_decl, listing_src)
+                Module::new(module_decl, listing_src)
-                }
+            }
-            };
+        };
 
         self.import_builtins_in_module(
             &mut module.code_dir,
@@ -689,8 +681,7 @@ impl<'a> LoadState<'a> {
         self.wam.indices.modules.insert(module_name, module);
     }
 
-    pub(super)
+    pub(super) fn import_module(&mut self, module_name: ClauseName) -> Result<(), SessionError> {
-    fn import_module(&mut self, module_name: ClauseName) -> Result<(), SessionError> {
         if let Some(module) = self.wam.indices.modules.remove(&module_name) {
             match &self.compilation_target {
                 CompilationTarget::User => {
@@ -701,7 +692,7 @@ impl<'a> LoadState<'a> {
                         &mut self.wam.indices.code_dir,
                         &mut self.wam.indices.op_dir,
                         &mut self.wam.indices.meta_predicates,
-                    );
+                    )?;
                 }
                 CompilationTarget::Module(ref defining_module_name) => {
                     match self.wam.indices.modules.get_mut(defining_module_name) {
@@ -715,7 +706,7 @@ impl<'a> LoadState<'a> {
                                 &mut target_module.meta_predicates,
                                 &mut self.wam.indices.op_dir,
                                 &mut self.module_op_exports,
-                            );
+                            )?;
                         }
                         None => {
                             // we find ourselves here because we're trying to import
@@ -730,7 +721,9 @@ impl<'a> LoadState<'a> {
             self.wam.indices.modules.insert(module_name, module);
             Ok(())
         } else {
-            Err(SessionError::ExistenceError(ExistenceError::Module(module_name)))
+            Err(SessionError::ExistenceError(ExistenceError::Module(
+                module_name,
+            )))
         }
     }
 
@@ -749,7 +742,7 @@ impl<'a> LoadState<'a> {
                         &exports,
                         &mut self.wam.indices.code_dir,
                         &mut self.wam.indices.op_dir,
-                    );
+                    )?;
                 }
                 CompilationTarget::Module(ref defining_module_name) => {
                     match self.wam.indices.modules.get_mut(defining_module_name) {
@@ -763,7 +756,7 @@ impl<'a> LoadState<'a> {
                                 &mut target_module.op_dir,
                                 &mut self.wam.indices.op_dir,
                                 &mut self.module_op_exports,
-                            );
+                            )?;
                         }
                         None => {
                             // we find ourselves here because we're trying to import
@@ -778,41 +771,41 @@ impl<'a> LoadState<'a> {
             self.wam.indices.modules.insert(module_name, module);
             Ok(())
         } else {
-            Err(SessionError::ExistenceError(ExistenceError::Module(module_name)))
+            Err(SessionError::ExistenceError(ExistenceError::Module(
+                module_name,
+            )))
         }
     }
 
-    pub(crate)
+    pub(crate) fn use_module(&mut self, module_src: ModuleSource) -> Result<(), SessionError> {
-    fn use_module(&mut self, module_src: ModuleSource) -> Result<(), SessionError> {
+        let (stream, listing_src) = match module_src {
-        let (stream, listing_src) =
+            ModuleSource::File(filename) => {
-            match module_src {
+                let mut path_buf = PathBuf::from(filename.as_str());
-                ModuleSource::File(filename) => {
+                path_buf.set_extension("pl");
-                    let mut path_buf = PathBuf::from(filename.as_str());
+                let file = File::open(&path_buf)?;
-                    path_buf.set_extension("pl");
-                    let file = File::open(&path_buf)?;
 
-                    (Stream::from_file_as_input(filename.clone(), file),
+                (
-                     ListingSource::File(filename, path_buf))
+                    Stream::from_file_as_input(filename.clone(), file),
-                }
+                    ListingSource::File(filename, path_buf),
-                ModuleSource::Library(library) => {
+                )
-                    match LIBRARIES.borrow().get(library.as_str()) {
+            }
-                        Some(code) => {
+            ModuleSource::Library(library) => match LIBRARIES.borrow().get(library.as_str()) {
-                            if let Some(ref module) = self.wam.indices.modules.get(&library) {
+                Some(code) => {
-                                if let ListingSource::DynamicallyGenerated = &module.listing_src {
+                    if let Some(ref module) = self.wam.indices.modules.get(&library) {
-                                    (Stream::from(*code), ListingSource::User)
+                        if let ListingSource::DynamicallyGenerated = &module.listing_src {
-                                } else {
+                            (Stream::from(*code), ListingSource::User)
-                                    return self.import_module(library);
+                        } else {
-                                }
-                            } else {
-                                (Stream::from(*code), ListingSource::User)
-                            }
-                        }
-                        None => {
                             return self.import_module(library);
                         }
+                    } else {
+                        (Stream::from(*code), ListingSource::User)
                     }
                 }
-            };
+                None => {
+                    return self.import_module(library);
+                }
+            },
+        };
 
         let compilation_target = {
             let stream = &mut parsing_stream(stream)?;
@@ -833,43 +826,39 @@ impl<'a> LoadState<'a> {
                 // nothing to do.
                 Ok(())
             }
-            CompilationTarget::Module(module_name) => {
+            CompilationTarget::Module(module_name) => self.import_module(module_name),
-                self.import_module(module_name)
-            }
         }
     }
 
-    pub(crate)
+    pub(crate) fn use_qualified_module(
-    fn use_qualified_module(
         &mut self,
         module_src: ModuleSource,
         exports: IndexSet<ModuleExport>,
     ) -> Result<(), SessionError> {
-        let (stream, listing_src) =
+        let (stream, listing_src) = match module_src {
-            match module_src {
+            ModuleSource::File(filename) => {
-                ModuleSource::File(filename) => {
+                let mut path_buf = PathBuf::from(filename.as_str());
-                    let mut path_buf = PathBuf::from(filename.as_str());
+                path_buf.set_extension("pl");
-                    path_buf.set_extension("pl");
+                let file = File::open(&path_buf)?;
-                    let file = File::open(&path_buf)?;
 
-                    (Stream::from_file_as_input(filename.clone(), file),
+                (
-                     ListingSource::File(filename, path_buf))
+                    Stream::from_file_as_input(filename.clone(), file),
-                }
+                    ListingSource::File(filename, path_buf),
-                ModuleSource::Library(library) => {
+                )
-                    match LIBRARIES.borrow().get(library.as_str()) {
+            }
-                        Some(code) => {
+            ModuleSource::Library(library) => match LIBRARIES.borrow().get(library.as_str()) {
-                            if self.wam.indices.modules.contains_key(&library) {
+                Some(code) => {
-                                return self.import_qualified_module(library, exports);
+                    if self.wam.indices.modules.contains_key(&library) {
-                            } else {
+                        return self.import_qualified_module(library, exports);
-                                (Stream::from(*code), ListingSource::User)
+                    } else {
-                            }
+                        (Stream::from(*code), ListingSource::User)
-                        }
-                        None => {
-                            return self.import_qualified_module(library, exports);
-                        }
                     }
                 }
-            };
+                None => {
+                    return self.import_qualified_module(library, exports);
+                }
+            },
+        };
 
         let compilation_target = {
             let stream = &mut parsing_stream(stream)?;
@@ -897,12 +886,9 @@ impl<'a> LoadState<'a> {
     }
 
     #[inline]
-    pub(super)
+    pub(super) fn composite_op_dir(&self) -> CompositeOpDir {
-    fn composite_op_dir(&self) -> CompositeOpDir {
         match &self.compilation_target {
-            CompilationTarget::User => {
+            CompilationTarget::User => CompositeOpDir::new(&self.wam.indices.op_dir, None),
-                CompositeOpDir::new(&self.wam.indices.op_dir, None)
-            }
             CompilationTarget::Module(ref module_name) => {
                 match self.wam.indices.modules.get(module_name) {
                     Some(ref module) => {

src/machine/machine_errors.rs

@@ -1,6 +1,8 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
+use prolog_parser::{clause_name, temp_v};
 
 use crate::forms::{ModuleSource, Number}; //, PredicateKey};
+use crate::machine::PredicateKey;
 use crate::machine::heap::*;
 use crate::machine::machine_indices::*;
 use crate::machine::machine_state::*;
@@ -23,74 +25,59 @@ pub(crate) struct MachineError {
     from: ErrorProvenance,
 }
 
-pub(crate)
+pub(crate) trait TypeError {
-trait TypeError {
     fn type_error(self, h: usize, valid_type: ValidType) -> MachineError;
 }
 
 impl TypeError for Addr {
     fn type_error(self, _: usize, valid_type: ValidType) -> MachineError {
-        let stub = functor!(
+        let stub = functor!("type_error", [atom(valid_type.as_str()), addr(self)]);
-            "type_error",
-            [atom(valid_type.as_str()), addr(self)]
-        );
 
         MachineError {
             stub,
             location: None,
-            from: ErrorProvenance::Received
+            from: ErrorProvenance::Received,
         }
     }
 }
 
 impl TypeError for HeapCellValue {
     fn type_error(self, _: usize, valid_type: ValidType) -> MachineError {
-        let stub = functor!(
+        let stub = functor!("type_error", [atom(valid_type.as_str()), value(self)]);
-            "type_error",
-            [atom(valid_type.as_str()), value(self)]
-        );
 
         MachineError {
             stub,
             location: None,
-            from: ErrorProvenance::Received
+            from: ErrorProvenance::Received,
         }
     }
 }
 
 impl TypeError for MachineStub {
     fn type_error(self, h: usize, valid_type: ValidType) -> MachineError {
-        let stub = functor!(
+        let stub = functor!("type_error", [atom(valid_type.as_str()), aux(h, 0)], [self]);
-            "type_error",
-            [atom(valid_type.as_str()), aux(h, 0)],
-            [self]
-        );
 
         MachineError {
             stub,
             location: None,
-            from: ErrorProvenance::Constructed
+            from: ErrorProvenance::Constructed,
         }
     }
 }
 
 impl TypeError for Number {
     fn type_error(self, _h: usize, valid_type: ValidType) -> MachineError {
-        let stub = functor!(
+        let stub = functor!("type_error", [atom(valid_type.as_str()), number(self)]);
-            "type_error",
-            [atom(valid_type.as_str()), number(self)]
-        );
 
         MachineError {
             stub,
             location: None,
-            from: ErrorProvenance::Received
+            from: ErrorProvenance::Received,
         }
     }
 }
 
-pub(crate)
+pub(crate) trait PermissionError {
-trait PermissionError {
     fn permission_error(self, h: usize, index_str: &'static str, perm: Permission) -> MachineError;
 }
 
@@ -104,7 +91,7 @@ impl PermissionError for Addr {
         MachineError {
             stub,
             location: None,
-            from: ErrorProvenance::Received
+            from: ErrorProvenance::Received,
         }
     }
 }
@@ -120,22 +107,18 @@ impl PermissionError for MachineStub {
         MachineError {
             stub,
             location: None,
-            from: ErrorProvenance::Constructed
+            from: ErrorProvenance::Constructed,
         }
     }
 }
 
-pub(super)
+pub(super) trait DomainError {
-trait DomainError {
     fn domain_error(self, error: DomainErrorType) -> MachineError;
 }
 
 impl DomainError for Addr {
     fn domain_error(self, error: DomainErrorType) -> MachineError {
-        let stub = functor!(
+        let stub = functor!("domain_error", [atom(error.as_str()), addr(self)]);
-            "domain_error",
-            [atom(error.as_str()), addr(self)]
-        );
 
         MachineError {
             stub,
@@ -147,10 +130,7 @@ impl DomainError for Addr {
 
 impl DomainError for Number {
     fn domain_error(self, error: DomainErrorType) -> MachineError {
-        let stub = functor!(
+        let stub = functor!("domain_error", [atom(error.as_str()), number(self)]);
-            "domain_error",
-            [atom(error.as_str()), number(self)]
-        );
 
         MachineError {
             stub,
@@ -161,8 +141,7 @@ impl DomainError for Number {
 }
 
 impl MachineError {
-    pub(super)
+    pub(super) fn functor_stub(name: ClauseName, arity: usize) -> MachineStub {
-    fn functor_stub(name: ClauseName, arity: usize) -> MachineStub {
         functor!(
             "/",
             SharedOpDesc::new(400, YFX),
@@ -171,8 +150,7 @@ impl MachineError {
     }
 
     #[inline]
-    pub(super)
+    pub(super) fn interrupt_error() -> Self {
-    fn interrupt_error() -> Self {
         let stub = functor!("$interrupt_thrown");
 
         MachineError {
@@ -182,8 +160,7 @@ impl MachineError {
         }
     }
 
-    pub(super)
+    pub(super) fn evaluation_error(eval_error: EvalError) -> Self {
-    fn evaluation_error(eval_error: EvalError) -> Self {
         let stub = functor!("evaluation_error", [atom(eval_error.as_str())]);
 
         MachineError {
@@ -193,13 +170,11 @@ impl MachineError {
         }
     }
 
-    pub(super)
+    pub(super) fn type_error<T: TypeError>(h: usize, valid_type: ValidType, culprit: T) -> Self {
-    fn type_error<T: TypeError>(h: usize, valid_type: ValidType, culprit: T) -> Self {
         culprit.type_error(h, valid_type)
     }
 
-    pub(super)
+    pub(super) fn module_resolution_error(
-    fn module_resolution_error(
         h: usize,
         mod_name: ClauseName,
         name: ClauseName,
@@ -218,11 +193,7 @@ impl MachineError {
             [res_stub]
         );
 
-        let stub = functor!(
+        let stub = functor!("evaluation_error", [aux(h, 0)], [ind_stub]);
-            "evaluation_error",
-            [aux(h, 0)],
-            [ind_stub]
-        );
 
         MachineError {
             stub,
@@ -231,14 +202,10 @@ impl MachineError {
         }
     }
 
-    pub(super)
+    pub(super) fn existence_error(h: usize, err: ExistenceError) -> Self {
-    fn existence_error(h: usize, err: ExistenceError) -> Self {
         match err {
             ExistenceError::Module(name) => {
-                let stub = functor!(
+                let stub = functor!("existence_error", [atom("source_sink"), clause_name(name)]);
-                    "existence_error",
-                    [atom("source_sink"), clause_name(name)]
-                );
 
                 MachineError {
                     stub,
@@ -253,11 +220,7 @@ impl MachineError {
                     [clause_name(name), integer(arity)]
                 );
 
-                let stub = functor!(
+                let stub = functor!("existence_error", [atom("procedure"), aux(h, 0)], [culprit]);
-                    "existence_error",
-                    [atom("procedure"), aux(h, 0)],
-                    [culprit]
-                );
 
                 MachineError {
                     stub,
@@ -281,10 +244,7 @@ impl MachineError {
                 }
             }
             ExistenceError::SourceSink(culprit) => {
-                let stub = functor!(
+                let stub = functor!("existence_error", [atom("source_sink"), addr(culprit)]);
-                    "existence_error",
-                    [atom("source_sink"), addr(culprit)]
-                );
 
                 MachineError {
                     stub,
@@ -293,10 +253,7 @@ impl MachineError {
                 }
             }
             ExistenceError::Stream(culprit) => {
-                let stub = functor!(
+                let stub = functor!("existence_error", [atom("stream"), addr(culprit)]);
-                    "existence_error",
-                    [atom("stream"), addr(culprit)]
-                );
 
                 MachineError {
                     stub,
@@ -307,25 +264,18 @@ impl MachineError {
         }
     }
 
-    pub(super)
+    pub(super) fn permission_error<T: PermissionError>(
-    fn permission_error<T: PermissionError>(
         h: usize,
         err: Permission,
         index_str: &'static str,
         culprit: T,
     ) -> Self {
-        culprit.permission_error(
+        culprit.permission_error(h, index_str, err)
-            h,
-            index_str,
-            err,
-        )
     }
 
     fn arithmetic_error(h: usize, err: ArithmeticError) -> Self {
         match err {
-            ArithmeticError::UninstantiatedVar => {
+            ArithmeticError::UninstantiatedVar => Self::instantiation_error(),
-                Self::instantiation_error()
-            }
             ArithmeticError::NonEvaluableFunctor(name, arity) => {
                 let culprit = functor!(
                     "/",
@@ -339,13 +289,11 @@ impl MachineError {
     }
 
     #[inline]
-    pub(super)
+    pub(super) fn domain_error<T: DomainError>(error: DomainErrorType, culprit: T) -> Self {
-    fn domain_error<T: DomainError>(error: DomainErrorType, culprit: T) -> Self {
         culprit.domain_error(error)
     }
 
-    pub(super)
+    pub(super) fn instantiation_error() -> Self {
-    fn instantiation_error() -> Self {
         let stub = functor!("instantiation_error");
 
         MachineError {
@@ -355,8 +303,7 @@ impl MachineError {
         }
     }
 
-    pub(super)
+    pub(super) fn session_error(h: usize, err: SessionError) -> Self {
-    fn session_error(h: usize, err: SessionError) -> Self {
         match err {
             // SessionError::CannotOverwriteBuiltIn(pred_str) |
             /*
@@ -369,13 +316,10 @@ impl MachineError {
                 )
             }
             */
-            SessionError::ExistenceError(err) => {
+            SessionError::ExistenceError(err) => Self::existence_error(h, err),
-                Self::existence_error(h, err)
-            }
             // SessionError::InvalidFileName(filename) => {
             //     Self::existence_error(h, ExistenceError::Module(filename))
             // }
-            /*
             SessionError::ModuleDoesNotContainExport(..) => {
                 Self::permission_error(
                     h,
@@ -384,47 +328,32 @@ impl MachineError {
                     functor!("module_does_not_contain_claimed_export"),
                 )
             }
-            */
+            SessionError::ModuleCannotImportSelf(module_name) => Self::permission_error(
-            SessionError::ModuleCannotImportSelf(module_name) => {
+                h,
-                Self::permission_error(
+                Permission::Modify,
-                    h,
+                "module",
-                    Permission::Modify,
+                functor!("module_cannot_import_self", [clause_name(module_name)]),
-                    "module",
+            ),
-                    functor!("module_cannot_import_self", [clause_name(module_name)]),
+            SessionError::NamelessEntry => Self::permission_error(
-                )
+                h,
-            }
+                Permission::Create,
-            SessionError::NamelessEntry => {
+                "static_procedure",
-                Self::permission_error(
+                functor!("nameless_procedure"),
-                    h,
+            ),
-                    Permission::Create,
-                    "static_procedure",
-                    functor!("nameless_procedure")
-                )
-            }
             SessionError::OpIsInfixAndPostFix(op) => {
-                Self::permission_error(
+                Self::permission_error(h, Permission::Create, "operator", functor!(clause_name(op)))
-                    h,
-                    Permission::Create,
-                    "operator",
-                    functor!(clause_name(op)),
-                )
-            }
-            SessionError::CompilationError(err) => {
-                Self::syntax_error(h, err)
-            }
-            SessionError::QueryCannotBeDefinedAsFact => {
-                Self::permission_error(
-                    h,
-                    Permission::Create,
-                    "static_procedure",
-                    functor!("query_cannot_be_defined_as_fact")
-                )
             }
+            SessionError::CompilationError(err) => Self::syntax_error(h, err),
+            SessionError::QueryCannotBeDefinedAsFact => Self::permission_error(
+                h,
+                Permission::Create,
+                "static_procedure",
+                functor!("query_cannot_be_defined_as_fact"),
+            ),
         }
     }
 
