split into lib and bin

* makes most pub things in src/ pub(crate) as not to expose things accidentally
  * only those things needed by src/bin/scryer-prolog.rs and tests/scryer.rs
    should be pub
* split src/main.rs into src/lib.rs and src/bin/scryer-prolog.rs
* add tests folder and run most of the files in src/tests with cargo test
  added bytes method to Stream in src/machine/streams.rs to check if stdout is as expected

build.rs

@@ -44,7 +44,7 @@ fn main() {
     libraries
         .write_all(
             b"ref_thread_local::ref_thread_local! {
-    pub static managed LIBRARIES: IndexMap<&'static str, &'static str> = {
+    pub(crate) static managed LIBRARIES: IndexMap<&'static str, &'static str> = {
         let mut m = IndexMap::new();\n",
         )
         .unwrap();

src/allocator.rs

@@ -9,7 +9,7 @@ use crate::targets::*;
 use std::cell::Cell;
 use std::rc::Rc;
 
-pub trait Allocator<'a> {
+pub(crate) trait Allocator<'a> {
     fn new() -> Self;
 
     fn mark_anon_var<Target>(&mut self, _: Level, _: GenContext, _: &mut Vec<Target>)

src/arithmetic.rs

@@ -25,11 +25,11 @@ use std::rc::Rc;
 use std::vec::Vec;
 
 #[derive(Debug)]
-pub struct ArithInstructionIterator<'a> {
+pub(crate) struct ArithInstructionIterator<'a> {
     state_stack: Vec<TermIterState<'a>>,
 }
 
-pub type ArithCont = (Code, Option<ArithmeticTerm>);
+pub(crate) type ArithCont = (Code, Option<ArithmeticTerm>);
 
 impl<'a> ArithInstructionIterator<'a> {
     fn push_subterm(&mut self, lvl: Level, term: &'a Term) {
@@ -71,7 +71,7 @@ impl<'a> ArithInstructionIterator<'a> {
 }
 
 #[derive(Debug)]
-pub enum ArithTermRef<'a> {
+pub(crate) enum ArithTermRef<'a> {
     Constant(&'a Constant),
     Op(ClauseName, usize), // name, arity.
     Var(&'a Cell<VarReg>, Rc<Var>),
@@ -113,13 +113,13 @@ impl<'a> Iterator for ArithInstructionIterator<'a> {
 }
 
 #[derive(Debug)]
-pub struct ArithmeticEvaluator<'a> {
+pub(crate) struct ArithmeticEvaluator<'a> {
     bindings: &'a AllocVarDict,
     interm: Vec<ArithmeticTerm>,
     interm_c: usize,
 }
 
-pub trait ArithmeticTermIter<'a> {
+pub(crate) trait ArithmeticTermIter<'a> {
     type Iter: Iterator<Item = Result<ArithTermRef<'a>, ArithmeticError>>;
 
     fn iter(self) -> Result<Self::Iter, ArithmeticError>;
@@ -134,7 +134,7 @@ impl<'a> ArithmeticTermIter<'a> for &'a Term {
 }
 
 impl<'a> ArithmeticEvaluator<'a> {
-    pub fn new(bindings: &'a AllocVarDict, target_int: usize) -> Self {
+    pub(crate) fn new(bindings: &'a AllocVarDict, target_int: usize) -> Self {
         ArithmeticEvaluator {
             bindings,
             interm: Vec::new(),
@@ -296,7 +296,7 @@ impl<'a> ArithmeticEvaluator<'a> {
         Ok(())
     }
 
-    pub fn eval<Iter>(&mut self, src: Iter) -> Result<ArithCont, ArithmeticError>
+    pub(crate) fn eval<Iter>(&mut self, src: Iter) -> Result<ArithCont, ArithmeticError>
     where
         Iter: ArithmeticTermIter<'a>,
     {
@@ -329,7 +329,7 @@ impl<'a> ArithmeticEvaluator<'a> {
 }
 
 // integer division rounding function -- 9.1.3.1.
-pub fn rnd_i<'a>(n: &'a Number) -> RefOrOwned<'a, Number> {
+pub(crate) fn rnd_i<'a>(n: &'a Number) -> RefOrOwned<'a, Number> {
     match n {
         &Number::Integer(_) => RefOrOwned::Borrowed(n),
         &Number::Float(OrderedFloat(f)) => RefOrOwned::Owned(Number::from(
@@ -347,7 +347,7 @@ pub fn rnd_i<'a>(n: &'a Number) -> RefOrOwned<'a, Number> {
 }
 
 // floating point rounding function -- 9.1.4.1.
-pub fn rnd_f(n: &Number) -> f64 {
+pub(crate) fn rnd_f(n: &Number) -> f64 {
     match n {
         &Number::Fixnum(n) => n as f64,
         &Number::Integer(ref n) => n.to_f64(),
@@ -357,7 +357,7 @@ pub fn rnd_f(n: &Number) -> f64 {
 }
 
 // floating point result function -- 9.1.4.2.
-pub fn result_f<Round>(n: &Number, round: Round) -> Result<f64, EvalError>
+pub(crate) fn result_f<Round>(n: &Number, round: Round) -> Result<f64, EvalError>
 where
     Round: Fn(&Number) -> f64,
 {
@@ -752,7 +752,7 @@ impl<'a> From<&'a Integer> for Number {
 }
 
 // Computes n ^ power. Ignores the sign of power.
-pub fn binary_pow(mut n: Integer, power: &Integer) -> Integer {
+pub(crate) fn binary_pow(mut n: Integer, power: &Integer) -> Integer {
     let mut power = Integer::from(power.abs_ref());
 
     if power == 0 {

src/bin/scryer-prolog.rs

@@ -0,0 +1,11 @@
+fn main() {
+    use nix::sys::signal;
+    use scryer_prolog::read::readline;
+    use scryer_prolog::*;
+
+    let handler = signal::SigHandler::Handler(handle_sigint);
+    unsafe { signal::signal(signal::Signal::SIGINT, handler) }.unwrap();
+
+    let mut wam = machine::Machine::new(readline::input_stream(), machine::Stream::stdout());
+    wam.run_top_level();
+}

src/clause_types.rs

@@ -10,7 +10,7 @@ use ref_thread_local::{ref_thread_local, RefThreadLocal};
 use std::collections::BTreeMap;
 
 #[derive(Debug, Clone, Copy, Eq, PartialEq)]
-pub enum CompareNumberQT {
+pub(crate) enum CompareNumberQT {
     GreaterThan,
     LessThan,
     GreaterThanOrEqual,
@@ -33,7 +33,7 @@ impl CompareNumberQT {
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum CompareTermQT {
+pub(crate) enum CompareTermQT {
     LessThan,
     LessThanOrEqual,
     GreaterThanOrEqual,
@@ -52,14 +52,14 @@ impl CompareTermQT {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub enum ArithmeticTerm {
+pub(crate) enum ArithmeticTerm {
     Reg(RegType),
     Interm(usize),
     Number(Number),
 }
 
 impl ArithmeticTerm {
-    pub fn interm_or(&self, interm: usize) -> usize {
+    pub(crate) fn interm_or(&self, interm: usize) -> usize {
         if let &ArithmeticTerm::Interm(interm) = self {
             interm
         } else {
@@ -69,7 +69,7 @@ impl ArithmeticTerm {
 }
 
 #[derive(Debug, Clone, Eq, PartialEq)]
-pub enum InlinedClauseType {
+pub(crate) enum InlinedClauseType {
     CompareNumber(CompareNumberQT, ArithmeticTerm, ArithmeticTerm),
     IsAtom(RegType),
     IsAtomic(RegType),
@@ -83,11 +83,11 @@ pub enum InlinedClauseType {
 }
 
 ref_thread_local! {
-    pub static managed RANDOM_STATE: RandState<'static> = RandState::new();
+    pub(crate)static managed RANDOM_STATE: RandState<'static> = RandState::new();
 }
 
 ref_thread_local! {
-    pub static managed CLAUSE_TYPE_FORMS: BTreeMap<(&'static str, usize), ClauseType> = {
+    pub(crate)static managed CLAUSE_TYPE_FORMS: BTreeMap<(&'static str, usize), ClauseType> = {
         let mut m = BTreeMap::new();
 
         let r1 = temp_v!(1);
@@ -133,7 +133,7 @@ ref_thread_local! {
 }
 
 impl InlinedClauseType {
-    pub fn name(&self) -> &'static str {
+    pub(crate) fn name(&self) -> &'static str {
         match self {
             &InlinedClauseType::CompareNumber(qt, ..) => qt.name(),
             &InlinedClauseType::IsAtom(..) => "atom",
@@ -150,7 +150,7 @@ impl InlinedClauseType {
 }
 