-    pub(super)
+    pub(super) fn syntax_error<E: Into<CompilationError>>(h: usize, err: E) -> Self {
-    fn syntax_error<E: Into<CompilationError>>(h: usize, err: E) -> Self {
         let err = err.into();
 
         if let CompilationError::Arithmetic(err) = err {
@@ -434,11 +363,7 @@ impl MachineError {
         let location = err.line_and_col_num();
         let stub = err.as_functor(h);
 
-        let stub = functor!(
+        let stub = functor!("syntax_error", [aux(h, 0)], [stub]);
-            "syntax_error",
-            [aux(h, 0)],
-            [stub]
-        );
 
         MachineError {
             stub,
@@ -447,8 +372,7 @@ impl MachineError {
         }
     }
 
-    pub(super)
+    pub(super) fn representation_error(flag: RepFlag) -> Self {
-    fn representation_error(flag: RepFlag) -> Self {
         let stub = functor!("representation_error", [atom(flag.as_str())]);
 
         MachineError {
@@ -515,63 +439,46 @@ impl From<ParserError> for CompilationError {
 impl CompilationError {
     pub fn line_and_col_num(&self) -> Option<(usize, usize)> {
         match self {
-            &CompilationError::ParserError(ref err) =>
+            &CompilationError::ParserError(ref err) => err.line_and_col_num(),
-                err.line_and_col_num(),
+            _ => None,
-            _ =>
-                None
         }
     }
 
     pub fn as_functor(&self, _h: usize) -> MachineStub {
         match self {
-            &CompilationError::Arithmetic(..) =>
+            &CompilationError::Arithmetic(..) => functor!("arithmetic_error"),
-                functor!("arithmetic_error"),
             // &CompilationError::BadPendingByte =>
             //     functor!("bad_pending_byte"),
-            &CompilationError::CannotParseCyclicTerm =>
+            &CompilationError::CannotParseCyclicTerm => functor!("cannot_parse_cyclic_term"),
-                functor!("cannot_parse_cyclic_term"),
             // &CompilationError::ExpandedTermsListNotAList =>
             //     functor!("expanded_terms_list_is_not_a_list"),
-            &CompilationError::ExpectedRel =>
+            &CompilationError::ExpectedRel => functor!("expected_relation"),
-                functor!("expected_relation"),
             // &CompilationError::ExpectedTopLevelTerm =>
             //     functor!("expected_atom_or_cons_or_clause"),
-            &CompilationError::InadmissibleFact =>
+            &CompilationError::InadmissibleFact => functor!("inadmissible_fact"),
-                functor!("inadmissible_fact"),
+            &CompilationError::InadmissibleQueryTerm => functor!("inadmissible_query_term"),
-            &CompilationError::InadmissibleQueryTerm =>
+            &CompilationError::InconsistentEntry => functor!("inconsistent_entry"),
-                functor!("inadmissible_query_term"),
-            &CompilationError::InconsistentEntry =>
-                functor!("inconsistent_entry"),
             // &CompilationError::InvalidDoubleQuotesDecl =>
             //     functor!("invalid_double_quotes_declaration"),
             // &CompilationError::InvalidHook =>
             //     functor!("invalid_hook"),
-            &CompilationError::InvalidMetaPredicateDecl =>
+            &CompilationError::InvalidMetaPredicateDecl => functor!("invalid_meta_predicate_decl"),
-                functor!("invalid_meta_predicate_decl"),
+            &CompilationError::InvalidModuleDecl => functor!("invalid_module_declaration"),
-            &CompilationError::InvalidModuleDecl =>
+            &CompilationError::InvalidModuleExport => functor!("invalid_module_export"),
-                functor!("invalid_module_declaration"),
+            &CompilationError::InvalidModuleResolution(ref module_name) => {
-            &CompilationError::InvalidModuleExport =>
+                functor!("no_such_module", [clause_name(module_name.clone())])
-                functor!("invalid_module_export"),
+            }
-            &CompilationError::InvalidModuleResolution(ref module_name) =>
+            &CompilationError::InvalidRuleHead => functor!("invalid_head_of_rule"),
-                functor!(
+            &CompilationError::InvalidUseModuleDecl => functor!("invalid_use_module_declaration"),
-                    "no_such_module",
+            &CompilationError::ParserError(ref err) => functor!(err.as_str()),
-                    [clause_name(module_name.clone())]
+            &CompilationError::UnreadableTerm => functor!("unreadable_term"),
-                ),
-            &CompilationError::InvalidRuleHead =>
-                functor!("invalid_head_of_rule"),
-            &CompilationError::InvalidUseModuleDecl =>
-                functor!("invalid_use_module_declaration"),
-            &CompilationError::ParserError(ref err) =>
-                functor!(err.as_str()),
-            &CompilationError::UnreadableTerm =>
-                functor!("unreadable_term"),
         }
     }
 }
 
 #[derive(Debug, Clone, Copy)]
 pub enum Permission {
-    // Access,
+    Access,
     Create,
     InputStream,
     Modify,
@@ -584,7 +491,7 @@ impl Permission {
     #[inline]
     pub fn as_str(self) -> &'static str {
         match self {
-            // Permission::Access => "access",
+            Permission::Access => "access",
             Permission::Create => "create",
             Permission::InputStream => "input",
             Permission::Modify => "modify",
@@ -715,16 +622,15 @@ impl EvalError {
 pub(super) enum CycleSearchResult {
     EmptyList,
     NotList,
-    PartialList(usize, Ref),           // the list length (up to max), and an offset into the heap.
+    PartialList(usize, Ref), // the list length (up to max), and an offset into the heap.
-    ProperList(usize),                 // the list length.
+    ProperList(usize),       // the list length.
     PStrLocation(usize, usize, usize), // the list length (up to max), the heap offset, byte offset into the string.
     UntouchedList(usize),              // the address of an uniterated Addr::Lis(address).
 }
 
 impl MachineState {
     // see 8.4.3 of Draft Technical Corrigendum 2.
-    pub(super)
+    pub(super) fn check_sort_errors(&self) -> CallResult {
-    fn check_sort_errors(&self) -> CallResult {
         let stub = MachineError::functor_stub(clause_name!("sort"), 2);
         let list = self.store(self.deref(self[temp_v!(1)].clone()));
         let sorted = self.store(self.deref(self[temp_v!(2)].clone()));
@@ -734,7 +640,9 @@ impl MachineState {
                 return Err(self.error_form(MachineError::instantiation_error(), stub))
             }
             CycleSearchResult::NotList => {
-                return Err(self.error_form(MachineError::type_error(0, ValidType::List, list), stub))
+                return Err(
+                    self.error_form(MachineError::type_error(0, ValidType::List, list), stub)
+                )
             }
             _ => {}
         };
@@ -766,7 +674,8 @@ impl MachineState {
                                 new_l = l;
                             }
                             HeapCellValue::NamedStr(2, ref name, Some(_))
-                                if name.as_str() == "-" => {
+                                if name.as_str() == "-" =>
+                            {
                                 break;
                             }
                             HeapCellValue::Addr(Addr::HeapCell(_)) => {
@@ -793,11 +702,10 @@ impl MachineState {
     }
 
     // see 8.4.4 of Draft Technical Corrigendum 2.
-    pub(super)
+    pub(super) fn check_keysort_errors(&self) -> CallResult {
-    fn check_keysort_errors(&self) -> CallResult {
         let stub = MachineError::functor_stub(clause_name!("keysort"), 2);
 
-        let pairs  = self.store(self.deref(self[temp_v!(1)].clone()));
+        let pairs = self.store(self.deref(self[temp_v!(1)].clone()));
         let sorted = self.store(self.deref(self[temp_v!(2)].clone()));
 
         match self.detect_cycles(pairs.clone()) {
@@ -814,8 +722,7 @@ impl MachineState {
     }
 
     #[inline]
-    pub(crate)
+    pub(crate) fn type_error<T: TypeError>(
-    fn type_error<T: TypeError>(
         &self,
         valid_type: ValidType,
         culprit: T,
@@ -823,33 +730,25 @@ impl MachineState {
         arity: usize,
     ) -> MachineStub {
         let stub = MachineError::functor_stub(caller, arity);
-        let err = MachineError::type_error(
+        let err = MachineError::type_error(self.heap.h(), valid_type, culprit);
-            self.heap.h(),
-            valid_type,
-            culprit,
-        );
 
         return self.error_form(err, stub);
     }
 
     #[inline]
-    pub(crate)
+    pub(crate) fn representation_error(
-    fn representation_error(
         &self,
         rep_flag: RepFlag,
         caller: ClauseName,
         arity: usize,
     ) -> MachineStub {
         let stub = MachineError::functor_stub(caller, arity);
-        let err = MachineError::representation_error(
+        let err = MachineError::representation_error(rep_flag);
-            rep_flag,
-        );
 
         return self.error_form(err, stub);
     }
 
-    pub(super)
+    pub(super) fn error_form(&self, err: MachineError, src: MachineStub) -> MachineStub {
-    fn error_form(&self, err: MachineError, src: MachineStub) -> MachineStub {
         let location = err.location;
         let err_len = err.len();
 
@@ -874,8 +773,7 @@ impl MachineState {
         stub
     }
 
-    pub(super)
+    pub(super) fn throw_exception(&mut self, err: MachineStub) {
-    fn throw_exception(&mut self, err: MachineStub) {
         let h = self.heap.h();
 
         self.ball.boundary = 0;
@@ -906,7 +804,7 @@ pub enum SessionError {
     // CannotOverwriteImport(ClauseName),
     ExistenceError(ExistenceError),
     // InvalidFileName(ClauseName),
-    // ModuleDoesNotContainExport(ClauseName, PredicateKey),
+    ModuleDoesNotContainExport(ClauseName, PredicateKey),
     ModuleCannotImportSelf(ClauseName),
     NamelessEntry,
     OpIsInfixAndPostFix(ClauseName),

src/machine/machine_indices.rs

@@ -1,22 +1,23 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
+use prolog_parser::clause_name;
 
 use crate::clause_types::*;
 use crate::fixtures::*;
 use crate::forms::*;
-use crate::machine::CompilationTarget;
+use crate::instructions::*;
 use crate::machine::code_repo::CodeRepo;
-use crate::machine::Ball;
 use crate::machine::heap::*;
 use crate::machine::machine_state::*;
 use crate::machine::partial_string::*;
 use crate::machine::raw_block::RawBlockTraits;
 use crate::machine::streams::Stream;
 use crate::machine::term_stream::LoadStatePayload;
-use crate::instructions::*;
+use crate::machine::Ball;
-use crate::ordered_float::OrderedFloat;
+use crate::machine::CompilationTarget;
 use crate::rug::{Integer, Rational};
+use ordered_float::OrderedFloat;
 
-use crate::indexmap::IndexMap;
+use indexmap::IndexMap;
 
 use std::cell::Cell;
 use std::cmp::Ordering;
@@ -96,20 +97,14 @@ impl Ord for Ref {
     fn cmp(&self, other: &Ref) -> Ordering {
         match (self, other) {
             (Ref::AttrVar(h1), Ref::AttrVar(h2))
-          | (Ref::HeapCell(h1), Ref::HeapCell(h2))
+            | (Ref::HeapCell(h1), Ref::HeapCell(h2))
-          | (Ref::HeapCell(h1), Ref::AttrVar(h2))
+            | (Ref::HeapCell(h1), Ref::AttrVar(h2))
-          | (Ref::AttrVar(h1), Ref::HeapCell(h2)) => {
+            | (Ref::AttrVar(h1), Ref::HeapCell(h2)) => h1.cmp(&h2),
-                h1.cmp(&h2)
-            }
             (Ref::StackCell(fr1, sc1), Ref::StackCell(fr2, sc2)) => {
                 fr1.cmp(&fr2).then_with(|| sc1.cmp(&sc2))
             }
-            (Ref::StackCell(..), _) => {
+            (Ref::StackCell(..), _) => Ordering::Greater,
-                Ordering::Greater
+            (_, Ref::StackCell(..)) => Ordering::Less,
-            }
-            (_, Ref::StackCell(..)) => {
-                Ordering::Less
-            }
         }
     }
 }
@@ -124,35 +119,23 @@ impl PartialEq<Ref> for Addr {
 impl PartialOrd<Ref> for Addr {
     fn partial_cmp(&self, r: &Ref) -> Option<Ordering> {
         match self {
-            &Addr::StackCell(fr, sc) => {
+            &Addr::StackCell(fr, sc) => match *r {
-                match *r {
+                Ref::AttrVar(_) | Ref::HeapCell(_) => Some(Ordering::Greater),
-                    Ref::AttrVar(_) | Ref::HeapCell(_) => {
+                Ref::StackCell(fr1, sc1) => {
+                    if fr1 < fr || (fr1 == fr && sc1 < sc) {
                         Some(Ordering::Greater)
-                    }
+                    } else if fr1 == fr && sc1 == sc {
-                    Ref::StackCell(fr1, sc1) => {
+                        Some(Ordering::Equal)
-                        if fr1 < fr || (fr1 == fr && sc1 < sc) {
+                    } else {
-                            Some(Ordering::Greater)
-                        } else if fr1 == fr && sc1 == sc {
-                            Some(Ordering::Equal)
-                        } else {
-                            Some(Ordering::Less)
-                        }
-                    }
-                }
-            }
-            &Addr::HeapCell(h) | &Addr::AttrVar(h) => {
-                match r {
-                    Ref::StackCell(..) => {
                         Some(Ordering::Less)
                     }
-                    Ref::AttrVar(h1) | Ref::HeapCell(h1) => {
-                        h.partial_cmp(h1)
-                    }
                 }
-            }
+            },
-            _ => {
+            &Addr::HeapCell(h) | &Addr::AttrVar(h) => match r {
-                None
+                Ref::StackCell(..) => Some(Ordering::Less),
-            }
+                Ref::AttrVar(h1) | Ref::HeapCell(h1) => h.partial_cmp(h1),
+            },
+            _ => None,
         }
     }
 }
@@ -161,26 +144,21 @@ impl Addr {
     #[inline]
     pub fn is_heap_bound(&self) -> bool {
         match self {
-            Addr::Char(_) | Addr::EmptyList |
+            Addr::Char(_)
-            Addr::CutPoint(_) | Addr::Usize(_) | Addr::Fixnum(_) |
+            | Addr::EmptyList
-            Addr::Float(_) => {
+            | Addr::CutPoint(_)
-                false
+            | Addr::Usize(_)
-            }
+            | Addr::Fixnum(_)
-            _ => {
+            | Addr::Float(_) => false,
-                true
+            _ => true,
-            }
         }
     }
 
     #[inline]
     pub fn is_ref(&self) -> bool {
         match self {
-            Addr::HeapCell(_) | Addr::StackCell(_, _) | Addr::AttrVar(_) => {
+            Addr::HeapCell(_) | Addr::StackCell(_, _) | Addr::AttrVar(_) => true,
-                true
+            _ => false,
-            }
-            _ => {
-                false
-            }
         }
     }
 
@@ -194,92 +172,54 @@ impl Addr {
         }
     }
 
-    pub(super)
+    pub(super) fn order_category(&self, heap: &Heap) -> Option<TermOrderCategory> {
-    fn order_category(&self, heap: &Heap) -> Option<TermOrderCategory> {
         match Number::try_from((*self, heap)) {
             Ok(Number::Integer(_)) | Ok(Number::Fixnum(_)) | Ok(Number::Rational(_)) => {
                 Some(TermOrderCategory::Integer)
             }
-            Ok(Number::Float(_)) => {
+            Ok(Number::Float(_)) => Some(TermOrderCategory::FloatingPoint),
-                Some(TermOrderCategory::FloatingPoint)
+            _ => match self {
-            }
+                Addr::HeapCell(_) | Addr::AttrVar(_) | Addr::StackCell(..) => {
-            _ => {
+                    Some(TermOrderCategory::Variable)
-                match self {
-                    Addr::HeapCell(_) | Addr::AttrVar(_) | Addr::StackCell(..) => {
-                        Some(TermOrderCategory::Variable)
-                    }
-                    Addr::Float(_) => {
-                        Some(TermOrderCategory::FloatingPoint)
-                    }
-                    &Addr::Con(h) => {
-                        match &heap[h] {
-                            HeapCellValue::Atom(..) => {
-                                Some(TermOrderCategory::Atom)
-                            }
-                            HeapCellValue::DBRef(_) => {
-                                None
-                            }
-                            _ => {
-                                unreachable!()
-                            }
-                        }
-                    }
-                    Addr::Char(_) | Addr::EmptyList => {
-                        Some(TermOrderCategory::Atom)
-                    }
-                    Addr::Fixnum(_) | Addr::Usize(_) => {
-                        Some(TermOrderCategory::Integer)
-                    }
-                    Addr::Lis(_) | Addr::PStrLocation(..) | Addr::Str(_) => {
-                        Some(TermOrderCategory::Compound)
-                    }
-                    Addr::CutPoint(_) | Addr::LoadStatePayload(_) | Addr::Stream(_) | Addr::TcpListener(_) => {
-                        None
-                    }
                 }
-            }
+                Addr::Float(_) => Some(TermOrderCategory::FloatingPoint),
+                &Addr::Con(h) => match &heap[h] {
+                    HeapCellValue::Atom(..) => Some(TermOrderCategory::Atom),
+                    HeapCellValue::DBRef(_) => None,
+                    _ => {
+                        unreachable!()
+                    }
+                },
+                Addr::Char(_) | Addr::EmptyList => Some(TermOrderCategory::Atom),
+                Addr::Fixnum(_) | Addr::Usize(_) => Some(TermOrderCategory::Integer),
+                Addr::Lis(_) | Addr::PStrLocation(..) | Addr::Str(_) => {
+                    Some(TermOrderCategory::Compound)
+                }
+                Addr::CutPoint(_)
+                | Addr::LoadStatePayload(_)
+                | Addr::Stream(_)
+                | Addr::TcpListener(_) => None,
+            },
         }
     }
 
     pub fn as_constant_index(&self, machine_st: &MachineState) -> Option<Constant> {
         match self {
-            &Addr::Char(c) => {
+            &Addr::Char(c) => Some(Constant::Char(c)),
-                Some(Constant::Char(c))
+            &Addr::Con(h) => match &machine_st.heap[h] {
-            }
+                &HeapCellValue::Atom(ref name, _) if name.is_char() => {
-            &Addr::Con(h) => {
+                    Some(Constant::Char(name.as_str().chars().next().unwrap()))
-                match &machine_st.heap[h] {
-                    &HeapCellValue::Atom(ref name, _) if name.is_char() => {
-                        Some(Constant::Char(name.as_str().chars().next().unwrap()))
-                    }
-                    &HeapCellValue::Atom(ref name, _) => {
-                        Some(Constant::Atom(name.clone(), None))
-                    }
-                    &HeapCellValue::Integer(ref n) => {
-                        Some(Constant::Integer(n.clone()))
-                    }
-                    &HeapCellValue::Rational(ref n) => {
-                        Some(Constant::Rational(n.clone()))
-                    }
-                    _ => {
-                        None
-                    }
                 }
-            }
+                &HeapCellValue::Atom(ref name, _) => Some(Constant::Atom(name.clone(), None)),
-            &Addr::EmptyList => {
+                &HeapCellValue::Integer(ref n) => Some(Constant::Integer(n.clone())),
-                Some(Constant::EmptyList)
+                &HeapCellValue::Rational(ref n) => Some(Constant::Rational(n.clone())),
-            }
+                _ => None,
-            &Addr::Fixnum(n) => {
+            },
-                Some(Constant::Fixnum(n))
+            &Addr::EmptyList => Some(Constant::EmptyList),
-            }
+            &Addr::Fixnum(n) => Some(Constant::Fixnum(n)),
-            &Addr::Float(f) => {
+            &Addr::Float(f) => Some(Constant::Float(f)),
-                Some(Constant::Float(f))
+            &Addr::Usize(n) => Some(Constant::Usize(n)),
-            }
+            _ => None,
-            &Addr::Usize(n) => {
-                Some(Constant::Usize(n))
-            }
-            _ => {
-                None
-            }
         }
     }
 
@@ -383,61 +323,37 @@ impl HeapCellValue {
     #[inline]
     pub fn as_addr(&self, focus: usize) -> Addr {
         match self {
-            HeapCellValue::Addr(ref a) => {
+            HeapCellValue::Addr(ref a) => *a,
-                *a
+            HeapCellValue::Atom(..)
-            }
+            | HeapCellValue::DBRef(..)
-            HeapCellValue::Atom(..) | HeapCellValue::DBRef(..) | HeapCellValue::Integer(..) |
+            | HeapCellValue::Integer(..)
-            HeapCellValue::Rational(..) => {
+            | HeapCellValue::Rational(..) => Addr::Con(focus),
-                Addr::Con(focus)
+            HeapCellValue::LoadStatePayload(_) => Addr::LoadStatePayload(focus),
-            }
+            HeapCellValue::NamedStr(_, _, _) => Addr::Str(focus),
-            HeapCellValue::LoadStatePayload(_) => {
+            HeapCellValue::PartialString(..) => Addr::PStrLocation(focus, 0),
-                Addr::LoadStatePayload(focus)
+            HeapCellValue::Stream(_) => Addr::Stream(focus),
-            }
+            HeapCellValue::TcpListener(_) => Addr::TcpListener(focus),
-            HeapCellValue::NamedStr(_, _, _) => {
-                Addr::Str(focus)
-            }
-            HeapCellValue::PartialString(..) => {
-                Addr::PStrLocation(focus, 0)
-            }
-            HeapCellValue::Stream(_) => {
-                Addr::Stream(focus)
-            }
-            HeapCellValue::TcpListener(_) => {
-                Addr::TcpListener(focus)
-            }
         }
     }
 
     #[inline]
     pub fn context_free_clone(&self) -> HeapCellValue {
         match self {
-            &HeapCellValue::Addr(addr) => {
+            &HeapCellValue::Addr(addr) => HeapCellValue::Addr(addr),
-                HeapCellValue::Addr(addr)
+            &HeapCellValue::Atom(ref name, ref op) => HeapCellValue::Atom(name.clone(), op.clone()),
-            }
+            &HeapCellValue::DBRef(ref db_ref) => HeapCellValue::DBRef(db_ref.clone()),
-            &HeapCellValue::Atom(ref name, ref op) => {
+            &HeapCellValue::Integer(ref n) => HeapCellValue::Integer(n.clone()),
-                HeapCellValue::Atom(name.clone(), op.clone())
-            }
-            &HeapCellValue::DBRef(ref db_ref) => {
-                HeapCellValue::DBRef(db_ref.clone())
-            }
-            &HeapCellValue::Integer(ref n) => {
-                HeapCellValue::Integer(n.clone())
-            }
             &HeapCellValue::LoadStatePayload(_) => {
                 HeapCellValue::Atom(clause_name!("$live_term_stream"), None)
             }
             &HeapCellValue::NamedStr(arity, ref name, ref op) => {
                 HeapCellValue::NamedStr(arity, name.clone(), op.clone())
             }
-            &HeapCellValue::Rational(ref r) => {
+            &HeapCellValue::Rational(ref r) => HeapCellValue::Rational(r.clone()),
-                HeapCellValue::Rational(r.clone())
-            }
             &HeapCellValue::PartialString(ref pstr, has_tail) => {
                 HeapCellValue::PartialString(pstr.clone(), has_tail)
             }
-            &HeapCellValue::Stream(ref stream) => {
+            &HeapCellValue::Stream(ref stream) => HeapCellValue::Stream(stream.clone()),
-                HeapCellValue::Stream(stream.clone())
-            }
             &HeapCellValue::TcpListener(_) => {
                 HeapCellValue::Atom(clause_name!("$tcp_listener"), None)
             }
@@ -473,8 +389,7 @@ impl Deref for CodeIndex {
 
 impl CodeIndex {
     #[inline]
-    pub(super)
+    pub(super) fn new(ptr: IndexPtr) -> Self {
-    fn new(ptr: IndexPtr) -> Self {
         CodeIndex(Rc::new(Cell::new(ptr)))
     }
 
@@ -482,7 +397,7 @@ impl CodeIndex {
     pub fn is_undefined(&self) -> bool {
         match self.0.get() {
             IndexPtr::Undefined => true, // | &IndexPtr::DynamicUndefined => true,
-            _ => false
+            _ => false,
         }
     }
 
@@ -505,7 +420,6 @@ pub enum REPLCodePtr {
     AddDynamicPredicate,
     AddGoalExpansionClause,
     AddTermExpansionClause,
-    BuiltInProperty,
     ClauseToEvacuable,
     ConcludeLoad,
     DeclareModule,
@@ -520,11 +434,15 @@ pub enum REPLCodePtr {
     PushLoadContext,
     PushLoadStatePayload,
     UseModule,
+    BuiltInProperty,
     MetaPredicateProperty,
-    CompilePendingPredicates,
+    MultifileProperty,
-    UserAsserta,
+    DiscontiguousProperty,
-    UserAssertz,
+    DynamicProperty,
-    UserRetract,
+    AbolishClause,
+    Asserta,
+    Assertz,
+    Retract,
 }
 
 #[derive(Debug, Clone, PartialEq)]
@@ -533,7 +451,7 @@ pub enum CodePtr {
     CallN(usize, LocalCodePtr, bool),               // arity, local, last call.
     Local(LocalCodePtr),
     // DynamicTransaction(DynamicTransactionType, LocalCodePtr), // the type of transaction, the return pointer.
-    REPL(REPLCodePtr, LocalCodePtr),                          // the REPL code, the return pointer.
+    REPL(REPLCodePtr, LocalCodePtr), // the REPL code, the return pointer.
     VerifyAttrInterrupt(usize), // location of the verify attribute interrupt code in the CodeDir.
 }
 
@@ -541,10 +459,10 @@ impl CodePtr {
     pub fn local(&self) -> LocalCodePtr {
         match self {
             &CodePtr::BuiltInClause(_, ref local)
-          | &CodePtr::CallN(_, ref local, _)
+            | &CodePtr::CallN(_, ref local, _)
-          | &CodePtr::Local(ref local) => local.clone(),
+            | &CodePtr::Local(ref local) => local.clone(),
             &CodePtr::VerifyAttrInterrupt(p) => LocalCodePtr::DirEntry(p),
-            &CodePtr::REPL(_, p) => p // | &CodePtr::DynamicTransaction(_, p) => p,
+            &CodePtr::REPL(_, p) => p, // | &CodePtr::DynamicTransaction(_, p) => p,
         }
     }
 
@@ -563,12 +481,11 @@ pub enum LocalCodePtr {
     DirEntry(usize), // offset
     Halt,
     IndexingBuf(usize, usize, usize), // DirEntry offset, first internal offset, second internal offset
-    // TopLevel(usize, usize), // chunk_num, offset
+                                      // TopLevel(usize, usize), // chunk_num, offset
 }
 
 impl LocalCodePtr {
-    pub(crate)
+    pub(crate) fn assign_if_local(&mut self, cp: CodePtr) {
-    fn assign_if_local(&mut self, cp: CodePtr) {
         match cp {
             CodePtr::Local(local) => *self = local,
             _ => {}
@@ -576,8 +493,7 @@ impl LocalCodePtr {
     }
 
     #[inline]
-    pub(crate)
+    pub(crate) fn abs_loc(&self) -> usize {
-    fn abs_loc(&self) -> usize {
         match self {
             LocalCodePtr::DirEntry(ref p) => *p,
             LocalCodePtr::IndexingBuf(ref p, ..) => *p,
@@ -585,35 +501,28 @@ impl LocalCodePtr {
         }
     }
 
-    pub(crate)
+    pub(crate) fn is_reset_cont_marker(&self, code_repo: &CodeRepo, last_call: bool) -> bool {
-    fn is_reset_cont_marker(&self, code_repo: &CodeRepo, last_call: bool) -> bool {
         match code_repo.lookup_instr(last_call, &CodePtr::Local(*self)) {
-            Some(line) => {
+            Some(line) => match line.as_ref() {
-                match line.as_ref() {
+                Line::Control(ControlInstruction::CallClause(ref ct, ..)) => {
-                    Line::Control(ControlInstruction::CallClause(ref ct, ..)) => {
+                    if let ClauseType::System(SystemClauseType::ResetContinuationMarker) = *ct {
-                        if let ClauseType::System(SystemClauseType::ResetContinuationMarker) = *ct {
+                        return true;
-                            return true;
-                        }
                     }
-                    _ => {}
                 }
-            }
+                _ => {}
+            },
             None => {}
         }
 
         false
     }
 
-    pub(crate)
+    pub(crate) fn as_functor<T: RawBlockTraits>(&self, heap: &mut HeapTemplate<T>) -> Addr {
-    fn as_functor<T: RawBlockTraits>(&self, heap: &mut HeapTemplate<T>) -> Addr {
         let addr = Addr::HeapCell(heap.h());
 
         match self {
             LocalCodePtr::DirEntry(p) => {
-                heap.append(functor!(
+                heap.append(functor!("dir_entry", [integer(*p)]));
-                    "dir_entry",
-                    [integer(*p)]
-                ));
             }
             LocalCodePtr::Halt => {
                 heap.append(functor!("halt"));
@@ -655,7 +564,7 @@ impl PartialOrd<CodePtr> for CodePtr {
 impl PartialOrd<LocalCodePtr> for LocalCodePtr {
     fn partial_cmp(&self, other: &LocalCodePtr) -> Option<Ordering> {
         match (self, other) {
-	        (&LocalCodePtr::DirEntry(p1), &LocalCodePtr::DirEntry(ref p2)) |
+            (&LocalCodePtr::DirEntry(p1), &LocalCodePtr::DirEntry(ref p2)) |
             (&LocalCodePtr::TopLevel(_, p1), &LocalCodePtr::TopLevel(_, ref p2)) => {
                 p1.partial_cmp(p2)
             }
@@ -690,12 +599,9 @@ impl Add<usize> for LocalCodePtr {
     #[inline]
     fn add(self, rhs: usize) -> Self::Output {
         match self {
-            LocalCodePtr::DirEntry(p) =>
+            LocalCodePtr::DirEntry(p) => LocalCodePtr::DirEntry(p + rhs),
-                LocalCodePtr::DirEntry(p + rhs),
+            LocalCodePtr::Halt => unreachable!(),
-            LocalCodePtr::Halt =>
+            LocalCodePtr::IndexingBuf(p, o, i) => LocalCodePtr::IndexingBuf(p, o, i + rhs),
-                unreachable!(),
-            LocalCodePtr::IndexingBuf(p, o, i) =>
-                LocalCodePtr::IndexingBuf(p, o, i + rhs),
         }
     }
 }
@@ -706,12 +612,11 @@ impl Sub<usize> for LocalCodePtr {
     #[inline]
     fn sub(self, rhs: usize) -> Self::Output {
         match self {
-            LocalCodePtr::DirEntry(p) =>
+            LocalCodePtr::DirEntry(p) => p.checked_sub(rhs).map(LocalCodePtr::DirEntry),
-                p.checked_sub(rhs).map(LocalCodePtr::DirEntry),
+            LocalCodePtr::Halt => unreachable!(),
-            LocalCodePtr::Halt =>
+            LocalCodePtr::IndexingBuf(p, o, i) => i
-                unreachable!(),
+                .checked_sub(rhs)
-            LocalCodePtr::IndexingBuf(p, o, i) =>
+                .map(|r| LocalCodePtr::IndexingBuf(p, o, r)),
-                i.checked_sub(rhs).map(|r| LocalCodePtr::IndexingBuf(p, o, r)),
         }
     }
 }
@@ -720,15 +625,12 @@ impl SubAssign<usize> for LocalCodePtr {
     #[inline]
     fn sub_assign(&mut self, rhs: usize) {
         match self {
-            LocalCodePtr::DirEntry(ref mut p) =>
+            LocalCodePtr::DirEntry(ref mut p) => *p -= rhs,
-                *p -= rhs,
+            LocalCodePtr::Halt | LocalCodePtr::IndexingBuf(..) => unreachable!(),
-            LocalCodePtr::Halt | LocalCodePtr::IndexingBuf(..) =>
-                unreachable!(),
         }
     }
 }
 
-
 impl AddAssign<usize> for LocalCodePtr {
     #[inline]
     fn add_assign(&mut self, rhs: usize) {
@@ -746,14 +648,12 @@ impl Add<usize> for CodePtr {
 
     fn add(self, rhs: usize) -> Self::Output {
         match self {
-            p @ CodePtr::REPL(..) |
+            p @ CodePtr::REPL(..) | p @ CodePtr::VerifyAttrInterrupt(_) => {
-            p @ CodePtr::VerifyAttrInterrupt(_) => { // |
+                // |
-            // p @ CodePtr::DynamicTransaction(..) => {
+                // p @ CodePtr::DynamicTransaction(..) => {
                 p
             }
-            CodePtr::Local(local) => {
+            CodePtr::Local(local) => CodePtr::Local(local + rhs),
-                CodePtr::Local(local + rhs)
-            }
             CodePtr::BuiltInClause(_, local) | CodePtr::CallN(_, local, _) => {
                 CodePtr::Local(local + rhs)
             }
@@ -781,7 +681,6 @@ impl SubAssign<usize> for CodePtr {
     }
 }
 
-
 pub type HeapVarDict = IndexMap<Rc<Var>, Addr>;
 pub type AllocVarDict = IndexMap<Rc<Var>, VarData>;
 
@@ -821,29 +720,43 @@ impl Default for IndexStore {
 }
 
 impl IndexStore {
-    pub fn get_predicate_skeleton(
+    pub fn get_predicate_skeleton_mut(
         &mut self,
         compilation_target: &CompilationTarget,
         key: &PredicateKey,
     ) -> Option<&mut PredicateSkeleton> {
         match (key.0.as_str(), key.1) {
-            ("term_expansion", 2) => {
+            ("term_expansion", 2) => self.extensible_predicates.get_mut(key),
-                self.extensible_predicates.get_mut(key)
+            _ => match compilation_target {
-            }
+                CompilationTarget::User => self.extensible_predicates.get_mut(key),
-            _ => {
+                CompilationTarget::Module(ref module_name) => {
-                match compilation_target {
+                    if let Some(module) = self.modules.get_mut(module_name) {
-                    CompilationTarget::User => {
+                        module.extensible_predicates.get_mut(key)
-                        self.extensible_predicates.get_mut(key)
+                    } else {
-                    }
+                        None
-                    CompilationTarget::Module(ref module_name) => {
-                        if let Some(module) = self.modules.get_mut(module_name) {
-                            module.extensible_predicates.get_mut(key)
-                        } else {
-                            None
-                        }
                     }
                 }
-            }
+            },
+        }
+    }
+
+    pub fn get_predicate_skeleton(
+        &self,
+        compilation_target: &CompilationTarget,
+        key: &PredicateKey,
+    ) -> Option<&PredicateSkeleton> {
+        match (key.0.as_str(), key.1) {
+            ("term_expansion", 2) => self.extensible_predicates.get(key),
+            _ => match compilation_target {
+                CompilationTarget::User => self.extensible_predicates.get(key),
+                CompilationTarget::Module(ref module_name) => {
+                    if let Some(module) = self.modules.get(module_name) {
+                        module.extensible_predicates.get(key)
+                    } else {
+                        None
+                    }
+                }
+            },
         }
     }
 
@@ -855,19 +768,17 @@ impl IndexStore {
         match (key.0.as_str(), key.1) {
             ("term_expansion", 2) => {
                 self.extensible_predicates.remove(key);
-            },
+            }
-            _ => {
+            _ => match compilation_target {
-                match compilation_target {
+                CompilationTarget::User => {
-                    CompilationTarget::User => {
+                    self.extensible_predicates.remove(key);
-                        self.extensible_predicates.remove(key);
+                }
-                    }
+                CompilationTarget::Module(ref module_name) => {
-                    CompilationTarget::Module(ref module_name) => {
+                    if let Some(module) = self.modules.get_mut(module_name) {
-                        if let Some(module) = self.modules.get_mut(module_name) {
+                        module.extensible_predicates.remove(key);
-                            module.extensible_predicates.remove(key);
-                        }
                     }
                 }
-            }
+            },
         }
     }
 