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
-pub enum SystemClauseType {
+pub(crate) enum SystemClauseType {
     AtomChars,
     AtomCodes,
     AtomLength,
@@ -311,7 +311,7 @@ pub enum SystemClauseType {
 }
 
 impl SystemClauseType {
-    pub fn name(&self) -> ClauseName {
+    pub(crate) fn name(&self) -> ClauseName {
         match self {
             &SystemClauseType::AtomChars => clause_name!("$atom_chars"),
             &SystemClauseType::AtomCodes => clause_name!("$atom_codes"),
@@ -596,7 +596,7 @@ impl SystemClauseType {
         }
     }
 
-    pub fn from(name: &str, arity: usize) -> Option<SystemClauseType> {
+    pub(crate) fn from(name: &str, arity: usize) -> Option<SystemClauseType> {
         match (name, arity) {
             ("$abolish_clause", 3) => Some(SystemClauseType::REPL(REPLCodePtr::AbolishClause)),
             ("$add_dynamic_predicate", 4) => {
@@ -605,9 +605,9 @@ impl SystemClauseType {
             ("$add_multifile_predicate", 4) => {
                 Some(SystemClauseType::REPL(REPLCodePtr::AddMultifilePredicate))
             }
-            ("$add_discontiguous_predicate", 4) => {
+            ("$add_discontiguous_predicate", 4) => Some(SystemClauseType::REPL(
-                Some(SystemClauseType::REPL(REPLCodePtr::AddDiscontiguousPredicate))
+                REPLCodePtr::AddDiscontiguousPredicate,
-            }
+            )),
             ("$add_goal_expansion_clause", 3) => {
                 Some(SystemClauseType::REPL(REPLCodePtr::AddGoalExpansionClause))
             }
@@ -766,18 +766,16 @@ impl SystemClauseType {
             ("$asserta", 5) => Some(SystemClauseType::REPL(REPLCodePtr::Asserta)),
             ("$assertz", 5) => Some(SystemClauseType::REPL(REPLCodePtr::Assertz)),
             ("$retract_clause", 4) => Some(SystemClauseType::REPL(REPLCodePtr::Retract)),
-            ("$is_consistent_with_term_queue", 4) => {
+            ("$is_consistent_with_term_queue", 4) => Some(SystemClauseType::REPL(
-                Some(SystemClauseType::REPL(REPLCodePtr::IsConsistentWithTermQueue))
+                REPLCodePtr::IsConsistentWithTermQueue,
-            }
+            )),
-            ("$flush_term_queue", 1) => {
+            ("$flush_term_queue", 1) => Some(SystemClauseType::REPL(REPLCodePtr::FlushTermQueue)),
-                Some(SystemClauseType::REPL(REPLCodePtr::FlushTermQueue))
-            }
             ("$remove_module_exports", 2) => {
                 Some(SystemClauseType::REPL(REPLCodePtr::RemoveModuleExports))
             }
-            ("$add_non_counted_backtracking", 3) => {
+            ("$add_non_counted_backtracking", 3) => Some(SystemClauseType::REPL(
-                Some(SystemClauseType::REPL(REPLCodePtr::AddNonCountedBacktracking))
+                REPLCodePtr::AddNonCountedBacktracking,
-            }
+            )),
             ("$variant", 2) => Some(SystemClauseType::Variant),
             ("$wam_instructions", 4) => Some(SystemClauseType::WAMInstructions),
             ("$write_term", 7) => Some(SystemClauseType::WriteTerm),
@@ -848,7 +846,7 @@ impl SystemClauseType {
 }
 
 #[derive(Debug, Clone, Eq, PartialEq)]
-pub enum BuiltInClauseType {
+pub(crate) enum BuiltInClauseType {
     AcyclicTerm,
     Arg,
     Compare,
@@ -866,7 +864,7 @@ pub enum BuiltInClauseType {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub enum ClauseType {
+pub(crate) enum ClauseType {
     BuiltIn(BuiltInClauseType),
     CallN,
     Inlined(InlinedClauseType),
@@ -876,7 +874,7 @@ pub enum ClauseType {
 }
 
 impl BuiltInClauseType {
-    pub fn name(&self) -> ClauseName {
+    pub(crate) fn name(&self) -> ClauseName {
         match self {
             &BuiltInClauseType::AcyclicTerm => clause_name!("acyclic_term"),
             &BuiltInClauseType::Arg => clause_name!("arg"),
@@ -895,7 +893,7 @@ impl BuiltInClauseType {
         }
     }
 
-    pub fn arity(&self) -> usize {
+    pub(crate) fn arity(&self) -> usize {
         match self {
             &BuiltInClauseType::AcyclicTerm => 1,
             &BuiltInClauseType::Arg => 3,
@@ -916,7 +914,7 @@ impl BuiltInClauseType {
 }
 
 impl ClauseType {
-    pub fn spec(&self) -> Option<SharedOpDesc> {
+    pub(crate) fn spec(&self) -> Option<SharedOpDesc> {
         match self {
             &ClauseType::Op(_, ref spec, _) => Some(spec.clone()),
             &ClauseType::Inlined(InlinedClauseType::CompareNumber(..))
@@ -928,7 +926,7 @@ impl ClauseType {
         }
     }
 
-    pub fn name(&self) -> ClauseName {
+    pub(crate) fn name(&self) -> ClauseName {
         match self {
             &ClauseType::BuiltIn(ref built_in) => built_in.name(),
             &ClauseType::CallN => clause_name!("$call"),
@@ -939,7 +937,7 @@ impl ClauseType {
         }
     }
 
-    pub fn from(name: ClauseName, arity: usize, spec: Option<SharedOpDesc>) -> Self {
+    pub(crate) fn from(name: ClauseName, arity: usize, spec: Option<SharedOpDesc>) -> Self {
         CLAUSE_TYPE_FORMS
             .borrow()
             .get(&(name.as_str(), arity))

src/codegen.rs

@@ -22,10 +22,10 @@ use std::collections::VecDeque;
 use std::rc::Rc;
 
 #[derive(Debug)]
-pub struct ConjunctInfo<'a> {
+pub(crate) struct ConjunctInfo<'a> {
-    pub perm_vs: VariableFixtures<'a>,
+    pub(crate) perm_vs: VariableFixtures<'a>,
-    pub num_of_chunks: usize,
+    pub(crate) num_of_chunks: usize,
-    pub has_deep_cut: bool,
+    pub(crate) has_deep_cut: bool,
 }
 
 impl<'a> ConjunctInfo<'a> {
@@ -90,7 +90,7 @@ impl<'a> ConjunctInfo<'a> {
 }
 
 #[derive(Clone, Copy, Debug)]
-pub struct CodeGenSettings {
+pub(crate) struct CodeGenSettings {
     pub global_clock_tick: Option<usize>,
     pub is_extensible: bool,
     pub non_counted_bt: bool,
@@ -98,12 +98,12 @@ pub struct CodeGenSettings {
 
 impl CodeGenSettings {
     #[inline]
-    pub fn is_dynamic(&self) -> bool {
+    pub(crate) fn is_dynamic(&self) -> bool {
         self.global_clock_tick.is_some()
     }
 
     #[inline]
-    pub fn internal_try_me_else(&self, offset: usize) -> ChoiceInstruction {
+    pub(crate) fn internal_try_me_else(&self, offset: usize) -> ChoiceInstruction {
         if let Some(global_clock_time) = self.global_clock_tick {
             ChoiceInstruction::DynamicInternalElse(
                 global_clock_time,
@@ -115,7 +115,7 @@ impl CodeGenSettings {
         }
     }
 
-    pub fn try_me_else(&self, offset: usize) -> ChoiceInstruction {
+    pub(crate) fn try_me_else(&self, offset: usize) -> ChoiceInstruction {
         if let Some(global_clock_tick) = self.global_clock_tick {
             ChoiceInstruction::DynamicElse(
                 global_clock_tick,
@@ -127,7 +127,7 @@ impl CodeGenSettings {
         }
     }
 
-    pub fn internal_retry_me_else(&self, offset: usize) -> ChoiceInstruction {
+    pub(crate) fn internal_retry_me_else(&self, offset: usize) -> ChoiceInstruction {
         if let Some(global_clock_tick) = self.global_clock_tick {
             ChoiceInstruction::DynamicInternalElse(
                 global_clock_tick,
@@ -139,7 +139,7 @@ impl CodeGenSettings {
         }
     }
 
-    pub fn retry_me_else(&self, offset: usize) -> ChoiceInstruction {
+    pub(crate) fn retry_me_else(&self, offset: usize) -> ChoiceInstruction {
         if let Some(global_clock_tick) = self.global_clock_tick {
             ChoiceInstruction::DynamicElse(
                 global_clock_tick,
@@ -153,7 +153,7 @@ impl CodeGenSettings {
         }
     }
 
-    pub fn internal_trust_me(&self) -> ChoiceInstruction {
+    pub(crate) fn internal_trust_me(&self) -> ChoiceInstruction {
         if let Some(global_clock_tick) = self.global_clock_tick {
             ChoiceInstruction::DynamicInternalElse(
                 global_clock_tick,
@@ -167,7 +167,7 @@ impl CodeGenSettings {
         }
     }
 