@@ -880,15 +791,9 @@ impl IndexStore {
     ) -> Option<CodeIndex> {
         if module.as_str() == "user" {
             match ClauseType::from(name, arity, op_spec) {
-                ClauseType::Named(name, arity, _) => {
+                ClauseType::Named(name, arity, _) => self.code_dir.get(&(name, arity)).cloned(),
-                    self.code_dir.get(&(name, arity)).cloned()
+                ClauseType::Op(name, spec, ..) => self.code_dir.get(&(name, spec.arity())).cloned(),
-                }
+                _ => None,
-                ClauseType::Op(name, spec, ..) => {
-                    self.code_dir.get(&(name, spec.arity())).cloned()
-                }
-                _ => {
-                    None
-                }
             }
         } else {
             self.modules.get(&module).and_then(|module| {
@@ -899,9 +804,7 @@ impl IndexStore {
                     ClauseType::Op(name, spec, ..) => {
                         module.code_dir.get(&(name, spec.arity())).cloned()
                     }
-                    _ => {
+                    _ => None,
-                        None
-                    }
                 }
             })
         }
@@ -914,44 +817,32 @@ impl IndexStore {
         compilation_target: &CompilationTarget,
     ) -> Option<&Vec<MetaSpec>> {
         match compilation_target {
-            CompilationTarget::User => {
+            CompilationTarget::User => self.meta_predicates.get(&(name, arity)),
-                self.meta_predicates.get(&(name, arity))
+            CompilationTarget::Module(ref module_name) => match self.modules.get(module_name) {
-            }
+                Some(ref module) => module
-            CompilationTarget::Module(ref module_name) => {
+                    .meta_predicates
-                match self.modules.get(module_name) {
+                    .get(&(name.clone(), arity))
-                    Some(ref module) => {
+                    .or_else(|| self.meta_predicates.get(&(name, arity))),
-                        module.meta_predicates.get(&(name.clone(), arity))
+                None => self.meta_predicates.get(&(name, arity)),
-                              .or_else(|| {
+            },
-                                  self.meta_predicates.get(&(name, arity))
-                              })
-                    }
-                    None => {
-                        self.meta_predicates.get(&(name, arity))
-                    }
-                }
-            }
         }
     }
 
     pub fn is_dynamic_predicate(&self, module_name: ClauseName, key: PredicateKey) -> bool {
         match module_name.as_str() {
-            "user" => {
+            "user" => self
-                self.extensible_predicates.get(&key)
+                .extensible_predicates
+                .get(&key)
+                .map(|skeleton| skeleton.is_dynamic)
+                .unwrap_or(false),
+            _ => match self.modules.get(&module_name) {
+                Some(ref module) => module
+                    .extensible_predicates
+                    .get(&key)
                     .map(|skeleton| skeleton.is_dynamic)
-                    .unwrap_or(false)
+                    .unwrap_or(false),
-            }
+                None => false,
-            _ => {
+            },
-                match self.modules.get(&module_name) {
-                    Some(ref module) => {
-                        module.extensible_predicates.get(&key)
-                              .map(|skeleton| skeleton.is_dynamic)
-                              .unwrap_or(false)
-                    }
-                    None => {
-                        false
-                    }
-                }
-            }
         }
     }
 
@@ -960,8 +851,7 @@ impl IndexStore {
         IndexStore::default()
     }
 
-    pub(super)
+    pub(super) fn get_cleaner_sites(&self) -> (usize, usize) {
-    fn get_cleaner_sites(&self) -> (usize, usize) {
         let r_w_h = clause_name!("run_cleaners_with_handling");
         let r_wo_h = clause_name!("run_cleaners_without_handling");
         let iso_ext = clause_name!("iso_ext");
@@ -993,10 +883,8 @@ pub enum RefOrOwned<'a, T: 'a> {
 impl<'a, T: 'a + fmt::Debug> fmt::Debug for RefOrOwned<'a, T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
-            &RefOrOwned::Borrowed(ref borrowed) =>
+            &RefOrOwned::Borrowed(ref borrowed) => write!(f, "Borrowed({:?})", borrowed),
-                write!(f, "Borrowed({:?})", borrowed),
+            &RefOrOwned::Owned(ref owned) => write!(f, "Owned({:?})", owned),
-            &RefOrOwned::Owned(ref owned) =>
-                write!(f, "Owned({:?})", owned),
         }
     }
 }
@@ -1009,7 +897,9 @@ impl<'a, T> RefOrOwned<'a, T> {
         }
     }
 
-    pub fn to_owned(self) -> T where T: Clone
+    pub fn to_owned(self) -> T
+    where
+        T: Clone,
     {
         match self {
             RefOrOwned::Borrowed(item) => item.clone(),

src/machine/machine_state.rs

@@ -1,5 +1,6 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
-use crate::prolog_parser_rebis::tabled_rc::*;
+use prolog_parser::tabled_rc::*;
+use prolog_parser::{clause_name, temp_v};
 
 use crate::clause_types::*;
 use crate::forms::*;
@@ -14,9 +15,11 @@ use crate::machine::stack::*;
 use crate::machine::streams::*;
 use crate::rug::Integer;
 
-use crate::downcast::Any;
+use downcast::{
+    downcast, downcast_methods, downcast_methods_core, downcast_methods_std, impl_downcast, Any,
+};
 
-use crate::indexmap::IndexMap;
+use indexmap::IndexMap;
 
 use std::cmp::Ordering;
 use std::convert::TryFrom;
@@ -32,33 +35,26 @@ pub struct Ball {
 }
 
 impl Ball {
-    pub(super)
+    pub(super) fn new() -> Self {
-    fn new() -> Self {
         Ball {
             boundary: 0,
             stub: Heap::new(),
         }
     }
 
-    pub(super)
+    pub(super) fn reset(&mut self) {
-    fn reset(&mut self) {
         self.boundary = 0;
         self.stub.clear();
     }
 
-    pub(super)
+    pub(super) fn copy_and_align(&self, h: usize) -> Heap {
-    fn copy_and_align(&self, h: usize) -> Heap {
         let diff = self.boundary as i64 - h as i64;
         let mut stub = Heap::new();
 
         for heap_value in self.stub.iter_from(0) {
             stub.push(match heap_value {
-                &HeapCellValue::Addr(addr) => {
+                &HeapCellValue::Addr(addr) => HeapCellValue::Addr(addr - diff),
-                    HeapCellValue::Addr(addr - diff)
+                heap_value => heap_value.context_free_clone(),
-                }
-                heap_value => {
-                    heap_value.context_free_clone()
-                }
             });
         }
 
@@ -123,11 +119,7 @@ pub(super) struct CopyBallTerm<'a> {
 }
 
 impl<'a> CopyBallTerm<'a> {
-    pub(super) fn new(
+    pub(super) fn new(stack: &'a mut Stack, heap: &'a mut Heap, stub: &'a mut Heap) -> Self {
-        stack: &'a mut Stack,
-        heap: &'a mut Heap,
-        stub: &'a mut Heap,
-    ) -> Self {
         let hb = heap.h();
 
         CopyBallTerm {
@@ -182,12 +174,8 @@ impl<'a> CopierTarget for CopyBallTerm<'a> {
                 let index = h - self.heap_boundary;
                 self.stub[index].as_addr(h)
             }
-            Addr::StackCell(fr, sc) => {
+            Addr::StackCell(fr, sc) => self.stack.index_and_frame(fr)[sc],
-                self.stack.index_and_frame(fr)[sc]
+            addr => addr,
-            }
-            addr => {
-                addr
-            }
         }
     }
 
@@ -226,9 +214,7 @@ impl Index<RegType> for MachineState {
 impl IndexMut<RegType> for MachineState {
     fn index_mut(&mut self, reg: RegType) -> &mut Self::Output {
         match reg {
-            RegType::Temp(temp) => {
+            RegType::Temp(temp) => &mut self.registers[temp],
-                &mut self.registers[temp]
-            }
             RegType::Perm(perm) => {
                 let e = self.e;
 
@@ -255,15 +241,12 @@ pub(super) enum HeapPtr {
 
 impl HeapPtr {
     #[inline]
-    pub(super)
+    pub(super) fn read(&self, heap: &Heap) -> Addr {
-    fn read(&self, heap: &Heap) -> Addr {
         match self {
-            &HeapPtr::HeapCell(h) => {
+            &HeapPtr::HeapCell(h) => Addr::HeapCell(h),
-                Addr::HeapCell(h)
-            }
             &HeapPtr::PStrChar(h, n) => {
                 if let &HeapCellValue::PartialString(ref pstr, has_tail) = &heap[h] {
-                    if let Some(c) = pstr.range_from(n ..).next() {
+                    if let Some(c) = pstr.range_from(n..).next() {
                         Addr::Char(c)
                     } else if has_tail {
                         Addr::HeapCell(h + 1)
@@ -274,9 +257,7 @@ impl HeapPtr {
                     unreachable!()
                 }
             }
-            &HeapPtr::PStrLocation(h, n) => {
+            &HeapPtr::PStrLocation(h, n) => Addr::PStrLocation(h, n),
-                Addr::PStrLocation(h, n)
-            }
         }
     }
 }
@@ -313,16 +294,11 @@ pub struct MachineState {
     pub(super) last_call: bool,
     pub(crate) heap_locs: HeapVarDict,
     pub(crate) flags: MachineFlags,
-    pub(crate) at_end_of_expansion: bool
+    pub(crate) at_end_of_expansion: bool,
 }
 
 impl MachineState {
-    pub(crate)
+    pub(crate) fn read_term(&mut self, mut stream: Stream, indices: &mut IndexStore) -> CallResult {
-    fn read_term(
-        &mut self,
-        mut stream: Stream,
-        indices: &mut IndexStore,
-    ) -> CallResult {
         self.check_stream_properties(
             &mut stream,
             StreamType::Text,
@@ -342,11 +318,7 @@ impl MachineState {
         let mut orig_stream = stream.clone();
 
         loop {
-            match self.read(
+            match self.read(stream.clone(), self.atom_tbl.clone(), &indices.op_dir) {
-                stream.clone(),
-                self.atom_tbl.clone(),
-                &indices.op_dir,
-            ) {
                 Ok(term_write_result) => {
                     let term = self[temp_v!(2)];
                     self.unify(Addr::HeapCell(term_write_result.heap_loc), term);
@@ -363,7 +335,8 @@ impl MachineState {
                         let h = self.heap.h();
                         let spec = fetch_atom_op_spec(clause_name!("="), None, &indices.op_dir);
 
-                        self.heap.push(HeapCellValue::NamedStr(2, clause_name!("="), spec));
+                        self.heap
+                            .push(HeapCellValue::NamedStr(2, clause_name!("="), spec));
                         self.heap.push(HeapCellValue::Atom(var_atom, None));
                         self.heap.push(HeapCellValue::Addr(binding));
 
@@ -406,8 +379,7 @@ impl MachineState {
                     }
 
                     let vars_addr = self[temp_v!(4)];
-                    let vars_offset =
+                    let vars_offset = Addr::HeapCell(self.heap.to_list(var_list.into_iter()));
-                        Addr::HeapCell(self.heap.to_list(var_list.into_iter()));
 
                     self.unify(vars_offset, vars_addr);
 
@@ -427,7 +399,7 @@ impl MachineState {
                             self[temp_v!(2)],
                             &mut orig_stream,
                             clause_name!("read_term"),
-                            3
+                            3,
                         )?;
 
                         if orig_stream.options.eof_action == EOFAction::Reset {
@@ -448,12 +420,10 @@ impl MachineState {
         }
     }
 
-    pub(crate)
+    pub(crate) fn write_term<'a>(
-    fn write_term<'a>(
         &'a self,
         op_dir: &'a OpDir,
-    ) -> Result<Option<HCPrinter<'a, PrinterOutputter>>, MachineStub>
+    ) -> Result<Option<HCPrinter<'a, PrinterOutputter>>, MachineStub> {
-    {
         let ignore_ops = self.store(self.deref(self[temp_v!(3)]));
         let numbervars = self.store(self.deref(self[temp_v!(4)]));
         let quoted = self.store(self.deref(self[temp_v!(5)]));
@@ -462,7 +432,7 @@ impl MachineState {
         let mut printer = HCPrinter::new(&self, op_dir, PrinterOutputter::new());
 
         if let &Addr::Con(h) = &ignore_ops {
-	        if let HeapCellValue::Atom(ref name, _) = &self.heap[h] {
+            if let HeapCellValue::Atom(ref name, _) = &self.heap[h] {
                 printer.ignore_ops = name.as_str() == "true";
             } else {
                 unreachable!()
@@ -470,7 +440,7 @@ impl MachineState {
         }
 
         if let &Addr::Con(h) = &numbervars {
-	        if let HeapCellValue::Atom(ref name, _) = &self.heap[h] {
+            if let HeapCellValue::Atom(ref name, _) = &self.heap[h] {
                 printer.numbervars = name.as_str() == "true";
             } else {
                 unreachable!()
@@ -478,7 +448,7 @@ impl MachineState {
         }
 
         if let &Addr::Con(h) = &quoted {
-	        if let HeapCellValue::Atom(ref name, _) = &self.heap[h] {
+            if let HeapCellValue::Atom(ref name, _) = &self.heap[h] {
                 printer.quoted = name.as_str() == "true";
             } else {
                 unreachable!()
@@ -514,9 +484,7 @@ impl MachineState {
                 for addr in addrs {
                     match addr {
                         Addr::Str(s) => match &self.heap[s] {
-                            &HeapCellValue::NamedStr(2, ref name, _)
+                            &HeapCellValue::NamedStr(2, ref name, _) if name.as_str() == "=" => {
-                                if name.as_str() == "=" =>
-                            {
                                 let atom = self.heap[s + 1].as_addr(s + 1);
                                 let var = self.heap[s + 2].as_addr(s + 2);
 
@@ -540,11 +508,9 @@ impl MachineState {
 
                                 var_names.insert(var, atom);
                             }
-                            _ => {
+                            _ => {}
-                            }
                         },
-                        _ => {
+                        _ => {}
-                        }
                     }
                 }
 
@@ -558,8 +524,7 @@ impl MachineState {
         Ok(Some(printer))
     }
 
-    pub(super)
+    pub(super) fn throw_undefined_error(&mut self, name: ClauseName, arity: usize) -> MachineStub {
-    fn throw_undefined_error(&mut self, name: ClauseName, arity: usize) -> MachineStub {
         let stub = MachineError::functor_stub(name.clone(), arity);
         let h = self.heap.h();
         let key = ExistenceError::Procedure(name, arity);
@@ -568,13 +533,11 @@ impl MachineState {
     }
 
     #[inline]
-    pub(crate)
+    pub(crate) fn heap_pstr_iter<'a>(&'a self, focus: Addr) -> HeapPStrIter<'a> {
-    fn heap_pstr_iter<'a>(&'a self, focus: Addr) -> HeapPStrIter<'a> {
         HeapPStrIter::new(self, focus)
     }
 
-    pub(super)
+    pub(super) fn try_char_list(&self, addrs: Vec<Addr>) -> Result<String, MachineError> {
-    fn try_char_list(&self, addrs: Vec<Addr>) -> Result<String, MachineError> {
         let mut chars = String::new();
         let mut iter = addrs.iter();
 
@@ -594,55 +557,46 @@ impl MachineState {
                         }
                     }
                 }
-                _ => {
+                _ => {}
-                }
             };
 
             let h = self.heap.h();
 
-            return Err(
+            return Err(MachineError::type_error(h, ValidType::Character, addr));
-                MachineError::type_error(h, ValidType::Character, addr)
-            );
         }
 
         Ok(chars)
     }
 
-    pub(super)
+    pub(super) fn read_predicate_key(&self, name: Addr, arity: Addr) -> (ClauseName, usize) {
-    fn read_predicate_key(&self, name: Addr, arity: Addr) -> (ClauseName, usize) {
         let predicate_name = atom_from!(self, self.store(self.deref(name)));
         let arity = self.store(self.deref(arity));
 
-        let arity =
+        let arity = match Number::try_from((arity, &self.heap)) {
-            match Number::try_from((arity, &self.heap)) {
+            Ok(Number::Integer(n)) if &*n >= &0 && &*n <= &MAX_ARITY => n.to_usize().unwrap(),
-                Ok(Number::Integer(n)) if &*n >= &0 && &*n <= &MAX_ARITY =>
+            Ok(Number::Fixnum(n)) if n >= 0 && n <= MAX_ARITY as isize => {
-                    n.to_usize().unwrap(),
+                usize::try_from(n).unwrap()
-                Ok(Number::Fixnum(n)) if n >= 0 && n <= MAX_ARITY as isize =>
+            }
-                    usize::try_from(n).unwrap(),
+            _ => unreachable!(),
-                _ =>
+        };
-                    unreachable!()
-            };
 
         (predicate_name, arity)
     }
 
-    pub(super)
+    pub(super) fn call_at_index(&mut self, arity: usize, p: LocalCodePtr) {
-    fn call_at_index(&mut self, arity: usize, p: LocalCodePtr) {
         self.cp.assign_if_local(self.p.clone() + 1);
         self.num_of_args = arity;
         self.b0 = self.b;
         self.p = CodePtr::Local(p);
     }
 
-    pub(super)
+    pub(super) fn execute_at_index(&mut self, arity: usize, p: LocalCodePtr) {
-    fn execute_at_index(&mut self, arity: usize, p: LocalCodePtr) {
         self.num_of_args = arity;
         self.b0 = self.b;
         self.p = CodePtr::Local(p);
     }
 
-    pub(super)
+    pub(super) fn module_lookup(
-    fn module_lookup(
         &mut self,
         indices: &IndexStore,
         call_policy: &mut Box<dyn CallPolicy>,
@@ -687,10 +641,15 @@ pub(crate) type CallResult = Result<(), Vec<HeapCellValue>>;
 pub(crate) trait CallPolicy: Any + fmt::Debug {
     fn retry_me_else(&mut self, machine_st: &mut MachineState, offset: usize) -> CallResult {
         let b = machine_st.b;
-        let n = machine_st.stack.index_or_frame(b).prelude.univ_prelude.num_cells;
+        let n = machine_st
+            .stack
+            .index_or_frame(b)
+            .prelude
+            .univ_prelude
+            .num_cells;
 
-        for i in 1 .. n + 1 {
+        for i in 1..n + 1 {
-            machine_st.registers[i] = machine_st.stack.index_or_frame(b)[i-1];
+            machine_st.registers[i] = machine_st.stack.index_or_frame(b)[i - 1];
         }
 
         machine_st.num_of_args = n;
@@ -706,17 +665,24 @@ pub(crate) trait CallPolicy: Any + fmt::Debug {
         machine_st.tr = machine_st.stack.index_or_frame(b).prelude.tr;
 
         machine_st.trail.truncate(machine_st.tr);
-        machine_st.heap.truncate(machine_st.stack.index_or_frame(b).prelude.h);
+        machine_st
+            .heap
+            .truncate(machine_st.stack.index_or_frame(b).prelude.h);
 
-        let attr_var_init_queue_b =
+        let attr_var_init_queue_b = machine_st
-            machine_st.stack.index_or_frame(b).prelude.attr_var_init_queue_b;
+            .stack
-        let attr_var_init_bindings_b =
+            .index_or_frame(b)
-            machine_st.stack.index_or_frame(b).prelude.attr_var_init_bindings_b;
+            .prelude
+            .attr_var_init_queue_b;
+        let attr_var_init_bindings_b = machine_st
+            .stack
+            .index_or_frame(b)
+            .prelude
+            .attr_var_init_bindings_b;
 
-        machine_st.attr_var_init.backtrack(
+        machine_st
-            attr_var_init_queue_b,
+            .attr_var_init
-            attr_var_init_bindings_b,
+            .backtrack(attr_var_init_queue_b, attr_var_init_bindings_b);
-        );
 
         machine_st.hb = machine_st.heap.h();
         machine_st.p += 1;
@@ -726,10 +692,15 @@ pub(crate) trait CallPolicy: Any + fmt::Debug {
 
     fn retry(&mut self, machine_st: &mut MachineState, offset: usize) -> CallResult {
         let b = machine_st.b;
-        let n = machine_st.stack.index_or_frame(b).prelude.univ_prelude.num_cells;
+        let n = machine_st
+            .stack
+            .index_or_frame(b)
+            .prelude
+            .univ_prelude
+            .num_cells;
 
-        for i in 1 .. n + 1 {
+        for i in 1..n + 1 {
-            machine_st.registers[i] = machine_st.stack.index_or_frame(b)[i-1];
+            machine_st.registers[i] = machine_st.stack.index_or_frame(b)[i - 1];
         }
 
         machine_st.num_of_args = n;
@@ -745,14 +716,24 @@ pub(crate) trait CallPolicy: Any + fmt::Debug {
         machine_st.tr = machine_st.stack.index_or_frame(b).prelude.tr;
 
         machine_st.trail.truncate(machine_st.tr);
-        machine_st.heap.truncate(machine_st.stack.index_or_frame(b).prelude.h);
+        machine_st
+            .heap
+            .truncate(machine_st.stack.index_or_frame(b).prelude.h);
 
-        let attr_var_init_queue_b =
+        let attr_var_init_queue_b = machine_st
-            machine_st.stack.index_or_frame(b).prelude.attr_var_init_queue_b;
+            .stack
-        let attr_var_init_bindings_b =
+            .index_or_frame(b)
-            machine_st.stack.index_or_frame(b).prelude.attr_var_init_bindings_b;
+            .prelude
+            .attr_var_init_queue_b;
+        let attr_var_init_bindings_b = machine_st
+            .stack
+            .index_or_frame(b)
+            .prelude
+            .attr_var_init_bindings_b;
 
-        machine_st.attr_var_init.backtrack(attr_var_init_queue_b, attr_var_init_bindings_b);
+        machine_st
+            .attr_var_init
+            .backtrack(attr_var_init_queue_b, attr_var_init_bindings_b);
 
         machine_st.hb = machine_st.heap.h();
         machine_st.p = CodePtr::Local(dir_entry!(machine_st.p.local().abs_loc() + offset));
@@ -762,10 +743,15 @@ pub(crate) trait CallPolicy: Any + fmt::Debug {
 
     fn trust(&mut self, machine_st: &mut MachineState, offset: usize) -> CallResult {
         let b = machine_st.b;
-        let n = machine_st.stack.index_or_frame(b).prelude.univ_prelude.num_cells;
+        let n = machine_st
+            .stack
+            .index_or_frame(b)
+            .prelude
+            .univ_prelude
+            .num_cells;
 
-        for i in 1 .. n + 1 {
+        for i in 1..n + 1 {
-            machine_st.registers[i] = machine_st.stack.index_or_frame(b)[i-1];
+            machine_st.registers[i] = machine_st.stack.index_or_frame(b)[i - 1];
         }
 
         machine_st.num_of_args = n;
@@ -779,17 +765,24 @@ pub(crate) trait CallPolicy: Any + fmt::Debug {
         machine_st.tr = machine_st.stack.index_or_frame(b).prelude.tr;
 
         machine_st.trail.truncate(machine_st.tr);
-        machine_st.heap.truncate(machine_st.stack.index_or_frame(b).prelude.h);
+        machine_st
+            .heap
+            .truncate(machine_st.stack.index_or_frame(b).prelude.h);
 
-        let attr_var_init_queue_b =
+        let attr_var_init_queue_b = machine_st
-            machine_st.stack.index_or_frame(b).prelude.attr_var_init_queue_b;
+            .stack
-        let attr_var_init_bindings_b =
+            .index_or_frame(b)
-            machine_st.stack.index_or_frame(b).prelude.attr_var_init_bindings_b;
+            .prelude
+            .attr_var_init_queue_b;
+        let attr_var_init_bindings_b = machine_st
+            .stack
+            .index_or_frame(b)
+            .prelude
+            .attr_var_init_bindings_b;
 
-        machine_st.attr_var_init.backtrack(
+        machine_st
-            attr_var_init_queue_b,
+            .attr_var_init
-            attr_var_init_bindings_b,
+            .backtrack(attr_var_init_queue_b, attr_var_init_bindings_b);
-        );
 
         machine_st.b = machine_st.stack.index_or_frame(b).prelude.b;
         machine_st.stack.truncate(b);
@@ -802,10 +795,15 @@ pub(crate) trait CallPolicy: Any + fmt::Debug {
 
     fn trust_me(&mut self, machine_st: &mut MachineState) -> CallResult {
         let b = machine_st.b;
-        let n = machine_st.stack.index_or_frame(b).prelude.univ_prelude.num_cells;
+        let n = machine_st
+            .stack
+            .index_or_frame(b)
+            .prelude
+            .univ_prelude
+            .num_cells;
 
-        for i in 1 .. n + 1 {
+        for i in 1..n + 1 {
-            machine_st.registers[i] = machine_st.stack.index_or_frame(b)[i-1];
+            machine_st.registers[i] = machine_st.stack.index_or_frame(b)[i - 1];
         }
 
         machine_st.num_of_args = n;
@@ -819,17 +817,24 @@ pub(crate) trait CallPolicy: Any + fmt::Debug {
         machine_st.tr = machine_st.stack.index_or_frame(b).prelude.tr;
 
         machine_st.trail.truncate(machine_st.tr);
-        machine_st.heap.truncate(machine_st.stack.index_or_frame(b).prelude.h);
+        machine_st
+            .heap
+            .truncate(machine_st.stack.index_or_frame(b).prelude.h);
 
-        let attr_var_init_queue_b =
+        let attr_var_init_queue_b = machine_st
-            machine_st.stack.index_or_frame(b).prelude.attr_var_init_queue_b;
+            .stack
-        let attr_var_init_bindings_b =
+            .index_or_frame(b)
-            machine_st.stack.index_or_frame(b).prelude.attr_var_init_bindings_b;
+            .prelude
+            .attr_var_init_queue_b;
+        let attr_var_init_bindings_b = machine_st
+            .stack
+            .index_or_frame(b)
+            .prelude
+            .attr_var_init_bindings_b;
 
-        machine_st.attr_var_init.backtrack(
+        machine_st
-            attr_var_init_queue_b,
+            .attr_var_init
-            attr_var_init_bindings_b,
+            .backtrack(attr_var_init_queue_b, attr_var_init_bindings_b);
-        );
 
         machine_st.b = machine_st.stack.index_or_frame(b).prelude.b;
         machine_st.stack.truncate(b);
@@ -928,13 +933,13 @@ pub(crate) trait CallPolicy: Any + fmt::Debug {
                     Addr::Con(h) if machine_st.heap.atom_at(h) => {
                         if let HeapCellValue::Atom(ref atom, _) = &machine_st.heap[h] {
                             match atom.as_str() {
-                                ">" | "<" | "=" => {
+                                ">" | "<" | "=" => {}
-                                }
                                 _ => {
                                     let stub =
                                         MachineError::functor_stub(clause_name!("compare"), 3);
 
-                                    let err = MachineError::domain_error(DomainErrorType::Order, a1);
+                                    let err =
+                                        MachineError::domain_error(DomainErrorType::Order, a1);
                                     return Err(machine_st.error_form(err, stub));
                                 }
                             }
@@ -948,8 +953,7 @@ pub(crate) trait CallPolicy: Any + fmt::Debug {
                         let err = MachineError::type_error(h, ValidType::Atom, a1);
                         return Err(machine_st.error_form(err, stub));
                     }
-                    _ => {
+                    _ => {}
-                    }
                 }
 
                 let atom = match machine_st.compare_term_test(&a2, &a3) {
@@ -998,9 +1002,7 @@ pub(crate) trait CallPolicy: Any + fmt::Debug {
                         let addr = machine_st[temp_v!(1)];
                         let eof = clause_name!("end_of_file".to_string(), machine_st.atom_tbl);
 
-                        let atom = machine_st.heap.to_unifiable(
+                        let atom = machine_st.heap.to_unifiable(HeapCellValue::Atom(eof, None));
-                            HeapCellValue::Atom(eof, None)
-                        );
 
                         machine_st.unify(addr, atom);
                     }
@@ -1056,7 +1058,9 @@ pub(crate) trait CallPolicy: Any + fmt::Debug {
                 let mut list = machine_st.try_from_list(temp_v!(1), stub)?;
 
                 list.sort_unstable_by(|a1, a2| {
-                    machine_st.compare_term_test(a1, a2).unwrap_or(Ordering::Less)
+                    machine_st
+                        .compare_term_test(a1, a2)
+                        .unwrap_or(Ordering::Less)
                 });
 
                 machine_st.term_dedup(&mut list);
@@ -1081,7 +1085,9 @@ pub(crate) trait CallPolicy: Any + fmt::Debug {
                 }
 
                 key_pairs.sort_by(|a1, a2| {
-                    machine_st.compare_term_test(&a1.0, &a2.0).unwrap_or(Ordering::Less)
+                    machine_st
+                        .compare_term_test(&a1.0, &a2.0)
+                        .unwrap_or(Ordering::Less)
                 });
 
                 let key_pairs = key_pairs.into_iter().map(|kp| kp.1);
@@ -1155,11 +1161,7 @@ pub(crate) trait CallPolicy: Any + fmt::Debug {
                 let stub = MachineError::functor_stub(clause_name!("call"), arity + 1);
 
                 return Err(machine_st.error_form(
-                    MachineError::type_error(
+                    MachineError::type_error(machine_st.heap.h(), ValidType::Callable, name),
-                        machine_st.heap.h(),
-                        ValidType::Callable,
-                        name
-                    ),
                     stub,
                 ));
             }
@@ -1200,7 +1202,8 @@ impl CallPolicy for CWILCallPolicy {
         arity: usize,
         idx: &CodeIndex,
     ) -> CallResult {
-        self.prev_policy.context_call(machine_st, name, arity, idx)?;//, indices)?;
+        self.prev_policy
+            .context_call(machine_st, name, arity, idx)?; //, indices)?;
         self.increment(machine_st)
     }
 
@@ -1239,7 +1242,7 @@ impl CallPolicy for CWILCallPolicy {
             code_dir,
             op_dir,
             current_input_stream,
-            current_output_stream
+            current_output_stream,
         )?;
 
         self.increment(machine_st)
@@ -1283,8 +1286,7 @@ pub(crate) struct CWILCallPolicy {
 }
 
 impl CWILCallPolicy {
-    pub(crate)
+    pub(crate) fn new_in_place(policy: &mut Box<dyn CallPolicy>) {
-    fn new_in_place(policy: &mut Box<dyn CallPolicy>) {
         let mut prev_policy: Box<dyn CallPolicy> = Box::new(DefaultCallPolicy {});
         mem::swap(&mut prev_policy, policy);
 
@@ -1319,8 +1321,7 @@ impl CWILCallPolicy {
         Ok(())
     }
 
-    pub(crate)
+    pub(crate) fn add_limit(&mut self, mut limit: Integer, b: usize) -> &Integer {
-    fn add_limit(&mut self, mut limit: Integer, b: usize) -> &Integer {
         limit += &self.count;
 
         match self.limits.last().cloned() {
@@ -1331,8 +1332,7 @@ impl CWILCallPolicy {
         &self.count
     }
 
-    pub(crate)
+    pub(crate) fn remove_limit(&mut self, b: usize) -> &Integer {
-    fn remove_limit(&mut self, b: usize) -> &Integer {
         if let Some((_, bp)) = self.limits.last().cloned() {
             if bp == b {
                 self.limits.pop();
@@ -1342,13 +1342,11 @@ impl CWILCallPolicy {
         &self.count
     }
 
-    pub(crate)
+    pub(crate) fn is_empty(&self) -> bool {
-    fn is_empty(&self) -> bool {
         self.limits.is_empty()
     }
 
-    pub(crate)
+    pub(crate) fn into_inner(&mut self) -> Box<dyn CallPolicy> {
-    fn into_inner(&mut self) -> Box<dyn CallPolicy> {
         let mut new_inner: Box<dyn CallPolicy> = Box::new(DefaultCallPolicy {});
         mem::swap(&mut self.prev_policy, &mut new_inner);
         new_inner
@@ -1369,7 +1367,6 @@ fn cut_body(machine_st: &mut MachineState, addr: &Addr) -> bool {
         &Addr::CutPoint(b0) | &Addr::Usize(b0) => {
             if b > b0 {
                 machine_st.b = b0;
-                machine_st.tidy_trail();
             }
         }
         _ => {
@@ -1457,7 +1454,6 @@ impl CutPolicy for SCCCutPolicy {
             Addr::Usize(b0) | Addr::CutPoint(b0) => {
                 if b > b0 {
                     machine_st.b = b0;
-                    machine_st.tidy_trail();
                 }
             }
             _ => {

src/machine/mod.rs

@@ -1,5 +1,8 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
-use crate::prolog_parser_rebis::tabled_rc::*;
+use prolog_parser::tabled_rc::*;
+use prolog_parser::{clause_name, temp_v};
+
+use lazy_static::lazy_static;
 
 use crate::clause_types::*;
 use crate::forms::*;
@@ -34,17 +37,18 @@ mod machine_state_impl;
 mod system_calls;
 
 //use crate::machine::attributed_variables::*;
-use crate::machine::compile::*;
 use crate::machine::code_repo::*;
+use crate::machine::compile::*;
 // use crate::machine::loader::*;
 use crate::machine::machine_errors::*;
 use crate::machine::machine_indices::*;
 use crate::machine::machine_state::*;
 use crate::machine::streams::*;
 
-use crate::indexmap::IndexMap;
+use indexmap::IndexMap;
 
 //use std::convert::TryFrom;
+use prolog_parser::ast::ClauseName;
 use std::fs::File;
 use std::mem;
 use std::path::PathBuf;
@@ -119,39 +123,6 @@ include!(concat!(env!("OUT_DIR"), "/libraries.rs"));
 
 impl Machine {
     /*
-    fn compile_special_forms(&mut self)
-    {
-        let verify_attrs_src = ListingSource::User;
-
-        match compile_special_form(
-            self,
-            Stream::from(VERIFY_ATTRS),
-            verify_attrs_src,
-        )
-        {
-            Ok(p) => {
-                self.machine_st.attr_var_init.verify_attrs_loc = p;
-            }
-            Err(_) =>
-                panic!("Machine::compile_special_forms() failed at VERIFY_ATTRS"),
-        }
-
-        let project_attrs_src = ListingSource::User;
-
-        match compile_special_form(
-            self,
-            Stream::from(PROJECT_ATTRS),
-            project_attrs_src,
-        )
-        {
-            Ok(p) => {
-                self.machine_st.attr_var_init.project_attrs_loc = p;
-            }
-            Err(e) =>
-                panic!("Machine::compile_special_forms() failed at PROJECT_ATTRS: {}", e),
-        }
-    }
-
     fn compile_scryerrc(&mut self) {
         let mut path = match dirs_next::home_dir() {
             Some(path) => path,
@@ -177,13 +148,7 @@ impl Machine {
             compile_user_module(self, file_src, rc_src);
         }
     }
-*/
+    */
-    #[cfg(test)]
-    pub fn reset(&mut self) {
-        self.current_input_stream = readline::input_stream();
-        self.policies.cut_policy = Box::new(DefaultCutPolicy {});
-        self.machine_st.reset();
-    }
 
     fn run_module_predicate(&mut self, module_name: ClauseName, key: PredicateKey) {
         if let Some(module) = self.indices.modules.get(&module_name) {
@@ -201,18 +166,13 @@ impl Machine {
     }
 
     fn load_file(&mut self, path: String, stream: Stream) {
-        self.machine_st[temp_v!(1)] = Addr::Stream(
+        self.machine_st[temp_v!(1)] =
-            self.machine_st.heap.push(HeapCellValue::Stream(
+            Addr::Stream(self.machine_st.heap.push(HeapCellValue::Stream(stream)));
-                stream,
-            ))
-        );
 