-    pub fn trust_me(&self) -> ChoiceInstruction {
+    pub(crate) fn trust_me(&self) -> ChoiceInstruction {
         if let Some(global_clock_tick) = self.global_clock_tick {
             ChoiceInstruction::DynamicElse(
                 global_clock_tick,
@@ -183,18 +183,18 @@ impl CodeGenSettings {
 }
 
 #[derive(Debug)]
-pub struct CodeGenerator<TermMarker> {
+pub(crate) struct CodeGenerator<TermMarker> {
     atom_tbl: TabledData<Atom>,
     marker: TermMarker,
-    pub var_count: IndexMap<Rc<Var>, usize>,
+    pub(crate) var_count: IndexMap<Rc<Var>, usize>,
     settings: CodeGenSettings,
-    pub skeleton: PredicateSkeleton,
+    pub(crate) skeleton: PredicateSkeleton,
-    pub jmp_by_locs: Vec<usize>,
+    pub(crate) jmp_by_locs: Vec<usize>,
     global_jmp_by_locs_offset: usize,
 }
 
 impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
-    pub fn new(atom_tbl: TabledData<Atom>, settings: CodeGenSettings) -> Self {
+    pub(crate) fn new(atom_tbl: TabledData<Atom>, settings: CodeGenSettings) -> Self {
         CodeGenerator {
             atom_tbl,
             marker: Allocator::new(),
@@ -837,7 +837,10 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
         }
     }
 
-    pub fn compile_rule<'b: 'a>(&mut self, rule: &'b Rule) -> Result<Code, CompilationError> {
+    pub(crate) fn compile_rule<'b: 'a>(
+        &mut self,
+        rule: &'b Rule,
+    ) -> Result<Code, CompilationError> {
         let iter = ChunkedIterator::from_rule(rule);
         let conjunct_info = self.collect_var_data(iter);
 
@@ -894,7 +897,7 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
         UnsafeVarMarker::from_safe_vars(safe_vars)
     }
 
-    pub fn compile_fact<'b: 'a>(&mut self, term: &'b Term) -> Code {
+    pub(crate) fn compile_fact<'b: 'a>(&mut self, term: &'b Term) -> Code {
         self.update_var_count(post_order_iter(term));
 
         let mut vs = VariableFixtures::new();
@@ -1119,7 +1122,7 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
         Ok(Vec::from(code))
     }
 
-    pub fn compile_predicate<'b: 'a>(
+    pub(crate) fn compile_predicate<'b: 'a>(
         &mut self,
         clauses: &'b Vec<PredicateClause>,
     ) -> Result<Code, CompilationError> {

src/debray_allocator.rs

@@ -14,7 +14,7 @@ use std::collections::BTreeSet;
 use std::rc::Rc;
 
 #[derive(Debug)]
-pub struct DebrayAllocator {
+pub(crate) struct DebrayAllocator {
     bindings: IndexMap<Rc<Var>, VarData>,
     arg_c: usize,
     temp_lb: usize,

src/fixtures.rs

@@ -14,23 +14,23 @@ use std::vec::Vec;
 
 // labeled with chunk numbers.
 #[derive(Debug)]
-pub enum VarStatus {
+pub(crate) enum VarStatus {
     Perm(usize),
     Temp(usize, TempVarData), // Perm(chunk_num) | Temp(chunk_num, _)
 }
 
-pub type OccurrenceSet = BTreeSet<(GenContext, usize)>;
+pub(crate) type OccurrenceSet = BTreeSet<(GenContext, usize)>;
 
 // Perm: 0 initially, a stack register once processed.
 // Temp: labeled with chunk_num and temp offset (unassigned if 0).
 #[derive(Debug)]
-pub enum VarData {
+pub(crate) enum VarData {
     Perm(usize),
     Temp(usize, usize, TempVarData),
 }
 
 impl VarData {
-    pub fn as_reg_type(&self) -> RegType {
+    pub(crate) fn as_reg_type(&self) -> RegType {
         match self {
             &VarData::Temp(_, r, _) => RegType::Temp(r),
             &VarData::Perm(r) => RegType::Perm(r),
@@ -39,15 +39,15 @@ impl VarData {
 }
 
 #[derive(Debug)]
-pub struct TempVarData {
+pub(crate) struct TempVarData {
-    pub last_term_arity: usize,
+    pub(crate) last_term_arity: usize,
-    pub use_set: OccurrenceSet,
+    pub(crate) use_set: OccurrenceSet,
-    pub no_use_set: BTreeSet<usize>,
+    pub(crate) no_use_set: BTreeSet<usize>,
-    pub conflict_set: BTreeSet<usize>,
+    pub(crate) conflict_set: BTreeSet<usize>,
 }
 
 impl TempVarData {
-    pub fn new(last_term_arity: usize) -> Self {
+    pub(crate) fn new(last_term_arity: usize) -> Self {
         TempVarData {
             last_term_arity: last_term_arity,
             use_set: BTreeSet::new(),
@@ -56,7 +56,7 @@ impl TempVarData {
         }
     }
 
-    pub fn uses_reg(&self, reg: usize) -> bool {
+    pub(crate) fn uses_reg(&self, reg: usize) -> bool {
         for &(_, nreg) in self.use_set.iter() {
             if reg == nreg {
                 return true;
@@ -66,7 +66,7 @@ impl TempVarData {
         return false;
     }
 
-    pub fn populate_conflict_set(&mut self) {
+    pub(crate) fn populate_conflict_set(&mut self) {
         if self.last_term_arity > 0 {
             let arity = self.last_term_arity;
             let mut conflict_set: BTreeSet<usize> = (1..arity).collect();
@@ -83,29 +83,29 @@ impl TempVarData {
 type VariableFixture<'a> = (VarStatus, Vec<&'a Cell<VarReg>>);
 
 #[derive(Debug)]
-pub struct VariableFixtures<'a> {
+pub(crate) struct VariableFixtures<'a> {
     perm_vars: IndexMap<Rc<Var>, VariableFixture<'a>>,
     last_chunk_temp_vars: IndexSet<Rc<Var>>,
 }
 
 impl<'a> VariableFixtures<'a> {
-    pub fn new() -> Self {
+    pub(crate) fn new() -> Self {
         VariableFixtures {
             perm_vars: IndexMap::new(),
             last_chunk_temp_vars: IndexSet::new(),
         }
     }
 
-    pub fn insert(&mut self, var: Rc<Var>, vs: VariableFixture<'a>) {
+    pub(crate) fn insert(&mut self, var: Rc<Var>, vs: VariableFixture<'a>) {
         self.perm_vars.insert(var, vs);
     }
 
-    pub fn insert_last_chunk_temp_var(&mut self, var: Rc<Var>) {
+    pub(crate) fn insert_last_chunk_temp_var(&mut self, var: Rc<Var>) {
         self.last_chunk_temp_vars.insert(var);
     }
 
     // computes no_use and conflict sets for all temp vars.
-    pub fn populate_restricting_sets(&mut self) {
+    pub(crate) fn populate_restricting_sets(&mut self) {
         // three stages:
         // 1. move the use sets of each variable to a local IndexMap, use_set
         // (iterate mutably, swap mutable refs).
@@ -170,7 +170,7 @@ impl<'a> VariableFixtures<'a> {
         };
     }
 
-    pub fn vars_above_threshold(&self, index: usize) -> usize {
+    pub(crate) fn vars_above_threshold(&self, index: usize) -> usize {
         let mut var_count = 0;
 
         for &(ref var_status, _) in self.values() {
@@ -184,7 +184,7 @@ impl<'a> VariableFixtures<'a> {
         var_count
     }
 
-    pub fn mark_vars_in_chunk<I>(&mut self, iter: I, lt_arity: usize, term_loc: GenContext)
+    pub(crate) fn mark_vars_in_chunk<I>(&mut self, iter: I, lt_arity: usize, term_loc: GenContext)
     where
         I: Iterator<Item = TermRef<'a>>,
     {
@@ -218,7 +218,7 @@ impl<'a> VariableFixtures<'a> {
         }
     }
 
-    pub fn into_iter(self) -> indexmap::map::IntoIter<Rc<Var>, VariableFixture<'a>> {
+    pub(crate) fn into_iter(self) -> indexmap::map::IntoIter<Rc<Var>, VariableFixture<'a>> {
         self.perm_vars.into_iter()
     }
 
@@ -226,11 +226,11 @@ impl<'a> VariableFixtures<'a> {
         self.perm_vars.values()
     }
 
-    pub fn size(&self) -> usize {
+    pub(crate) fn size(&self) -> usize {
         self.perm_vars.len()
     }
 
-    pub fn set_perm_vals(&self, has_deep_cuts: bool) {
+    pub(crate) fn set_perm_vals(&self, has_deep_cuts: bool) {
         let mut values_vec: Vec<_> = self
             .values()
             .filter_map(|ref v| match &v.0 {
@@ -252,27 +252,27 @@ impl<'a> VariableFixtures<'a> {
 }
 
 #[derive(Debug)]
-pub struct UnsafeVarMarker {
+pub(crate) struct UnsafeVarMarker {
-    pub unsafe_vars: IndexMap<RegType, usize>,
+    pub(crate) unsafe_vars: IndexMap<RegType, usize>,
-    pub safe_vars: IndexSet<RegType>,
+    pub(crate) safe_vars: IndexSet<RegType>,
 }
 
 impl UnsafeVarMarker {
-    pub fn new() -> Self {
+    pub(crate) fn new() -> Self {
         UnsafeVarMarker {
             unsafe_vars: IndexMap::new(),
             safe_vars: IndexSet::new(),
         }
     }
 
-    pub fn from_safe_vars(safe_vars: IndexSet<RegType>) -> Self {
+    pub(crate) fn from_safe_vars(safe_vars: IndexSet<RegType>) -> Self {
         UnsafeVarMarker {
             unsafe_vars: IndexMap::new(),
             safe_vars,
         }
     }
 
-    pub fn mark_safe_vars(&mut self, query_instr: &QueryInstruction) -> bool {
+    pub(crate) fn mark_safe_vars(&mut self, query_instr: &QueryInstruction) -> bool {
         match query_instr {
             &QueryInstruction::PutVariable(r @ RegType::Temp(_), _)
             | &QueryInstruction::SetVariable(r) => {
@@ -283,7 +283,7 @@ impl UnsafeVarMarker {
         }
     }
 
-    pub fn mark_phase(&mut self, query_instr: &QueryInstruction, phase: usize) {
+    pub(crate) fn mark_phase(&mut self, query_instr: &QueryInstruction, phase: usize) {
         match query_instr {
             &QueryInstruction::PutValue(r @ RegType::Perm(_), _)
             | &QueryInstruction::SetValue(r) => {
@@ -294,7 +294,7 @@ impl UnsafeVarMarker {
         }
     }
 
-    pub fn mark_unsafe_vars(&mut self, query_instr: &mut QueryInstruction, phase: usize) {
+    pub(crate) fn mark_unsafe_vars(&mut self, query_instr: &mut QueryInstruction, phase: usize) {
         match query_instr {
             &mut QueryInstruction::PutValue(RegType::Perm(i), arg) => {
                 if let Some(p) = self.unsafe_vars.swap_remove(&RegType::Perm(i)) {

src/forms.rs

@@ -18,16 +18,16 @@ use std::ops::AddAssign;
 use std::path::PathBuf;
 use std::rc::Rc;
 
-pub type PredicateKey = (ClauseName, usize); // name, arity.
+pub(crate) type PredicateKey = (ClauseName, usize); // name, arity.
 
-pub type Predicate = Vec<PredicateClause>;
+pub(crate) type Predicate = Vec<PredicateClause>;
 
 // vars of predicate, toplevel offset.  Vec<Term> is always a vector
 // of vars (we get their adjoining cells this way).
-pub type JumpStub = Vec<Term>;
+pub(crate) type JumpStub = Vec<Term>;
 
 #[derive(Debug, Clone)]
-pub enum TopLevel {
+pub(crate) enum TopLevel {
     Fact(Term), // Term, line_num, col_num
     Predicate(Predicate),
     Query(Vec<QueryTerm>),
@@ -35,14 +35,14 @@ pub enum TopLevel {
 }
 
 #[derive(Debug, Clone, Copy)]
-pub enum AppendOrPrepend {
+pub(crate) enum AppendOrPrepend {
     Append,
     Prepend,
 }
 
 impl AppendOrPrepend {
     #[inline]
-    pub fn is_append(self) -> bool {
+    pub(crate) fn is_append(self) -> bool {
         match self {
             AppendOrPrepend::Append => true,
             AppendOrPrepend::Prepend => false,
@@ -51,14 +51,14 @@ impl AppendOrPrepend {
 }
 
 #[derive(Debug, Clone, Copy)]
-pub enum Level {
+pub(crate) enum Level {
     Deep,
     Root,
     Shallow,
 }
 
 impl Level {
-    pub fn child_level(self) -> Level {
+    pub(crate) fn child_level(self) -> Level {
         match self {
             Level::Root => Level::Shallow,
             _ => Level::Deep,
@@ -67,7 +67,7 @@ impl Level {
 }
 
 #[derive(Debug, Clone)]
-pub enum QueryTerm {
+pub(crate) enum QueryTerm {
     // register, clause type, subterms, use default call policy.
     Clause(Cell<RegType>, ClauseType, Vec<Box<Term>>, bool),
     BlockedCut, // a cut which is 'blocked by letters', like the P term in P -> Q.
@@ -77,14 +77,14 @@ pub enum QueryTerm {
 }
 
 impl QueryTerm {
-    pub fn set_default_caller(&mut self) {
+    pub(crate) fn set_default_caller(&mut self) {
         match self {
             &mut QueryTerm::Clause(_, _, _, ref mut use_default_cp) => *use_default_cp = true,
             _ => {}
         }
     }
 
-    pub fn arity(&self) -> usize {
+    pub(crate) fn arity(&self) -> usize {
         match self {
             &QueryTerm::Clause(_, _, ref subterms, ..) => subterms.len(),
             &QueryTerm::BlockedCut | &QueryTerm::UnblockedCut(..) => 0,
@@ -95,28 +95,30 @@ impl QueryTerm {
 }
 
 #[derive(Debug, Clone)]
-pub struct Rule {
+pub(crate) struct Rule {
-    pub head: (ClauseName, Vec<Box<Term>>, QueryTerm),
+    pub(crate) head: (ClauseName, Vec<Box<Term>>, QueryTerm),
-    pub clauses: Vec<QueryTerm>,
+    pub(crate) clauses: Vec<QueryTerm>,
 }
 
 #[derive(Clone, Debug, Hash)]
-pub enum ListingSource {
+pub(crate) enum ListingSource {
     DynamicallyGenerated,
     File(ClauseName, PathBuf), // filename, path
     User,
 }
 
 impl ListingSource {
-    pub fn from_file_and_path(filename: ClauseName, path_buf: PathBuf) -> Self {
+    pub(crate) fn from_file_and_path(filename: ClauseName, path_buf: PathBuf) -> Self {
         ListingSource::File(filename, path_buf)
     }
 }
 
-pub trait ClauseInfo {
+pub(crate) trait ClauseInfo {
     fn is_consistent(&self, clauses: &PredicateQueue) -> bool {
         match clauses.first() {
-            Some(cl) => self.name() == ClauseInfo::name(cl) && self.arity() == ClauseInfo::arity(cl),
+            Some(cl) => {
+                self.name() == ClauseInfo::name(cl) && self.arity() == ClauseInfo::arity(cl)
+            }
             None => true,
         }
     }
@@ -198,17 +200,17 @@ impl ClauseInfo for PredicateClause {
     }
 }
 
-// pub type CompiledResult = (Predicate, VecDeque<TopLevel>);
+// pub(crate) type CompiledResult = (Predicate, VecDeque<TopLevel>);
 
 #[derive(Debug, Clone)]
-pub enum PredicateClause {
+pub(crate) enum PredicateClause {
     Fact(Term),
     Rule(Rule),
 }
 
 impl PredicateClause {
     // TODO: add this to `Term` in `prolog_parser` like `first_arg`.
-    pub fn args(&self) -> Option<&[Box<Term>]> {
+    pub(crate) fn args(&self) -> Option<&[Box<Term>]> {
         match *self {
             PredicateClause::Fact(ref term, ..) => match term {
                 Term::Clause(_, _, args, _) => Some(&args),
@@ -226,13 +228,13 @@ impl PredicateClause {
 }
 
 #[derive(Debug, Clone)]
-pub enum ModuleSource {
+pub(crate) enum ModuleSource {
     Library(ClauseName),
     File(ClauseName),
 }
 
 impl ModuleSource {
-    pub fn as_functor_stub(&self) -> MachineStub {
+    pub(crate) fn as_functor_stub(&self) -> MachineStub {
         match self {
             ModuleSource::Library(ref name) => {
                 functor!("library", [clause_name(name.clone())])
@@ -244,18 +246,18 @@ impl ModuleSource {
     }
 }
 
-// pub type ScopedPredicateKey = (ClauseName, PredicateKey); // module name, predicate indicator.
+// pub(crate) type ScopedPredicateKey = (ClauseName, PredicateKey); // module name, predicate indicator.
 