-        self.machine_st[temp_v!(2)] = Addr::Con(
+        self.machine_st[temp_v!(2)] = Addr::Con(self.machine_st.heap.push(HeapCellValue::Atom(
-            self.machine_st.heap.push(HeapCellValue::Atom(
+            clause_name!(path, self.machine_st.atom_tbl),
-                clause_name!(path, self.machine_st.atom_tbl),
+            None,
-                None,
+        )));
-            ))
-        );
 
         self.run_module_predicate(clause_name!("loader"), (clause_name!("file_load"), 2));
     }
@@ -245,11 +205,9 @@ impl Machine {
         bootstrapping_compile(
             Stream::from(include_str!("attributed_variables.pl")),
             self,
-            ListingSource::from_file_and_path(
+            ListingSource::from_file_and_path(clause_name!("attributed_variables"), path_buf),
-                clause_name!("attributed_variables"),
+        )
-                path_buf,
+        .unwrap();
-            ),
-        ).unwrap();
 
         let mut path_buf = current_dir();
         path_buf.push("machine/project_attributes.pl");
@@ -257,11 +215,9 @@ impl Machine {
         bootstrapping_compile(
             Stream::from(include_str!("project_attributes.pl")),
             self,
-            ListingSource::from_file_and_path(
+            ListingSource::from_file_and_path(clause_name!("project_attributes"), path_buf),
-                clause_name!("project_attributes"),
+        )
-                path_buf,
+        .unwrap();
-            ),
-        ).unwrap();
 
         if let Some(module) = self.indices.modules.get(&clause_name!("$atts")) {
             if let Some(code_index) = module.code_dir.get(&(clause_name!("driver"), 2)) {
@@ -289,15 +245,66 @@ impl Machine {
 
         self.machine_st[temp_v!(1)] = list_addr;
 
-        // WAS:
+        self.run_module_predicate(clause_name!("$toplevel"), (clause_name!("$repl"), 1));
-        // self.run_module_predicate(clause_name!("$toplevel"), (clause_name!("$repl"), 1));
-
-        self.run_module_predicate(clause_name!("$toplevel"), (clause_name!("repl"), 0));
     }
 
-    pub fn new(user_input: Stream, user_output: Stream) -> Self
+    fn configure_modules(&mut self) {
-    {
+        fn update_call_n_indices(loader: &Module, target_module: &mut Module) {
-        use crate::ref_thread_local::RefThreadLocal;
+            for arity in 1..66 {
+                let key = (clause_name!("call"), arity);
+
+                match loader.code_dir.get(&key) {
+                    Some(src_code_index) => {
+                        let target_code_index = target_module
+                            .code_dir
+                            .entry(key.clone())
+                            .or_insert_with(|| CodeIndex::new(IndexPtr::Undefined));
+
+                        target_code_index.set(src_code_index.get());
+                    }
+                    None => {
+                        unreachable!();
+                    }
+                }
+            }
+        }
+
+        if let Some(loader) = self.indices.modules.swap_remove(&clause_name!("loader")) {
+            if let Some(builtins) = self.indices.modules.get_mut(&clause_name!("builtins")) {
+                // Import loader's exports into the builtins module so they will be
+                // implicitly included in every further module.
+                load_module(
+                    &mut builtins.code_dir,
+                    &mut builtins.op_dir,
+                    &mut builtins.meta_predicates,
+                    &CompilationTarget::Module(clause_name!("builtins")),
+                    &loader,
+                );
+
+                for export in &loader.module_decl.exports {
+                    builtins.module_decl.exports.push(export.clone());
+                }
+
+                for arity in 10..66 {
+                    builtins
+                        .module_decl
+                        .exports
+                        .push(ModuleExport::PredicateKey((clause_name!("call"), arity)));
+                }
+            }
+
+            for (_, target_module) in self.indices.modules.iter_mut() {
+                update_call_n_indices(&loader, target_module);
+            }
+
+            self.indices.modules.insert(clause_name!("loader"), loader);
+        } else {
+            unreachable!()
+        }
+    }
+
+    pub fn new(user_input: Stream, user_output: Stream) -> Self {
+        use ref_thread_local::RefThreadLocal;
 
         let mut wam = Machine {
             machine_st: MachineState::new(),
@@ -322,16 +329,15 @@ impl Machine {
                 clause_name!("ops_and_meta_predicates.pl"),
                 lib_path.clone(),
             ),
-        ).unwrap();
+        )
+        .unwrap();
 
         bootstrapping_compile(
             Stream::from(LIBRARIES.borrow()["builtins"]),
             &mut wam,
-            ListingSource::from_file_and_path(
+            ListingSource::from_file_and_path(clause_name!("builtins.pl"), lib_path.clone()),
-                clause_name!("builtins.pl"),
+        )
-                lib_path.clone(),
+        .unwrap();
-            ),
-        ).unwrap();
 
         if let Some(builtins) = wam.indices.modules.get(&clause_name!("builtins")) {
             load_module(
@@ -350,38 +356,20 @@ impl Machine {
         bootstrapping_compile(
             Stream::from(include_str!("../loader.pl")),
             &mut wam,
-            ListingSource::from_file_and_path(
+            ListingSource::from_file_and_path(clause_name!("loader.pl"), lib_path.clone()),
-                clause_name!("loader.pl"),
+        )
-                lib_path.clone(),
+        .unwrap();
-            ),
-        ).unwrap();
 
-        if let Some(loader) = wam.indices.modules.swap_remove(&clause_name!("loader")) {
+        wam.configure_modules();
-            if let Some(builtins) = wam.indices.modules.get_mut(&clause_name!("builtins")) {
-                // Import loader's exports into the builtins module so they will be
-                // implicitly included every further module.
-                load_module(
-                    &mut builtins.code_dir,
-                    &mut builtins.op_dir,
-                    &mut builtins.meta_predicates,
-                    &CompilationTarget::Module(clause_name!("builtins")),
-                    &loader,
-                );
-
-                for export in &loader.module_decl.exports {
-                    builtins.module_decl.exports.push(export.clone());
-                }
-            }
 
+        if let Some(loader) = wam.indices.modules.get(&clause_name!("loader")) {
             load_module(
                 &mut wam.indices.code_dir,
                 &mut wam.indices.op_dir,
                 &mut wam.indices.meta_predicates,
                 &CompilationTarget::User,
-                &loader,
+                loader,
             );
-
-            wam.indices.modules.insert(clause_name!("loader"), loader);
         } else {
             unreachable!()
         }
@@ -396,25 +384,19 @@ impl Machine {
     pub fn configure_streams(&mut self) {
         self.user_input.options.alias = Some(clause_name!("user_input"));
 
-        self.indices.stream_aliases.insert(
+        self.indices
-            clause_name!("user_input"),
+            .stream_aliases
-            self.user_input.clone(),
+            .insert(clause_name!("user_input"), self.user_input.clone());
-        );
 
-        self.indices.streams.insert(
+        self.indices.streams.insert(self.user_input.clone());
-            self.user_input.clone()
-        );
 
         self.user_output.options.alias = Some(clause_name!("user_output"));
 
-        self.indices.stream_aliases.insert(
+        self.indices
-            clause_name!("user_output"),
+            .stream_aliases
-            self.user_output.clone(),
+            .insert(clause_name!("user_output"), self.user_output.clone());
-        );
 
-        self.indices.streams.insert(
+        self.indices.streams.insert(self.user_output.clone());
-            self.user_output.clone()
-        );
     }
 
     fn throw_session_error(&mut self, err: SessionError, key: PredicateKey) {
@@ -487,25 +469,33 @@ impl Machine {
             REPLCodePtr::BuiltInProperty => {
                 self.builtin_property();
             }
-            REPLCodePtr::CompilePendingPredicates => {
+            REPLCodePtr::MultifileProperty => {
-                self.compile_pending_predicates();
+                self.multifile_property();
             }
-            REPLCodePtr::UserAssertz => {
+            REPLCodePtr::DiscontiguousProperty => {
-                self.compile_user_assert(AppendOrPrepend::Append);
+                self.discontiguous_property();
             }
-            REPLCodePtr::UserAsserta => {
+            REPLCodePtr::DynamicProperty => {
-                self.compile_user_assert(AppendOrPrepend::Prepend);
+                self.dynamic_property();
             }
-            REPLCodePtr::UserRetract => {
+            REPLCodePtr::Assertz => {
-                self.retract_user_clause();
+                self.compile_assert(AppendOrPrepend::Append);
+            }
+            REPLCodePtr::Asserta => {
+                self.compile_assert(AppendOrPrepend::Prepend);
+            }
+            REPLCodePtr::Retract => {
+                self.retract_clause();
+            }
+            REPLCodePtr::AbolishClause => {
+                self.abolish_clause();
             }
         }
 
         self.machine_st.p = CodePtr::Local(p);
     }
 
-    pub(super)
+    pub(super) fn run_query(&mut self) {
-    fn run_query(&mut self) {
         while !self.machine_st.p.is_halt() {
             self.machine_st.query_stepper(
                 &mut self.indices,
@@ -523,23 +513,6 @@ impl Machine {
                         self.machine_st.backtrack();
                     }
                 }
-                /*
-                CodePtr::DynamicTransaction(_trans_type, _p) => {
-                    // self.code_repo.cached_query is about to be overwritten by the term expander,
-                    // so hold onto it locally and restore it after the compiler has finished.
-                    self.machine_st.fail = false;
-                    /*
-                    let cached_query = mem::replace(&mut self.code_repo.cached_query, vec![]);
-
-                    // self.dynamic_transaction(trans_type, p);
-                    self.code_repo.cached_query = cached_query;
-
-                    if let CodePtr::Local(LocalCodePtr::TopLevel(_, 0)) = self.machine_st.p {
-                        break;
-                    }
-                    */
-                }
-                */
                 _ => {
                     break;
                 }
@@ -559,26 +532,22 @@ impl MachineState {
         user_output: &mut Stream,
     ) {
         match instr {
-            &Line::Arithmetic(ref arith_instr) => {
+            &Line::Arithmetic(ref arith_instr) => self.execute_arith_instr(arith_instr),
-                self.execute_arith_instr(arith_instr)
-            }
             &Line::Choice(ref choice_instr) => {
                 self.execute_choice_instr(choice_instr, &mut policies.call_policy)
             }
             &Line::Cut(ref cut_instr) => {
                 self.execute_cut_instr(cut_instr, &mut policies.cut_policy)
             }
-            &Line::Control(ref control_instr) => {
+            &Line::Control(ref control_instr) => self.execute_ctrl_instr(
-                self.execute_ctrl_instr(
+                indices,
-                    indices,
+                code_repo,
-                    code_repo,
+                &mut policies.call_policy,
-                    &mut policies.call_policy,
+                &mut policies.cut_policy,
-                    &mut policies.cut_policy,
+                user_input,
-                    user_input,
+                user_output,
-                    user_output,
+                control_instr,
-                    control_instr,
+            ),
-                )
-            }
             &Line::Fact(ref fact_instr) => {
                 self.execute_fact_instr(&fact_instr);
                 self.p += 1;
@@ -620,44 +589,23 @@ impl MachineState {
     }
 
     fn backtrack(&mut self) {
-        // if self.b > 0 {
         let b = self.b;
 
         self.b0 = self.stack.index_or_frame(b).prelude.b0;
         self.p = CodePtr::Local(self.stack.index_or_frame(b).prelude.bp);
 
-        /*
-        if let CodePtr::Local(LocalCodePtr::TopLevel(_, p)) = self.p {
-            self.fail = p == 0;
-        } else {
-        */
         self.fail = false;
-        // }
-        /*} else {
-            self.p = CodePtr::Local(LocalCodePtr::TopLevel(0, 0));
-        }*/
     }
 
     fn check_machine_index(&mut self, code_repo: &CodeRepo) -> bool {
         match self.p {
-            CodePtr::Local(LocalCodePtr::DirEntry(p)) |
+            CodePtr::Local(LocalCodePtr::DirEntry(p))
-            CodePtr::Local(LocalCodePtr::IndexingBuf(p, ..))
+            | CodePtr::Local(LocalCodePtr::IndexingBuf(p, ..))
-                if p < code_repo.code.len() => {
+                if p < code_repo.code.len() => {}
-                }
             CodePtr::Local(LocalCodePtr::Halt) | CodePtr::REPL(..) => {
                 return false;
             }
-            /*
+            _ => {}
-            CodePtr::DynamicTransaction(..) => {
-                // prevent use of dynamic transactions from
-                // succeeding in expansions. self.fail will be toggled
-                // back to false later.
-                self.fail = true;
-                return false;
-            }
-            */
-            _ => {
-            }
         }
 
         true
@@ -721,13 +669,7 @@ impl MachineState {
         user_output: &mut Stream,
     ) {
         loop {
-            self.execute_instr(
+            self.execute_instr(indices, policies, code_repo, user_input, user_output);
-                indices,
-                policies,
-                code_repo,
-                user_input,
-                user_output,
-            );
 
             if self.fail {
                 self.backtrack();

src/machine/preprocessor.rs

@@ -1,13 +1,14 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
-use crate::prolog_parser_rebis::tabled_rc::*;
+use prolog_parser::tabled_rc::*;
+use prolog_parser::{atom, clause_name, rc_atom};
 
 use crate::forms::*;
 use crate::iterators::*;
-use crate::machine::*;
 use crate::machine::load_state::*;
 use crate::machine::machine_errors::*;
+use crate::machine::*;
 
-use crate::indexmap::IndexSet;
+use indexmap::IndexSet;
 
 use std::cell::Cell;
 use std::collections::VecDeque;
@@ -85,28 +86,25 @@ fn setup_op_decl(
     to_op_decl(prec, spec.as_str(), name)
 }
 
-fn setup_predicate_indicator(term: &mut Term) -> Result<PredicateKey, CompilationError>
+fn setup_predicate_indicator(term: &mut Term) -> Result<PredicateKey, CompilationError> {
-{
     match term {
         Term::Clause(_, ref slash, ref mut terms, Some(_))
             if (slash.as_str() == "/" || slash.as_str() == "//") && terms.len() == 2 =>
         {
             let arity = *terms.pop().unwrap();
-            let name  = *terms.pop().unwrap();
+            let name = *terms.pop().unwrap();
 
             let arity = arity
-                .to_constant()
+                .into_constant()
-                .and_then(|c| {
+                .and_then(|c| match c {
-                    match c {
+                    Constant::Integer(n) => n.to_usize(),
-                        Constant::Integer(n) => n.to_usize(),
+                    Constant::Fixnum(n) => usize::try_from(n).ok(),
-                        Constant::Fixnum(n) => usize::try_from(n).ok(),
+                    _ => None,
-                        _ => None
-                    }
                 })
                 .ok_or(CompilationError::InvalidModuleExport)?;
 
-            let name  = name
+            let name = name
-                .to_constant()
+                .into_constant()
                 .and_then(|c| c.to_atom())
                 .ok_or(CompilationError::InvalidModuleExport)?;
 
@@ -116,9 +114,7 @@ fn setup_predicate_indicator(term: &mut Term) -> Result<PredicateKey, Compilatio
                 Ok((name, arity + 2))
             }
         }
-        _ => {
+        _ => Err(CompilationError::InvalidModuleExport),
-            Err(CompilationError::InvalidModuleExport)
-        }
     }
 }
 
@@ -155,10 +151,7 @@ fn setup_module_export(
         .or_else(|_| {
             if let Term::Clause(_, name, terms, _) = term {
                 if terms.len() == 3 && name.as_str() == "op" {
-                    Ok(ModuleExport::OpDecl(setup_op_decl(
+                    Ok(ModuleExport::OpDecl(setup_op_decl(terms, atom_tbl)?))
-                        terms,
-                        atom_tbl
-                    )?))
                 } else {
                     Err(CompilationError::InvalidModuleDecl)
                 }
@@ -168,8 +161,7 @@ fn setup_module_export(
         })
 }
 
-pub(super)
+pub(super) fn setup_module_export_list(
-fn setup_module_export_list(
     mut export_list: Term,
     atom_tbl: TabledData<Atom>,
 ) -> Result<Vec<ModuleExport>, CompilationError> {
@@ -182,7 +174,7 @@ fn setup_module_export_list(
         export_list = *t2;
     }
 
-    if export_list.to_constant() != Some(Constant::EmptyList) {
+    if export_list.into_constant() != Some(Constant::EmptyList) {
         Err(CompilationError::InvalidModuleDecl)
     } else {
         Ok(exports)
@@ -197,7 +189,7 @@ fn setup_module_decl(
     let name = terms
         .pop()
         .unwrap()
-        .to_constant()
+        .into_constant()
         .and_then(|c| c.to_atom())
         .ok_or(CompilationError::InvalidModuleDecl)?;
 
@@ -213,13 +205,12 @@ fn setup_use_module_decl(mut terms: Vec<Box<Term>>) -> Result<ModuleSource, Comp
             terms
                 .pop()
                 .unwrap()
-                .to_constant()
+                .into_constant()
                 .and_then(|c| c.to_atom())
                 .map(|c| ModuleSource::Library(c))
                 .ok_or(CompilationError::InvalidUseModuleDecl)
         }
-        Term::Constant(_, Constant::Atom(ref name, _)) =>
+        Term::Constant(_, Constant::Atom(ref name, _)) => Ok(ModuleSource::File(name.clone())),
-            Ok(ModuleSource::File(name.clone())),
         _ => Err(CompilationError::InvalidUseModuleDecl),
     }
 }
@@ -266,17 +257,13 @@ fn setup_qualified_import(
             terms
                 .pop()
                 .unwrap()
-                .to_constant()
+                .into_constant()
                 .and_then(|c| c.to_atom())
                 .map(|c| ModuleSource::Library(c))
                 .ok_or(CompilationError::InvalidUseModuleDecl)
         }
-        Term::Constant(_, Constant::Atom(ref name, _)) => {
+        Term::Constant(_, Constant::Atom(ref name, _)) => Ok(ModuleSource::File(name.clone())),
-            Ok(ModuleSource::File(name.clone()))
+        _ => Err(CompilationError::InvalidUseModuleDecl),
-        }
-        _ => {
-            Err(CompilationError::InvalidUseModuleDecl)
-        }
     }?;
 
     let mut exports = IndexSet::new();
@@ -286,7 +273,7 @@ fn setup_qualified_import(
         export_list = *t2;
     }
 