 /*
 #[derive(Debug, Clone)]
-pub enum MultiFileIndicator {
+pub(crate) enum MultiFileIndicator {
     LocalScoped(ClauseName, usize), // name, arity
     ModuleScoped(ScopedPredicateKey),
 }
 */
 
 #[derive(Clone, Copy, Hash, Debug)]
-pub enum MetaSpec {
+pub(crate) enum MetaSpec {
     Minus,
     Plus,
     Either,
@@ -263,7 +265,7 @@ pub enum MetaSpec {
 }
 
 #[derive(Debug, Clone)]
-pub enum Declaration {
+pub(crate) enum Declaration {
     Dynamic(ClauseName, usize),
     MetaPredicate(ClauseName, ClauseName, Vec<MetaSpec>), // module name, name, meta-specs
     Module(ModuleDecl),
@@ -274,20 +276,20 @@ pub enum Declaration {
 }
 
 #[derive(Debug, Clone, Eq, Hash, PartialEq, Ord, PartialOrd)]
-pub struct OpDecl {
+pub(crate) struct OpDecl {
-    pub prec: usize,
+    pub(crate) prec: usize,
-    pub spec: Specifier,
+    pub(crate) spec: Specifier,
-    pub name: ClauseName,
+    pub(crate) name: ClauseName,
 }
 
 impl OpDecl {
     #[inline]
-    pub fn new(prec: usize, spec: Specifier, name: ClauseName) -> Self {
+    pub(crate) fn new(prec: usize, spec: Specifier, name: ClauseName) -> Self {
         Self { prec, spec, name }
     }
 
     #[inline]
-    pub fn remove(&mut self, op_dir: &mut OpDir) {
+    pub(crate) fn remove(&mut self, op_dir: &mut OpDir) {
         let prec = self.prec;
         self.prec = 0;
 
@@ -296,7 +298,7 @@ impl OpDecl {
     }
 
     #[inline]
-    pub fn fixity(&self) -> Fixity {
+    pub(crate) fn fixity(&self) -> Fixity {
         match self.spec {
             XFY | XFX | YFX => Fixity::In,
             XF | YF => Fixity::Post,
@@ -305,7 +307,7 @@ impl OpDecl {
         }
     }
 
-    pub fn insert_into_op_dir(&self, op_dir: &mut OpDir) -> Option<(usize, Specifier)> {
+    pub(crate) fn insert_into_op_dir(&self, op_dir: &mut OpDir) -> Option<(usize, Specifier)> {
         let key = (self.name.clone(), self.fixity());
 
         match op_dir.get(&key) {
@@ -320,7 +322,7 @@ impl OpDecl {
             .map(|op_dir_value| op_dir_value.shared_op_desc().get())
     }
 
-    pub fn submit(
+    pub(crate) fn submit(
         &self,
         existing_desc: Option<OpDesc>,
         op_dir: &mut OpDir,
@@ -348,7 +350,7 @@ impl OpDecl {
     }
 }
 
-pub fn fetch_atom_op_spec(
+pub(crate) fn fetch_atom_op_spec(
     name: ClauseName,
     spec: Option<SharedOpDesc>,
     op_dir: &OpDir,
@@ -357,7 +359,7 @@ pub fn fetch_atom_op_spec(
         .or_else(|| fetch_op_spec_from_existing(name, 2, spec, op_dir))
 }
 
-pub fn fetch_op_spec_from_existing(
+pub(crate) fn fetch_op_spec_from_existing(
     name: ClauseName,
     arity: usize,
     spec: Option<SharedOpDesc>,
@@ -375,7 +377,11 @@ pub fn fetch_op_spec_from_existing(
     spec.or_else(|| fetch_op_spec(name, arity, op_dir))
 }
 
-pub fn fetch_op_spec(name: ClauseName, arity: usize, op_dir: &OpDir) -> Option<SharedOpDesc> {
+pub(crate) fn fetch_op_spec(
+    name: ClauseName,
+    arity: usize,
+    op_dir: &OpDir,
+) -> Option<SharedOpDesc> {
     match arity {
         2 => op_dir
             .get(&(name, Fixity::In))
@@ -407,35 +413,35 @@ pub fn fetch_op_spec(name: ClauseName, arity: usize, op_dir: &OpDir) -> Option<S
     }
 }
 
-pub type ModuleDir = IndexMap<ClauseName, Module>;
+pub(crate) type ModuleDir = IndexMap<ClauseName, Module>;
 
 #[derive(Debug, Clone, Eq, Hash, PartialEq)]
-pub enum ModuleExport {
+pub(crate) enum ModuleExport {
     OpDecl(OpDecl),
     PredicateKey(PredicateKey),
 }
 
 #[derive(Debug, Clone)]
-pub struct ModuleDecl {
+pub(crate) struct ModuleDecl {
-    pub name: ClauseName,
+    pub(crate) name: ClauseName,
-    pub exports: Vec<ModuleExport>,
+    pub(crate) exports: Vec<ModuleExport>,
 }
 
 #[derive(Debug)]
-pub struct Module {
+pub(crate) struct Module {
-    pub module_decl: ModuleDecl,
+    pub(crate) module_decl: ModuleDecl,
-    pub code_dir: CodeDir,
+    pub(crate) code_dir: CodeDir,
-    pub op_dir: OpDir,
+    pub(crate) op_dir: OpDir,
-    pub meta_predicates: MetaPredicateDir,
+    pub(crate) meta_predicates: MetaPredicateDir,
-    pub extensible_predicates: ExtensiblePredicates,
+    pub(crate) extensible_predicates: ExtensiblePredicates,
-    pub local_extensible_predicates: LocalExtensiblePredicates,
+    pub(crate) local_extensible_predicates: LocalExtensiblePredicates,
-    pub is_impromptu_module: bool,
+    pub(crate) is_impromptu_module: bool,
-    pub listing_src: ListingSource,
+    pub(crate) listing_src: ListingSource,
 }
 
 // Module's and related types are defined in forms.
 impl Module {
-    pub fn new(module_decl: ModuleDecl, listing_src: ListingSource) -> Self {
+    pub(crate) fn new(module_decl: ModuleDecl, listing_src: ListingSource) -> Self {
         Module {
             module_decl,
             code_dir: CodeDir::new(),
@@ -450,7 +456,7 @@ impl Module {
 }
 
 #[derive(Debug, Clone)]
-pub enum Number {
+pub(crate) enum Number {
     Float(OrderedFloat<f64>),
     Integer(Rc<Integer>),
     Rational(Rc<Rational>),
@@ -510,7 +516,7 @@ impl Into<HeapCellValue> for Number {
 
 impl Number {
     #[inline]
-    pub fn is_positive(&self) -> bool {
+    pub(crate) fn is_positive(&self) -> bool {
         match self {
             &Number::Fixnum(n) => n > 0,
             &Number::Integer(ref n) => &**n > &0,
@@ -520,7 +526,7 @@ impl Number {
     }
 
     #[inline]
-    pub fn is_negative(&self) -> bool {
+    pub(crate) fn is_negative(&self) -> bool {
         match self {
             &Number::Fixnum(n) => n < 0,
             &Number::Integer(ref n) => &**n < &0,
@@ -530,7 +536,7 @@ impl Number {
     }
 
     #[inline]
-    pub fn is_zero(&self) -> bool {
+    pub(crate) fn is_zero(&self) -> bool {
         match self {
             &Number::Fixnum(n) => n == 0,
             &Number::Integer(ref n) => &**n == &0,
@@ -540,7 +546,7 @@ impl Number {
     }
 
     #[inline]
-    pub fn abs(self) -> Self {
+    pub(crate) fn abs(self) -> Self {
         match self {
             Number::Fixnum(n) => {
                 if let Some(n) = n.checked_abs() {
@@ -557,7 +563,7 @@ impl Number {
 }
 
 #[derive(Debug, Clone)]
-pub enum OptArgIndexKey {
+pub(crate) enum OptArgIndexKey {
     Constant(usize, usize, Constant, Vec<Constant>), // index, IndexingCode location, opt arg, alternatives
     List(usize, usize),                              // index, IndexingCode location
     None,
@@ -566,12 +572,12 @@ pub enum OptArgIndexKey {
 
 impl OptArgIndexKey {
     #[inline]
-    pub fn take(&mut self) -> OptArgIndexKey {
+    pub(crate) fn take(&mut self) -> OptArgIndexKey {
         std::mem::replace(self, OptArgIndexKey::None)
     }
 
     #[inline]
-    pub fn arg_num(&self) -> usize {
+    pub(crate) fn arg_num(&self) -> usize {
         match &self {
             OptArgIndexKey::Constant(arg_num, ..)
             | OptArgIndexKey::Structure(arg_num, ..)
@@ -584,12 +590,12 @@ impl OptArgIndexKey {
     }
 
     #[inline]
-    pub fn is_some(&self) -> bool {
+    pub(crate) fn is_some(&self) -> bool {
         self.switch_on_term_loc().is_some()
     }
 
     #[inline]
-    pub fn switch_on_term_loc(&self) -> Option<usize> {
+    pub(crate) fn switch_on_term_loc(&self) -> Option<usize> {
         match &self {
             OptArgIndexKey::Constant(_, loc, ..)
             | OptArgIndexKey::Structure(_, loc, ..)
@@ -599,7 +605,7 @@ impl OptArgIndexKey {
     }
 
     #[inline]
-    pub fn set_switch_on_term_loc(&mut self, value: usize) {
+    pub(crate) fn set_switch_on_term_loc(&mut self, value: usize) {
         match self {
             OptArgIndexKey::Constant(_, ref mut loc, ..)
             | OptArgIndexKey::Structure(_, ref mut loc, ..)
@@ -626,14 +632,14 @@ impl AddAssign<usize> for OptArgIndexKey {
 }
 
 #[derive(Clone, Debug)]
-pub struct ClauseIndexInfo {
+pub(crate) struct ClauseIndexInfo {
-    pub clause_start: usize,
+    pub(crate) clause_start: usize,
-    pub opt_arg_index_key: OptArgIndexKey,
+    pub(crate) opt_arg_index_key: OptArgIndexKey,
 }
 
 impl ClauseIndexInfo {
     #[inline]
-    pub fn new(clause_start: usize) -> Self {
+    pub(crate) fn new(clause_start: usize) -> Self {
         Self {
             clause_start,
             opt_arg_index_key: OptArgIndexKey::None,
@@ -643,12 +649,12 @@ impl ClauseIndexInfo {
 }
 
 #[derive(Clone, Copy, Debug)]
-pub struct PredicateInfo {
+pub(crate) struct PredicateInfo {
-    pub is_extensible: bool,
+    pub(crate) is_extensible: bool,
-    pub is_discontiguous: bool,
+    pub(crate) is_discontiguous: bool,
-    pub is_dynamic: bool,
+    pub(crate) is_dynamic: bool,
-    pub is_multifile: bool,
+    pub(crate) is_multifile: bool,
-    pub has_clauses: bool,
+    pub(crate) has_clauses: bool,
 }
 
 impl Default for PredicateInfo {
@@ -666,30 +672,30 @@ impl Default for PredicateInfo {
 
 impl PredicateInfo {
     #[inline]
-    pub fn compile_incrementally(&self) -> bool {
+    pub(crate) fn compile_incrementally(&self) -> bool {
         let base = self.is_extensible && self.has_clauses;
         base && (self.is_discontiguous || self.is_multifile)
     }
 
     #[inline]
-    pub fn must_retract_local_clauses(&self) -> bool {
+    pub(crate) fn must_retract_local_clauses(&self) -> bool {
         self.is_extensible && self.has_clauses && !self.is_discontiguous
     }
 }
 
 #[derive(Debug)]
-pub struct PredicateSkeleton {
+pub(crate) struct PredicateSkeleton {
-    pub is_discontiguous: bool,
+    pub(crate) is_discontiguous: bool,
-    pub is_dynamic: bool,
+    pub(crate) is_dynamic: bool,
-    pub is_multifile: bool,
+    pub(crate) is_multifile: bool,
-    pub clauses: SliceDeque<ClauseIndexInfo>,
+    pub(crate) clauses: SliceDeque<ClauseIndexInfo>,
-    pub clause_clause_locs: SliceDeque<usize>,
+    pub(crate) clause_clause_locs: SliceDeque<usize>,
-    pub clause_assert_margin: usize,
+    pub(crate) clause_assert_margin: usize,
 }
 
 impl PredicateSkeleton {
     #[inline]
-    pub fn new() -> Self {
+    pub(crate) fn new() -> Self {
         PredicateSkeleton {
             is_discontiguous: false,
             is_dynamic: false,
@@ -701,7 +707,7 @@ impl PredicateSkeleton {
     }
 
     #[inline]
-    pub fn predicate_info(&self) -> PredicateInfo {
+    pub(crate) fn predicate_info(&self) -> PredicateInfo {
         PredicateInfo {
             is_extensible: true,
             is_discontiguous: self.is_discontiguous,
@@ -712,13 +718,13 @@ impl PredicateSkeleton {
     }
 
     #[inline]
-    pub fn reset(&mut self) {
+    pub(crate) fn reset(&mut self) {
         self.clauses.clear();
         self.clause_clause_locs.clear();
         self.clause_assert_margin = 0;
     }
 
-    pub fn target_pos_of_clause_clause_loc(
+    pub(crate) fn target_pos_of_clause_clause_loc(
         &self,
         clause_clause_loc: usize,
     ) -> Option<usize> {
@@ -727,10 +733,10 @@ impl PredicateSkeleton {
 
         match search_result {
             Ok(loc) => Some(loc),
-            Err(_)  => self.clause_clause_locs[self.clause_assert_margin..]
+            Err(_) => self.clause_clause_locs[self.clause_assert_margin..]
                 .binary_search_by(|loc| loc.cmp(&clause_clause_loc))
                 .map(|loc| loc + self.clause_assert_margin)
-                .ok()
+                .ok(),
         }
     }
 }

src/heap_iter.rs

@@ -8,13 +8,13 @@ use std::ops::Deref;
 use std::vec::Vec;
 
 #[derive(Debug)]
-pub struct HCPreOrderIterator<'a> {
+pub(crate) struct HCPreOrderIterator<'a> {
-    pub machine_st: &'a MachineState,
+    pub(crate) machine_st: &'a MachineState,
-    pub state_stack: Vec<Addr>,
+    pub(crate) state_stack: Vec<Addr>,
 }
 
 impl<'a> HCPreOrderIterator<'a> {
-    pub fn new(machine_st: &'a MachineState, a: Addr) -> Self {
+    pub(crate) fn new(machine_st: &'a MachineState, a: Addr) -> Self {
         HCPreOrderIterator {
             machine_st,
             state_stack: vec![a],
@@ -22,7 +22,7 @@ impl<'a> HCPreOrderIterator<'a> {
     }
 
     #[inline]
-    pub fn machine_st(&self) -> &MachineState {
+    pub(crate) fn machine_st(&self) -> &MachineState {
         &self.machine_st
     }
 
@@ -116,7 +116,7 @@ impl<'a> Iterator for HCPreOrderIterator<'a> {
     }
 }
 
-pub trait MutStackHCIterator<'b>
+pub(crate) trait MutStackHCIterator<'b>
 where
     Self: Iterator,
 {
@@ -126,7 +126,7 @@ where
 }
 
 #[derive(Debug)]
-pub struct HCPostOrderIterator<'a> {
+pub(crate) struct HCPostOrderIterator<'a> {
     base_iter: HCPreOrderIterator<'a>,
     parent_stack: Vec<(usize, Addr)>, // number of children, parent node.
 }
@@ -140,7 +140,7 @@ impl<'a> Deref for HCPostOrderIterator<'a> {
 }
 
 impl<'a> HCPostOrderIterator<'a> {
-    pub fn new(base_iter: HCPreOrderIterator<'a>) -> Self {
+    pub(crate) fn new(base_iter: HCPreOrderIterator<'a>) -> Self {
         HCPostOrderIterator {
             base_iter,
             parent_stack: vec![],
@@ -201,19 +201,19 @@ impl<'a> Iterator for HCPostOrderIterator<'a> {
 }
 
 impl MachineState {
-    pub fn pre_order_iter<'a>(&'a self, a: Addr) -> HCPreOrderIterator<'a> {
+    pub(crate) fn pre_order_iter<'a>(&'a self, a: Addr) -> HCPreOrderIterator<'a> {
         HCPreOrderIterator::new(self, a)
     }
 
-    pub fn post_order_iter<'a>(&'a self, a: Addr) -> HCPostOrderIterator<'a> {
+    pub(crate) fn post_order_iter<'a>(&'a self, a: Addr) -> HCPostOrderIterator<'a> {
         HCPostOrderIterator::new(HCPreOrderIterator::new(self, a))
     }
 
-    pub fn acyclic_pre_order_iter<'a>(&'a self, a: Addr) -> HCAcyclicIterator<'a> {
+    pub(crate) fn acyclic_pre_order_iter<'a>(&'a self, a: Addr) -> HCAcyclicIterator<'a> {
         HCAcyclicIterator::new(HCPreOrderIterator::new(self, a))
     }
 
-    pub fn zipped_acyclic_pre_order_iter<'a>(
+    pub(crate) fn zipped_acyclic_pre_order_iter<'a>(
         &'a self,
         a1: Addr,
         a2: Addr,
@@ -234,13 +234,13 @@ impl<'b, 'a: 'b> MutStackHCIterator<'b> for HCPreOrderIterator<'a> {
 }
 
 #[derive(Debug)]
-pub struct HCAcyclicIterator<'a> {
+pub(crate) struct HCAcyclicIterator<'a> {
     iter: HCPreOrderIterator<'a>,
     seen: IndexSet<Addr>,
 }
 
 impl<'a> HCAcyclicIterator<'a> {
-    pub fn new(iter: HCPreOrderIterator<'a>) -> Self {
+    pub(crate) fn new(iter: HCPreOrderIterator<'a>) -> Self {
         HCAcyclicIterator {
             iter,
             seen: IndexSet::new(),
@@ -282,11 +282,11 @@ impl<'a> Iterator for HCAcyclicIterator<'a> {
 }
 