-    if export_list.to_constant() != Some(Constant::EmptyList) {
+    if export_list.into_constant() != Some(Constant::EmptyList) {
         Err(CompilationError::InvalidModuleDecl)
     } else {
         Ok((module_src, exports))
@@ -334,8 +321,7 @@ fn setup_qualified_import(
 fn setup_meta_predicate<'a>(
     mut terms: Vec<Box<Term>>,
     load_state: &LoadState<'a>,
-) -> Result<(ClauseName, ClauseName, Vec<MetaSpec>), CompilationError>
+) -> Result<(ClauseName, ClauseName, Vec<MetaSpec>), CompilationError> {
-{
     fn get_name_and_meta_specs(
         name: ClauseName,
         terms: &mut [Box<Term>],
@@ -345,26 +331,23 @@ fn setup_meta_predicate<'a>(
         for meta_spec in terms.into_iter() {
             match &**meta_spec {
                 Term::Constant(_, Constant::Atom(meta_spec, _)) => {
-                    let meta_spec =
+                    let meta_spec = match meta_spec.as_str() {
-                        match meta_spec.as_str() {
+                        "+" => MetaSpec::Plus,
-                            "+" => MetaSpec::Plus,
+                        "-" => MetaSpec::Minus,
-                            "-" => MetaSpec::Minus,
+                        "?" => MetaSpec::Either,
-                            "?" => MetaSpec::Either,
+                        _ => return Err(CompilationError::InvalidMetaPredicateDecl),
-                            _   => return Err(CompilationError::InvalidMetaPredicateDecl),
+                    };
-                        };
 
                     meta_specs.push(meta_spec);
                 }
-                Term::Constant(_, Constant::Fixnum(n)) => {
+                Term::Constant(_, Constant::Fixnum(n)) => match usize::try_from(*n) {
-                    match usize::try_from(*n) {
+                    Ok(n) if n <= MAX_ARITY => {
-                        Ok(n) if n <= MAX_ARITY => {
+                        meta_specs.push(MetaSpec::RequiresExpansionWithArgument(n));
-                            meta_specs.push(MetaSpec::RequiresExpansionWithArgument(n));
-                        }
-                        _ => {
-                            return Err(CompilationError::InvalidMetaPredicateDecl);
-                        }
                     }
-                }
+                    _ => {
+                        return Err(CompilationError::InvalidMetaPredicateDecl);
+                    }
+                },
                 _ => {
                     return Err(CompilationError::InvalidMetaPredicateDecl);
                 }
@@ -375,42 +358,35 @@ fn setup_meta_predicate<'a>(
     }
 
     match *terms.pop().unwrap() {
-        Term::Clause(_, name, mut terms, _)
+        Term::Clause(_, name, mut terms, _) if name.as_str() == ":" && terms.len() == 2 => {
-            if name.as_str() == ":" && terms.len() == 2 => {
+            let spec = *terms.pop().unwrap();
-                let spec = *terms.pop().unwrap();
+            let module_name = *terms.pop().unwrap();
-                let module_name = *terms.pop().unwrap();
 
-                match module_name {
+            match module_name {
-                    Term::Constant(_, Constant::Atom(module_name, _)) => {
+                Term::Constant(_, Constant::Atom(module_name, _)) => match spec {
-                        match spec {
+                    Term::Clause(_, name, mut terms, _) => {
-                            Term::Clause(_, name, mut terms, _) => {
+                        let (name, meta_specs) = get_name_and_meta_specs(name, &mut terms)?;
-                                let (name, meta_specs) =
-                                    get_name_and_meta_specs(name, &mut terms)?;
 
-                                Ok((module_name, name, meta_specs))
+                        Ok((module_name, name, meta_specs))
-                            }
-                            _ => {
-                                Err(CompilationError::InvalidMetaPredicateDecl)
-                            }
-                        }
                     }
-                    _ => {
+                    _ => Err(CompilationError::InvalidMetaPredicateDecl),
-                        Err(CompilationError::InvalidMetaPredicateDecl)
+                },
-                    }
+                _ => Err(CompilationError::InvalidMetaPredicateDecl),
-                }
             }
+        }
         Term::Clause(_, name, mut terms, _) => {
             let (name, meta_specs) = get_name_and_meta_specs(name, &mut terms)?;
-            Ok((load_state.module_name(), name, meta_specs))
+            Ok((
-        }
+                load_state.compilation_target.module_name(),
-        _ => {
+                name,
-            Err(CompilationError::InvalidMetaPredicateDecl)
+                meta_specs,
+            ))
         }
+        _ => Err(CompilationError::InvalidMetaPredicateDecl),
     }
 }
 
-fn merge_clauses(tls: &mut VecDeque<TopLevel>) -> Result<TopLevel, CompilationError>
+fn merge_clauses(tls: &mut VecDeque<TopLevel>) -> Result<TopLevel, CompilationError> {
-{
     let mut clauses = vec![];
 
     while let Some(tl) = tls.pop_front() {
@@ -432,9 +408,7 @@ fn merge_clauses(tls: &mut VecDeque<TopLevel>) -> Result<TopLevel, CompilationEr
                 let clause = PredicateClause::Rule(rule);
                 clauses.push(clause);
             }
-            TopLevel::Predicate(predicate) => {
+            TopLevel::Predicate(predicate) => clauses.extend(predicate.into_iter()),
-                clauses.extend(predicate.into_iter())
-            }
             _ => {
                 tls.push_front(tl);
                 break;
@@ -506,8 +480,8 @@ fn check_for_internal_if_then(terms: &mut Vec<Term>) {
 
         conq_terms.push_front(Term::Constant(
             Cell::default(),
-            Constant::Atom(clause_name!("blocked_!"), None))
+            Constant::Atom(clause_name!("blocked_!"), None),
-        );
+        ));
 
         while let Some(term) = pre_cut_terms.pop_back() {
             conq_terms.push_front(term);
@@ -531,38 +505,29 @@ fn setup_declaration<'a>(
     let atom_tbl = load_state.wam.machine_st.atom_tbl.clone();
 
     match term {
-        Term::Clause(_, name, mut terms, _) =>
+        Term::Clause(_, name, mut terms, _) => match (name.as_str(), terms.len()) {
-            match (name.as_str(), terms.len()) {
+            ("dynamic", 1) => {
-                ("dynamic", 1) => {
+                let (name, arity) = setup_predicate_indicator(&mut *terms.pop().unwrap())?;
-		            let (name, arity) = setup_predicate_indicator(&mut *terms.pop().unwrap())?;
+                Ok(Declaration::Dynamic(name, arity))
-		            Ok(Declaration::Dynamic(name, arity))
+            }
-		        }
+            ("module", 2) => Ok(Declaration::Module(setup_module_decl(terms, atom_tbl)?)),
-                ("module", 2) =>
+            ("op", 3) => Ok(Declaration::Op(setup_op_decl(terms, atom_tbl)?)),
-                    Ok(Declaration::Module(setup_module_decl(terms, atom_tbl)?)),
+            ("non_counted_backtracking", 1) => {
-                ("op", 3) =>
+                let (name, arity) = setup_predicate_indicator(&mut *terms.pop().unwrap())?;
-                    Ok(Declaration::Op(setup_op_decl(terms, atom_tbl)?)),
+                Ok(Declaration::NonCountedBacktracking(name, arity))
-                ("non_counted_backtracking", 1) => {
+            }
-                    let (name, arity) = setup_predicate_indicator(&mut *terms.pop().unwrap())?;
+            ("use_module", 1) => Ok(Declaration::UseModule(setup_use_module_decl(terms)?)),
-                    Ok(Declaration::NonCountedBacktracking(name, arity))
+            ("use_module", 2) => {
-                }
+                let (name, exports) = setup_qualified_import(terms, atom_tbl)?;
-                ("use_module", 1) => {
+                Ok(Declaration::UseQualifiedModule(name, exports))
-                    Ok(Declaration::UseModule(setup_use_module_decl(terms)?))
+            }
-                }
+            ("meta_predicate", 1) => {
-                ("use_module", 2) => {
+                let (module_name, name, meta_specs) = setup_meta_predicate(terms, load_state)?;
-                    let (name, exports) = setup_qualified_import(terms, atom_tbl)?;
+                Ok(Declaration::MetaPredicate(module_name, name, meta_specs))
-                    Ok(Declaration::UseQualifiedModule(name, exports))
+            }
-                }
+            _ => Err(CompilationError::InconsistentEntry),
-                ("meta_predicate", 1) => {
+        },
-                    let (module_name, name, meta_specs) = setup_meta_predicate(terms, load_state)?;
+        _ => Err(CompilationError::InconsistentEntry),
-                    Ok(Declaration::MetaPredicate(module_name, name, meta_specs))
-                }
-                _ => {
-                    Err(CompilationError::InconsistentEntry)
-                }
-            },
-        _ => {
-            Err(CompilationError::InconsistentEntry)
-        }
     }
 }
 
@@ -596,8 +561,7 @@ pub(crate) struct Preprocessor {
 }
 
 impl Preprocessor {
-    pub(super)
+    pub(super) fn new(flags: MachineFlags) -> Self {
-    fn new(flags: MachineFlags) -> Self {
         Preprocessor {
             flags,
             queue: VecDeque::new(),
@@ -606,12 +570,8 @@ impl Preprocessor {
 
     fn setup_fact(&mut self, term: Term) -> Result<Term, CompilationError> {
         match term {
-            Term::Clause(..) | Term::Constant(_, Constant::Atom(..)) => {
+            Term::Clause(..) | Term::Constant(_, Constant::Atom(..)) => Ok(term),
-                Ok(term)
+            _ => Err(CompilationError::InadmissibleFact),
-            }
-            _ => {
-                Err(CompilationError::InadmissibleFact)
-            }
         }
     }
 
@@ -712,109 +672,97 @@ impl Preprocessor {
                     Ok(clause_to_query_term(load_state, name, vec![], fixity))
                 }
             }
-            Term::Constant(_, Constant::Char('!')) => {
+            Term::Constant(_, Constant::Char('!')) => Ok(QueryTerm::BlockedCut),
-                Ok(QueryTerm::BlockedCut)
-            }
             Term::Var(_, ref v) if v.as_str() == "!" => {
                 Ok(QueryTerm::UnblockedCut(Cell::default()))
             }
-            Term::Clause(r, name, mut terms, fixity) => {
+            Term::Clause(r, name, mut terms, fixity) => match (name.as_str(), terms.len()) {
-                match (name.as_str(), terms.len()) {
+                (";", 2) => {
-                    (";", 2) => {
+                    let term = Term::Clause(r, name.clone(), terms, fixity);
-                        let term = Term::Clause(r, name.clone(), terms, fixity);
 
-                        let (stub, clauses) = self.fabricate_disjunct(term);
+                    let (stub, clauses) = self.fabricate_disjunct(term);
-                        self.queue.push_back(clauses);
+                    self.queue.push_back(clauses);
 
-                        Ok(QueryTerm::Jump(stub))
+                    Ok(QueryTerm::Jump(stub))
-                    }
+                }
-                    ("->", 2) => {
+                ("->", 2) => {
-                        let conq = *terms.pop().unwrap();
+                    let conq = *terms.pop().unwrap();
-                        let prec = *terms.pop().unwrap();
+                    let prec = *terms.pop().unwrap();
 
-                        let (stub, clauses) = self.fabricate_if_then(prec, conq);
+                    let (stub, clauses) = self.fabricate_if_then(prec, conq);
-                        self.queue.push_back(clauses);
+                    self.queue.push_back(clauses);
 
-                        Ok(QueryTerm::Jump(stub))
+                    Ok(QueryTerm::Jump(stub))
-                    }
+                }
-                    ("\\+", 1) => {
+                ("\\+", 1) => {
-                        terms.push(Box::new(Term::Constant(
+                    terms.push(Box::new(Term::Constant(
-                            Cell::default(),
+                        Cell::default(),
-                            Constant::Atom(clause_name!("$fail"), None)
+                        Constant::Atom(clause_name!("$fail"), None),
-                        )));
+                    )));
 
-                        let conq = Term::Constant(
+                    let conq =
-                            Cell::default(),
+                        Term::Constant(Cell::default(), Constant::Atom(clause_name!("true"), None));
-                            Constant::Atom(clause_name!("true"), None)
-                        );
 
-                        let prec = Term::Clause(Cell::default(), clause_name!("->"), terms, None);
+                    let prec = Term::Clause(Cell::default(), clause_name!("->"), terms, None);
-                        let terms = vec![Box::new(prec), Box::new(conq)];
+                    let terms = vec![Box::new(prec), Box::new(conq)];
 
-                        let term = Term::Clause(Cell::default(), clause_name!(";"), terms, None);
+                    let term = Term::Clause(Cell::default(), clause_name!(";"), terms, None);
-                        let (stub, clauses) = self.fabricate_disjunct(term);
+                    let (stub, clauses) = self.fabricate_disjunct(term);
 
-                        debug_assert!(clauses.len() > 0);
+                    debug_assert!(clauses.len() > 0);
-                        self.queue.push_back(clauses);
+                    self.queue.push_back(clauses);
 
-                        Ok(QueryTerm::Jump(stub))
+                    Ok(QueryTerm::Jump(stub))
-                    }
+                }
-                    ("$get_level", 1) => {
+                ("$get_level", 1) => {
-                        if let Term::Var(_, ref var) = *terms[0] {
+                    if let Term::Var(_, ref var) = *terms[0] {
-                            Ok(QueryTerm::GetLevelAndUnify(Cell::default(), var.clone()))
+                        Ok(QueryTerm::GetLevelAndUnify(Cell::default(), var.clone()))
-                        } else {
+                    } else {
-                            Err(CompilationError::InadmissibleQueryTerm)
+                        Err(CompilationError::InadmissibleQueryTerm)
-                        }
-                    }
-                    (":", 2) => {
-                        let predicate_name = *terms.pop().unwrap();
-                        let module_name = *terms.pop().unwrap();
-
-                        match (module_name, predicate_name) {
-                            (Term::Constant(_, Constant::Atom(module_name, _)),
-                             Term::Constant(_, Constant::Atom(predicate_name, fixity))) => {
-                                Ok(qualified_clause_to_query_term(
-                                    load_state,
-                                    module_name,
-                                    predicate_name,
-                                    vec![],
-                                    fixity,
-                                ))
-                            }
-                            (Term::Constant(_, Constant::Atom(module_name, _)),
-                             Term::Clause(_, name, terms, fixity)) => {
-                                Ok(qualified_clause_to_query_term(
-                                    load_state,
-                                    module_name,
-                                    name,
-                                    terms,
-                                    fixity,
-                                ))
-                            }
-                            (module_name, predicate_name) => {
-                                terms.push(Box::new(module_name));
-                                terms.push(Box::new(predicate_name));
-
-                                Ok(clause_to_query_term(load_state, name, terms, fixity))
-                            }
-                        }
-                    }
-                    _ => {
-                        Ok(clause_to_query_term(load_state, name, terms, fixity))
                     }
                 }
-            }
+                (":", 2) => {
-            Term::Var(..) => {
+                    let predicate_name = *terms.pop().unwrap();
-                Ok(QueryTerm::Clause(
+                    let module_name = *terms.pop().unwrap();
-                    Cell::default(),
+
-                    ClauseType::CallN,
+                    match (module_name, predicate_name) {
-                    vec![Box::new(term)],
+                        (
-                    false,
+                            Term::Constant(_, Constant::Atom(module_name, _)),
-                ))
+                            Term::Constant(_, Constant::Atom(predicate_name, fixity)),
-            }
+                        ) => Ok(qualified_clause_to_query_term(
-            _ => {
+                            load_state,
-                Err(CompilationError::InadmissibleQueryTerm)
+                            module_name,
-            }
+                            predicate_name,
+                            vec![],
+                            fixity,
+                        )),
+                        (
+                            Term::Constant(_, Constant::Atom(module_name, _)),
+                            Term::Clause(_, name, terms, fixity),
+                        ) => Ok(qualified_clause_to_query_term(
+                            load_state,
+                            module_name,
+                            name,
+                            terms,
+                            fixity,
+                        )),
+                        (module_name, predicate_name) => {
+                            terms.push(Box::new(module_name));
+                            terms.push(Box::new(predicate_name));
+
+                            Ok(clause_to_query_term(load_state, name, terms, fixity))
+                        }
+                    }
+                }
+                _ => Ok(clause_to_query_term(load_state, name, terms, fixity)),
+            },
+            Term::Var(..) => Ok(QueryTerm::Clause(
+                Cell::default(),
+                ClauseType::CallN,
+                vec![Box::new(term)],
+                false,
+            )),
+            _ => Err(CompilationError::InadmissibleQueryTerm),
         }
     }
 
@@ -835,9 +783,7 @@ impl Preprocessor {
                     self.to_query_term(load_state, Term::Clause(r, name, subterms, fixity))
                 }
             }
-            _ => {
+            _ => self.to_query_term(load_state, term),
-                self.to_query_term(load_state, term)
-            }
         }
     }
 
@@ -884,30 +830,23 @@ impl Preprocessor {
         mut terms: Vec<Box<Term>>,
         cut_context: CutContext,
     ) -> Result<Rule, CompilationError> {
-        let post_head_terms: Vec<_> = terms.drain(1 ..).collect();
+        let post_head_terms: Vec<_> = terms.drain(1..).collect();
 
-        let mut query_terms =
+        let mut query_terms = self.setup_query(load_state, post_head_terms, cut_context)?;
-            self.setup_query(load_state, post_head_terms, cut_context)?;
 
-        let clauses = query_terms.drain(1 ..).collect();
+        let clauses = query_terms.drain(1..).collect();
         let qt = query_terms.pop().unwrap();
 
         match *terms.pop().unwrap() {
-            Term::Clause(_, name, terms, _) => {
+            Term::Clause(_, name, terms, _) => Ok(Rule {
-                Ok(Rule {
+                head: (name, terms, qt),
-                    head: (name, terms, qt),
+                clauses,
-                    clauses,
+            }),
-                })
+            Term::Constant(_, Constant::Atom(name, _)) => Ok(Rule {
-            }
+                head: (name, vec![], qt),
-            Term::Constant(_, Constant::Atom(name, _)) => {
+                clauses,
-                Ok(Rule {
+            }),
-                    head: (name, vec![], qt),
+            _ => Err(CompilationError::InvalidRuleHead),
-                    clauses,
-                })
-            }
-            _ => {
-                Err(CompilationError::InvalidRuleHead)
-            }
         }
     }
 
@@ -917,11 +856,14 @@ impl Preprocessor {
         terms: Vec<Box<Term>>,
         cut_context: CutContext,
     ) -> Result<TopLevel, CompilationError> {
-        Ok(TopLevel::Query(self.setup_query(load_state, terms, cut_context)?))
+        Ok(TopLevel::Query(self.setup_query(
+            load_state,
+            terms,
+            cut_context,
+        )?))
     }
 
-    pub(super)
+    pub(super) fn try_term_to_tl<'a>(
-    fn try_term_to_tl<'a>(
         &mut self,
         load_state: &mut LoadState<'a>,
         term: Term,
@@ -944,9 +886,7 @@ impl Preprocessor {
                     Ok(TopLevel::Fact(self.setup_fact(term)?))
                 }
             }
-            term => {
+            term => Ok(TopLevel::Fact(self.setup_fact(term)?)),
-                Ok(TopLevel::Fact(self.setup_fact(term)?))
-            }
         }
     }
 