 #[derive(Debug)]
-pub struct HCZippedAcyclicIterator<'a> {
+pub(crate) struct HCZippedAcyclicIterator<'a> {
     i1: HCPreOrderIterator<'a>,
     i2: HCPreOrderIterator<'a>,
     seen: IndexSet<(Addr, Addr)>,
-    pub first_to_expire: Ordering,
+    pub(crate) first_to_expire: Ordering,
 }
 
 impl<'b, 'a: 'b> MutStackHCIterator<'b> for HCZippedAcyclicIterator<'a> {
@@ -298,7 +298,7 @@ impl<'b, 'a: 'b> MutStackHCIterator<'b> for HCZippedAcyclicIterator<'a> {
 }
 
 impl<'a> HCZippedAcyclicIterator<'a> {
-    pub fn new(i1: HCPreOrderIterator<'a>, i2: HCPreOrderIterator<'a>) -> Self {
+    pub(crate) fn new(i1: HCPreOrderIterator<'a>, i2: HCPreOrderIterator<'a>) -> Self {
         HCZippedAcyclicIterator {
             i1,
             i2,

src/heap_print.rs

@@ -27,7 +27,7 @@ use std::rc::Rc;
 
 /* contains the location, name, precision and Specifier of the parent op. */
 #[derive(Debug, Clone)]
-pub enum DirectedOp {
+pub(crate) enum DirectedOp {
     Left(ClauseName, SharedOpDesc),
     Right(ClauseName, SharedOpDesc),
 }
@@ -190,7 +190,7 @@ enum TokenOrRedirect {
     HeadTailSeparator,
 }
 
-pub trait HCValueOutputter {
+pub(crate) trait HCValueOutputter {
     type Output;
 
     fn new() -> Self;
@@ -207,7 +207,7 @@ pub trait HCValueOutputter {
 }
 
 #[derive(Debug)]
-pub struct PrinterOutputter {
+pub(crate) struct PrinterOutputter {
     contents: String,
 }
 
@@ -306,7 +306,7 @@ fn numbervar(n: Integer) -> Var {
 }
 
 impl MachineState {
-    pub fn numbervar(&self, offset: &Integer, addr: Addr) -> Option<Var> {
+    pub(crate) fn numbervar(&self, offset: &Integer, addr: Addr) -> Option<Var> {
         let addr = self.store(self.deref(addr));
 
         match Number::try_from((addr, &self.heap)) {
@@ -332,7 +332,7 @@ impl MachineState {
 type ReverseHeapVarDict = IndexMap<Addr, Rc<Var>>;
 
 #[derive(Debug)]
-pub struct HCPrinter<'a, Outputter> {
+pub(crate) struct HCPrinter<'a, Outputter> {
     outputter: Outputter,
     machine_st: &'a MachineState,
     op_dir: &'a OpDir,
@@ -363,7 +363,7 @@ macro_rules! push_space_if_amb {
     };
 }
 
-pub fn requires_space(atom: &str, op: &str) -> bool {
+pub(crate) fn requires_space(atom: &str, op: &str) -> bool {
     match atom.chars().last() {
         Some(ac) => op
             .chars()
@@ -473,7 +473,7 @@ fn functor_location(addr: &Addr) -> Option<usize> {
 }
 
 impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
-    pub fn new(machine_st: &'a MachineState, op_dir: &'a OpDir, output: Outputter) -> Self {
+    pub(crate) fn new(machine_st: &'a MachineState, op_dir: &'a OpDir, output: Outputter) -> Self {
         HCPrinter {
             outputter: output,
             machine_st,
@@ -495,7 +495,7 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
         }
     }
     /*
-        pub fn from_heap_locs(
+        pub(crate) fn from_heap_locs(
             machine_st: &'a MachineState,
             op_dir: &'a OpDir,
             output: Outputter,
@@ -513,13 +513,13 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
         }
     */
     /*
-        pub fn drop_toplevel_spec(&mut self) {
+        pub(crate) fn drop_toplevel_spec(&mut self) {
             self.toplevel_spec = None;
         }
     */
     /*
         #[inline]
-        pub fn see_all_locs(&mut self) {
+        pub(crate) fn see_all_locs(&mut self) {
             for key in self.heap_locs.keys().cloned() {
                 self.printed_vars.insert(key);
             }
@@ -1517,7 +1517,7 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
         }
     }
 
-    pub fn print(mut self, addr: Addr) -> Outputter {
+    pub(crate) fn print(mut self, addr: Addr) -> Outputter {
         let mut iter = self.machine_st.pre_order_iter(addr);
 
         loop {

src/indexing.rs

@@ -17,7 +17,7 @@ use std::mem;
 use std::rc::Rc;
 
 #[derive(Debug, Clone, Copy)]
-pub enum IndexingCodePtr {
+pub(crate) enum IndexingCodePtr {
     External(usize), // the index points past the indexing instruction prelude.
     DynamicExternal(usize), // an External index of a dynamic predicate, potentially invalidated by retraction.
     Fail,
@@ -585,7 +585,7 @@ impl<'a> IndexingCodeMergingPtr<'a> {
     }
 }
 
-pub fn merge_clause_index(
+pub(crate) 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.
@@ -638,7 +638,7 @@ pub fn merge_clause_index(
     }
 }
 
-pub fn remove_constant_indices(
+pub(crate) fn remove_constant_indices(
     constant: &Constant,
     overlapping_constants: &[Constant],
     indexing_code: &mut Vec<IndexingLine>,
@@ -778,7 +778,7 @@ pub fn remove_constant_indices(
     }
 }
 
-pub fn remove_structure_index(
+pub(crate) fn remove_structure_index(
     name: &ClauseName,
     arity: usize,
     indexing_code: &mut Vec<IndexingLine>,
@@ -917,7 +917,7 @@ pub fn remove_structure_index(
     }
 }
 
-pub fn remove_list_index(indexing_code: &mut Vec<IndexingLine>, offset: usize) {
+pub(crate) fn remove_list_index(indexing_code: &mut Vec<IndexingLine>, offset: usize) {
     let mut index = 0;
 
     match &mut indexing_code[index] {
@@ -995,7 +995,7 @@ pub fn remove_list_index(indexing_code: &mut Vec<IndexingLine>, offset: usize) {
     }
 }
 
-pub fn remove_index(
+pub(crate) fn remove_index(
     opt_arg_index_key: &OptArgIndexKey,
     indexing_code: &mut Vec<IndexingLine>,
     clause_loc: usize,
@@ -1065,7 +1065,7 @@ fn uncap_choice_seq_with_try(prelude: &mut [IndexedChoiceInstruction]) {
     });
 }
 
-pub fn constant_key_alternatives(constant: &Constant, atom_tbl: TabledData<Atom>) -> Vec<Constant> {
+pub(crate) fn constant_key_alternatives(constant: &Constant, atom_tbl: TabledData<Atom>) -> Vec<Constant> {
     let mut constants = vec![];
 
     match constant {
@@ -1128,7 +1128,7 @@ pub(crate) struct DynamicCodeIndices {
     structures: IndexMap<(ClauseName, usize), SliceDeque<usize>>,
 }
 
-pub trait Indexer {
+pub(crate) trait Indexer {
     type ThirdLevelIndex;
 
     fn new() -> Self;
@@ -1383,14 +1383,14 @@ impl Indexer for DynamicCodeIndices {
 }
 
 #[derive(Debug)]
-pub struct CodeOffsets<I: Indexer> {
+pub(crate) struct CodeOffsets<I: Indexer> {
     atom_tbl: TabledData<Atom>,
     indices: I,
     optimal_index: usize,
 }
 
 impl<I: Indexer> CodeOffsets<I> {
-    pub fn new(
+    pub(crate) fn new(
         atom_tbl: TabledData<Atom>,
         indices: I,
         optimal_index: usize,
@@ -1440,7 +1440,7 @@ impl<I: Indexer> CodeOffsets<I> {
         code_len
     }
 
-    pub fn index_term(
+    pub(crate) fn index_term(
         &mut self,
         optimal_arg: &Term,
         index: usize,
@@ -1472,7 +1472,7 @@ impl<I: Indexer> CodeOffsets<I> {
         }
     }
 
-    pub fn no_indices(&mut self) -> bool {
+    pub(crate) fn no_indices(&mut self) -> bool {
         let no_constants = self.indices.constants().is_empty();
         let no_structures = self.indices.structures().is_empty();
         let no_lists = self.indices.lists().is_empty();
@@ -1480,7 +1480,7 @@ impl<I: Indexer> CodeOffsets<I> {
         no_constants && no_structures && no_lists
     }
 
-    pub fn compute_indices(mut self, skip_stub_try_me_else: bool) -> Vec<IndexingLine> {
+    pub(crate) fn compute_indices(mut self, skip_stub_try_me_else: bool) -> Vec<IndexingLine> {
         if self.no_indices() {
             return vec![];
         }
@@ -1488,7 +1488,7 @@ impl<I: Indexer> CodeOffsets<I> {
         let mut prelude = sdeq![];
 
         let mut emitted_switch_on_structure = false;
-        let mut emitted_switch_on_constant  = false;
+        let mut emitted_switch_on_constant = false;
 
         let mut lst_loc = I::switch_on_list(self.indices.lists(), &mut prelude);
 

src/instructions.rs

@@ -47,7 +47,7 @@ impl ArithmeticTerm {
 }
 
 #[derive(Debug, Clone, Copy)]
-pub enum NextOrFail {
+pub(crate) enum NextOrFail {
     Next(usize),
     Fail(usize),
 }
@@ -64,13 +64,13 @@ impl NextOrFail {
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
-pub enum Death {
+pub(crate) enum Death {
     Finite(usize),
     Infinity,
 }
 