@@ -965,21 +905,18 @@ impl Preprocessor {
         Ok(results)
     }
 
-    pub(super)
+    pub(super) fn parse_queue<'a>(
-    fn parse_queue<'a>(
         &mut self,
         load_state: &mut LoadState<'a>,
     ) -> Result<VecDeque<TopLevel>, CompilationError> {
         let mut queue = VecDeque::new();
 
         while let Some(terms) = self.queue.pop_front() {
-            let clauses = merge_clauses(
+            let clauses = merge_clauses(&mut self.try_terms_to_tls(
-                &mut self.try_terms_to_tls(
+                load_state,
-                    load_state,
+                terms,
-                    terms,
+                CutContext::HasCutVariable,
-                    CutContext::HasCutVariable,
+            )?)?;
-                )?
-            )?;
 
             queue.push_back(clauses);
         }

src/machine/term_stream.rs

@@ -1,16 +1,16 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
-use crate::prolog_parser_rebis::parser::*;
+use prolog_parser::parser::*;
 
-use crate::machine::*;
 use crate::machine::machine_errors::CompilationError;
 use crate::machine::preprocessor::*;
+use crate::machine::*;
 
 use indexmap::IndexSet;
 
 use std::collections::VecDeque;
 use std::fmt;
 
-pub(crate) trait TermStream : Sized {
+pub(crate) trait TermStream: Sized {
     type Evacuable;
 
     fn next(&mut self, op_dir: &CompositeOpDir) -> Result<Term, CompilationError>;
@@ -27,15 +27,17 @@ pub(super) struct BootstrappingTermStream<'a> {
 
 impl<'a> BootstrappingTermStream<'a> {
     #[inline]
-    pub(super)
+    pub(super) fn from_prolog_stream(
-    fn from_prolog_stream(
         stream: &'a mut PrologStream,
         atom_tbl: TabledData<Atom>,
         flags: MachineFlags,
         listing_src: ListingSource,
     ) -> Self {
         let parser = Parser::new(stream, atom_tbl, flags);
-        Self { parser, listing_src }
+        Self {
+            parser,
+            listing_src,
+        }
     }
 }
 
@@ -45,13 +47,14 @@ impl<'a> TermStream for BootstrappingTermStream<'a> {
     #[inline]
     fn next(&mut self, op_dir: &CompositeOpDir) -> Result<Term, CompilationError> {
         self.parser.reset();
-        self.parser.read_term(op_dir)
+        self.parser
+            .read_term(op_dir)
             .map_err(CompilationError::from)
     }
 
     #[inline]
     fn eof(&mut self) -> Result<bool, CompilationError> {
-	    self.parser.devour_whitespace()?; // eliminate dangling comments before checking for EOF.
+        self.parser.devour_whitespace()?; // eliminate dangling comments before checking for EOF.
         Ok(self.parser.eof()?)
     }
 
@@ -65,9 +68,10 @@ impl<'a> TermStream for BootstrappingTermStream<'a> {
             loader.compile_and_submit()?;
         }
 
-        loader.load_state.retraction_info.reset(
+        loader
-            loader.load_state.wam.code_repo.code.len(),
+            .load_state
-        );
+            .retraction_info
+            .reset(loader.load_state.wam.code_repo.code.len());
 
         loader.load_state.remove_module_op_exports();
 
@@ -82,8 +86,7 @@ pub struct LiveTermStream {
 
 impl LiveTermStream {
     #[inline]
-    pub(super)
+    pub(super) fn new(listing_src: ListingSource) -> Self {
-    fn new(listing_src: ListingSource) -> Self {
         Self {
             term_queue: VecDeque::new(),
             listing_src,
@@ -109,8 +112,7 @@ impl fmt::Debug for LoadStatePayload {
 }
 
 impl LoadStatePayload {
-    pub(super)
+    pub(super) fn new(wam: &Machine) -> Self {
-    fn new(wam: &Machine) -> Self {
         Self {
             term_stream: LiveTermStream::new(ListingSource::User),
             compilation_target: CompilationTarget::default(),

src/main.rs

@@ -1,43 +1,14 @@
-extern crate blake2;
-extern crate chrono;
-extern crate cpu_time;
-extern crate crossterm;
-extern crate divrem;
-#[macro_use]
-extern crate downcast;
-extern crate git_version;
-extern crate hostname;
-extern crate indexmap;
-#[macro_use]
-extern crate lazy_static;
-extern crate libc;
-extern crate native_tls;
-extern crate nix;
-extern crate openssl;
-extern crate ordered_float;
-#[macro_use]
-extern crate prolog_parser_rebis;
-#[macro_use]
-extern crate ref_thread_local;
-extern crate ring;
-extern crate ripemd160;
-#[cfg(feature = "rug")]
-extern crate rug;
 #[cfg(feature = "num-rug-adapter")]
-extern crate num_rug_adapter as rug;
+use num_rug_adapter as rug;
-extern crate rustyline;
+#[cfg(feature = "rug")]
-extern crate sha3;
+use rug;
-extern crate unicode_reader;
-
-use crate::nix::sys::signal;
 
 #[macro_use]
 mod macros;
 mod allocator;
 mod arithmetic;
-mod machine;
-mod codegen;
 mod clause_types;
+mod codegen;
 mod debray_allocator;
 mod fixtures;
 mod forms;
@@ -46,17 +17,19 @@ mod heap_print;
 mod indexing;
 mod instructions;
 mod iterators;
+mod machine;
 mod read;
 mod targets;
 mod write;
 
-use machine::*;
 use machine::streams::*;
+use machine::*;
 use read::*;
 
+use nix::sys::signal;
 use std::sync::atomic::Ordering;
 
-extern fn handle_sigint(signal: libc::c_int) {
+extern "C" fn handle_sigint(signal: libc::c_int) {
     let signal = signal::Signal::from_c_int(signal).unwrap();
     if signal == signal::Signal::SIGINT {
         INTERRUPT.store(true, Ordering::Relaxed);

src/read.rs

@@ -1,6 +1,6 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
-use crate::prolog_parser_rebis::parser::*;
+use prolog_parser::parser::*;
-use crate::prolog_parser_rebis::tabled_rc::TabledData;
+use prolog_parser::tabled_rc::TabledData;
 
 use crate::forms::*;
 use crate::iterators::*;
@@ -16,8 +16,8 @@ pub type PrologStream = ParsingStream<Stream>;
 
 pub mod readline {
     use crate::machine::streams::Stream;
-    use crate::rustyline::error::ReadlineError;
+    use rustyline::error::ReadlineError;
-    use crate::rustyline::{Cmd, Editor, KeyEvent};
+    use rustyline::{Cmd, Config, Editor, KeyEvent};
     use std::io::{Cursor, Error, ErrorKind, Read};
 
     static mut PROMPT: bool = false;
@@ -33,7 +33,11 @@ pub mod readline {
     #[inline]
     fn get_prompt() -> &'static str {
         unsafe {
-            if PROMPT { "?- " } else { "" }
+            if PROMPT {
+                "?- "
+            } else {
+                ""
+            }
         }
     }
 
@@ -46,7 +50,11 @@ pub mod readline {
     impl ReadlineStream {
         #[inline]
         pub fn new(pending_input: String) -> Self {
-            let mut rl = Editor::<()>::new();
+            let config = Config::builder()
+                .check_cursor_position(true)
+                .build();
+
+            let mut rl = Editor::<()>::with_config(config); //Editor::<()>::new();
             if let Some(mut path) = dirs_next::home_dir() {
                 path.push(HISTORY_FILE);
                 if path.exists() {
@@ -57,7 +65,10 @@ pub mod readline {
             }
 
             rl.bind_sequence(KeyEvent::from('\t'), Cmd::Insert(1, "\t".to_string()));
-            ReadlineStream { rl, pending_input: Cursor::new(pending_input) }
+            ReadlineStream {
+                rl,
+                pending_input: Cursor::new(pending_input),
+            }
         }
 
         #[inline]
@@ -85,12 +96,8 @@ pub mod readline {
 
                     self.pending_input.read(buf)
                 }
-                Err(ReadlineError::Eof) => {
+                Err(ReadlineError::Eof) => Ok(0),
-                    Ok(0)
+                Err(e) => Err(Error::new(ErrorKind::InvalidInput, e)),
-                }
-                Err(e) => {
-                    Err(Error::new(ErrorKind::InvalidInput, e))
-                }
             }
         }
 
@@ -117,21 +124,15 @@ pub mod readline {
                     Some(b) => {
                         return Ok(b);
                     }
-                    None => {
+                    None => match self.call_readline(&mut []) {
-                        match self.call_readline(&mut []) {
+                        Err(e) => {
-                            Err(e) => {
+                            return Err(e);
-                                return Err(e);
-                            }
-                            Ok(0) => {
-                                return Err(Error::new(
-                                    ErrorKind::UnexpectedEof,
-                                    "end of file",
-                                ));
-                            }
-                            _ => {
-                            }
                         }
-                    }
+                        Ok(0) => {
+                            return Err(Error::new(ErrorKind::UnexpectedEof, "end of file"));
+                        }
+                        _ => {}
+                    },
                 }
             }
         }
@@ -144,21 +145,15 @@ pub mod readline {
                     Some(c) => {
                         return Ok(c);
                     }
-                    None => {
+                    None => match self.call_readline(&mut []) {
-                        match self.call_readline(&mut []) {
+                        Err(e) => {
-                            Err(e) => {
+                            return Err(e);
-                                return Err(e);
-                            }
-                            Ok(0) => {
-                                return Err(Error::new(
-                                    ErrorKind::UnexpectedEof,
-                                    "end of file",
-                                ));
-                            }
-                            _ => {
-                            }
                         }
-                    }
+                        Ok(0) => {
+                            return Err(Error::new(ErrorKind::UnexpectedEof, "end of file"));
+                        }
+                        _ => {}
+                    },
                 }
             }
         }
@@ -167,12 +162,8 @@ pub mod readline {
     impl Read for ReadlineStream {
         fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
             match self.pending_input.read(buf) {
-                Ok(0) => {
+                Ok(0) => self.call_readline(buf),
-                    self.call_readline(buf)
+                result => result,
-                }
-                result => {
-                    result
-                }
             }
         }
     }
@@ -210,8 +201,7 @@ impl MachineState {
 }
 
 #[inline]
-pub(crate)
+pub(crate) fn write_term_to_heap(term: &Term, machine_st: &mut MachineState) -> TermWriteResult {
-fn write_term_to_heap(term: &Term, machine_st: &mut MachineState) -> TermWriteResult {
     let term_writer = TermWriter::new(machine_st);
     term_writer.write_term_to_heap(term)
 }
@@ -242,8 +232,7 @@ impl<'a> TermWriter<'a> {
     #[inline]
     fn modify_head_of_queue(&mut self, term: &TermRef<'a>, h: usize) {
         if let Some((arity, site_h)) = self.queue.pop_front() {
-            self.machine_st.heap[site_h] =
+            self.machine_st.heap[site_h] = HeapCellValue::Addr(self.term_as_addr(term, h));
-                HeapCellValue::Addr(self.term_as_addr(term, h));
 
             if arity > 1 {
                 self.queue.push_front((arity - 1, site_h + 1));
@@ -254,26 +243,18 @@ impl<'a> TermWriter<'a> {
     #[inline]
     fn push_stub_addr(&mut self) {
         let h = self.machine_st.heap.h();
-        self.machine_st.heap.push(HeapCellValue::Addr(Addr::HeapCell(h)));
+        self.machine_st
+            .heap
+            .push(HeapCellValue::Addr(Addr::HeapCell(h)));
     }
 
     fn term_as_addr(&mut self, term: &TermRef<'a>, h: usize) -> Addr {
         match term {
-            &TermRef::AnonVar(_) | &TermRef::Var(..) => {
+            &TermRef::AnonVar(_) | &TermRef::Var(..) => Addr::HeapCell(h),
-                Addr::HeapCell(h)
+            &TermRef::Cons(..) => Addr::HeapCell(h),
-            }
+            &TermRef::Constant(_, _, c) => self.machine_st.heap.put_constant(c.clone()),
-            &TermRef::Cons(..) => {
+            &TermRef::Clause(..) => Addr::Str(h),
-                Addr::HeapCell(h)
+            &TermRef::PartialString(..) => Addr::PStrLocation(h, 0),
-            }
-            &TermRef::Constant(_, _, c) => {
-                self.machine_st.heap.put_constant(c.clone())
-            }
-            &TermRef::Clause(..) => {
-                Addr::Str(h)
-            }
-            &TermRef::PartialString(..) => {
-                Addr::PStrLocation(h, 0)
-            }
         }
     }
 
@@ -286,7 +267,9 @@ impl<'a> TermWriter<'a> {
             match &term {
                 &TermRef::Cons(lvl, ..) => {
                     self.queue.push_back((2, h + 1));
-                    self.machine_st.heap.push(HeapCellValue::Addr(Addr::Lis(h + 1)));
+                    self.machine_st
+                        .heap
+                        .push(HeapCellValue::Addr(Addr::Lis(h + 1)));
 
                     self.push_stub_addr();
                     self.push_stub_addr();
@@ -355,13 +338,15 @@ impl<'a> TermWriter<'a> {
 
                     continue;
                 }
-                _ => {
+                _ => {}
-                }
             };
 
             self.modify_head_of_queue(&term, h);
         }
 
-        TermWriteResult { heap_loc, var_dict: self.var_dict }
+        TermWriteResult {
+            heap_loc,
+            var_dict: self.var_dict,
+        }
     }
 }

src/targets.rs

@@ -1,4 +1,4 @@
-use crate::prolog_parser_rebis::ast::*;
+use prolog_parser::ast::*;
 
 use crate::clause_types::*;
 use crate::forms::*;

src/toplevel.pl

@@ -1,9 +1,5 @@
 :- module('$toplevel', [argv/1,
-                        copy_term/3,
+                        copy_term/3]).
-                        predicate_property/2,
-                        prolog_load_context/2]).
-
-:- use_module(library(loader)).
 
 :- use_module(library(charsio)).
 :- use_module(library(iso_ext)).
@@ -18,15 +14,15 @@
 '$repl'([_|Args0]) :-
     \+ argv(_),
     (   append(Args1, ["--"|Args2], Args0) ->
-        asserta(argv(Args2)),
+        asserta('$toplevel':argv(Args2)),
         Args = Args1
-    ;   asserta(argv([])),
+    ;   asserta('$toplevel':argv([])),
         Args = Args0
     ),
     delegate_task(Args, []),
     repl.
 '$repl'(_) :-
-    (   \+ argv(_) -> asserta(argv([]))
+    (   \+ argv(_) -> asserta('$toplevel':argv([]))
     ;   true
     ),
     repl.
@@ -41,7 +37,8 @@ delegate_task([Arg0|Args], Goals0) :-
     ;   member(Arg0, ["-v", "--version"]) -> print_version
     ;   member(Arg0, ["-g", "--goal"]) -> gather_goal(g, Args, Goals0)
     ;   atom_chars(Mod, Arg0),
-        catch(use_module(Mod), E, print_exception(E))
+        catch(use_module(Mod), E, print_exception(E)),
+        nl
     ),
     delegate_task(Args, Goals0).
 
@@ -126,7 +123,7 @@ instruction_match(Term, VarList) :-
 	      (  Item == user ->
 	         catch(load(user_input), E, print_exception_with_check(E))
 	      ;
-             consult(Item)
+             submit_query_and_print_results(consult(Item), [])
 	      )
        ;
 	   catch(type_error(atom, Item, repl/0),

src/write.rs

@@ -26,14 +26,14 @@ impl fmt::Display for REPLCodePtr {
                 write!(f, "REPLCodePtr::AddGoalExpansionClause"),
             REPLCodePtr::AddTermExpansionClause =>
                 write!(f, "REPLCodePtr::AddTermExpansionClause"),
-            REPLCodePtr::BuiltInProperty =>
+            REPLCodePtr::AbolishClause =>
-                write!(f, "REPLCodePtr::BuiltInProperty"),
+                write!(f, "REPLCodePtr::AbolishClause"),
-            REPLCodePtr::UserAssertz =>
+            REPLCodePtr::Assertz =>
-                write!(f, "REPLCodePtr::UserAssertz"),
+                write!(f, "REPLCodePtr::Assertz"),
-            REPLCodePtr::UserAsserta =>
+            REPLCodePtr::Asserta =>
-                write!(f, "REPLCodePtr::UserAsserta"),
+                write!(f, "REPLCodePtr::Asserta"),
-            REPLCodePtr::UserRetract =>
+            REPLCodePtr::Retract =>
-                write!(f, "REPLCodePtr::UserRetract"),
+                write!(f, "REPLCodePtr::Retract"),
             REPLCodePtr::ClauseToEvacuable =>
                 write!(f, "REPLCodePtr::ClauseToEvacuable"),
             REPLCodePtr::ConcludeLoad =>
@@ -64,8 +64,14 @@ impl fmt::Display for REPLCodePtr {
 		        write!(f, "REPLCodePtr::UseModule"),
             REPLCodePtr::MetaPredicateProperty =>
                 write!(f, "REPLCodePtr::MetaPredicateProperty"),
-            REPLCodePtr::CompilePendingPredicates =>
+            REPLCodePtr::BuiltInProperty =>
-                write!(f, "REPLCodePtr::CompilePendingPredicates"),
+                write!(f, "REPLCodePtr::BuiltInProperty"),
+            REPLCodePtr::DynamicProperty =>
+                write!(f, "REPLCodePtr::DynamicProperty"),
+            REPLCodePtr::MultifileProperty =>
+                write!(f, "REPLCodePtr::MultifileProperty"),
+            REPLCodePtr::DiscontiguousProperty =>
+                write!(f, "REPLCodePtr::DiscontiguousProperty"),
         }
     }
 }
@@ -371,15 +377,15 @@ impl fmt::Display for SessionError {
             // &SessionError::InvalidFileName(ref filename) => {
             //     write!(f, "filename {} is invalid", filename)
             // }
-            // &SessionError::ModuleDoesNotContainExport(ref module, ref key) => {
+            &SessionError::ModuleDoesNotContainExport(ref module, ref key) => {
-            //     write!(
+                write!(
-            //         f,
+                    f,
-            //         "module {} does not contain claimed export {}/{}",
+                    "module {} does not contain claimed export {}/{}",
-            //         module,
+                    module,
-            //         key.0,
+                    key.0,
-            //         key.1,
+                    key.1,
-            //     )
+                )
-            // }
+            }
             &SessionError::OpIsInfixAndPostFix(_) => {
                 write!(f, "cannot define an op to be both postfix and infix.")
             }