 #[derive(Debug)]
-pub enum ChoiceInstruction {
+pub(crate) enum ChoiceInstruction {
     DynamicElse(usize, Death, NextOrFail),
     DynamicInternalElse(usize, Death, NextOrFail),
     DefaultRetryMeElse(usize),
@@ -81,7 +81,7 @@ pub enum ChoiceInstruction {
 }
 
 impl ChoiceInstruction {
-    pub fn to_functor(&self, h: usize) -> MachineStub {
+    pub(crate) fn to_functor(&self, h: usize) -> MachineStub {
         match self {
             &ChoiceInstruction::DynamicElse(birth, death, next_or_fail) => {
                 match (death, next_or_fail) {
@@ -171,7 +171,7 @@ impl ChoiceInstruction {
 }
 
 #[derive(Debug)]
-pub enum CutInstruction {
+pub(crate) enum CutInstruction {
     Cut(RegType),
     GetLevel(RegType),
     GetLevelAndUnify(RegType),
@@ -179,7 +179,7 @@ pub enum CutInstruction {
 }
 
 impl CutInstruction {
-    pub fn to_functor(&self, h: usize) -> MachineStub {
+    pub(crate) fn to_functor(&self, h: usize) -> MachineStub {
         match self {
             &CutInstruction::Cut(r) => {
                 let rt_stub = reg_type_into_functor(r);
@@ -201,14 +201,14 @@ impl CutInstruction {
 }
 
 #[derive(Clone, Copy, Debug)]
-pub enum IndexedChoiceInstruction {
+pub(crate) enum IndexedChoiceInstruction {
     Retry(usize),
     Trust(usize),
     Try(usize),
 }
 
 impl IndexedChoiceInstruction {
-    pub fn offset(&self) -> usize {
+    pub(crate) fn offset(&self) -> usize {
         match self {
             &IndexedChoiceInstruction::Retry(offset) => offset,
             &IndexedChoiceInstruction::Trust(offset) => offset,
@@ -216,7 +216,7 @@ impl IndexedChoiceInstruction {
         }
     }
 
-    pub fn to_functor(&self) -> MachineStub {
+    pub(crate) fn to_functor(&self) -> MachineStub {
         match self {
             &IndexedChoiceInstruction::Try(offset) => {
                 functor!("try", [integer(offset)])
@@ -233,7 +233,7 @@ impl IndexedChoiceInstruction {
 
 /// A `Line` is an instruction (cf. page 98 of wambook).
 #[derive(Debug)]
-pub enum IndexingLine {
+pub(crate) enum IndexingLine {
     Indexing(IndexingInstruction),
     IndexedChoice(SliceDeque<IndexedChoiceInstruction>),
     DynamicIndexedChoice(SliceDeque<usize>),
@@ -254,7 +254,7 @@ impl From<SliceDeque<IndexedChoiceInstruction>> for IndexingLine {
 }
 
 #[derive(Debug)]
-pub enum Line {
+pub(crate) enum Line {
     Arithmetic(ArithmeticInstruction),
     Choice(ChoiceInstruction),
     Control(ControlInstruction),
@@ -268,7 +268,7 @@ pub enum Line {
 
 impl Line {
     #[inline]
-    pub fn is_head_instr(&self) -> bool {
+    pub(crate) fn is_head_instr(&self) -> bool {
         match self {
             &Line::Fact(_) => true,
             &Line::Query(_) => true,
@@ -276,7 +276,7 @@ impl Line {
         }
     }
 
-    pub fn enqueue_functors(&self, mut h: usize, functors: &mut Vec<MachineStub>) {
+    pub(crate) fn enqueue_functors(&self, mut h: usize, functors: &mut Vec<MachineStub>) {
         match self {
             &Line::Arithmetic(ref arith_instr) => functors.push(arith_instr.to_functor(h)),
             &Line::Choice(ref choice_instr) => functors.push(choice_instr.to_functor(h)),
@@ -320,7 +320,7 @@ impl Line {
 }
 
 #[inline]
-pub fn to_indexing_line_mut(line: &mut Line) -> Option<&mut Vec<IndexingLine>> {
+pub(crate) fn to_indexing_line_mut(line: &mut Line) -> Option<&mut Vec<IndexingLine>> {
     match line {
         Line::IndexingCode(ref mut indexing_code) => Some(indexing_code),
         _ => None,
@@ -328,7 +328,7 @@ pub fn to_indexing_line_mut(line: &mut Line) -> Option<&mut Vec<IndexingLine>> {
 }
 
 #[inline]
-pub fn to_indexing_line(line: &Line) -> Option<&Vec<IndexingLine>> {
+pub(crate) fn to_indexing_line(line: &Line) -> Option<&Vec<IndexingLine>> {
     match line {
         Line::IndexingCode(ref indexing_code) => Some(indexing_code),
         _ => None,
@@ -336,7 +336,7 @@ pub fn to_indexing_line(line: &Line) -> Option<&Vec<IndexingLine>> {
 }
 
 #[derive(Debug, Clone)]
-pub enum ArithmeticInstruction {
+pub(crate) enum ArithmeticInstruction {
     Add(ArithmeticTerm, ArithmeticTerm, usize),
     Sub(ArithmeticTerm, ArithmeticTerm, usize),
     Mul(ArithmeticTerm, ArithmeticTerm, usize),
@@ -407,7 +407,7 @@ fn arith_instr_bin_functor(
 }
 
 impl ArithmeticInstruction {
-    pub fn to_functor(&self, h: usize) -> MachineStub {
+    pub(crate) fn to_functor(&self, h: usize) -> MachineStub {
         match self {
             &ArithmeticInstruction::Add(ref at_1, ref at_2, t) => {
                 arith_instr_bin_functor(h, "add", at_1, at_2, t)
@@ -505,7 +505,7 @@ impl ArithmeticInstruction {
 }
 
 #[derive(Debug)]
-pub enum ControlInstruction {
+pub(crate) enum ControlInstruction {
     Allocate(usize), // num_frames.
     // name, arity, perm_vars after threshold, last call, use default call policy.
     CallClause(ClauseType, usize, usize, bool, bool),
@@ -518,7 +518,7 @@ pub enum ControlInstruction {
 }
 
 impl ControlInstruction {
-    pub fn perm_vars(&self) -> Option<usize> {
+    pub(crate) fn perm_vars(&self) -> Option<usize> {
         match self {
             ControlInstruction::CallClause(_, _, num_cells, ..) => Some(*num_cells),
             ControlInstruction::JmpBy(_, _, num_cells, ..) => Some(*num_cells),
@@ -526,7 +526,7 @@ impl ControlInstruction {
         }
     }
 
-    pub fn to_functor(&self) -> MachineStub {
+    pub(crate) fn to_functor(&self) -> MachineStub {
         match self {
             &ControlInstruction::Allocate(num_frames) => {
                 functor!("allocate", [integer(num_frames)])
@@ -555,7 +555,7 @@ impl ControlInstruction {
 
 /// `IndexingInstruction` cf. page 110 of wambook.
 #[derive(Debug)]
-pub enum IndexingInstruction {
+pub(crate) enum IndexingInstruction {
     // The first index is the optimal argument being indexed.
     SwitchOnTerm(
         usize,
@@ -569,7 +569,7 @@ pub enum IndexingInstruction {
 }
 
 impl IndexingInstruction {
-    pub fn to_functor(&self, mut h: usize) -> MachineStub {
+    pub(crate) fn to_functor(&self, mut h: usize) -> MachineStub {
         match self {
             &IndexingInstruction::SwitchOnTerm(arg, vars, constants, lists, structures) => {
                 functor!(
@@ -657,7 +657,7 @@ impl IndexingInstruction {
 }
 
 #[derive(Debug, Clone)]
-pub enum FactInstruction {
+pub(crate) enum FactInstruction {
     GetConstant(Level, Constant, RegType),
     GetList(Level, RegType),
     GetPartialString(Level, String, RegType, bool),
@@ -672,7 +672,7 @@ pub enum FactInstruction {
 }
 
 impl FactInstruction {
-    pub fn to_functor(&self, h: usize) -> MachineStub {
+    pub(crate) fn to_functor(&self, h: usize) -> MachineStub {
         match self {
             &FactInstruction::GetConstant(lvl, ref c, r) => {
                 let lvl_stub = lvl.into_functor();
@@ -745,7 +745,7 @@ impl FactInstruction {
 }
 
 #[derive(Debug, Clone)]
-pub enum QueryInstruction {
+pub(crate) enum QueryInstruction {
     GetVariable(RegType, usize),
     PutConstant(Level, Constant, RegType),
     PutList(Level, RegType),
@@ -762,7 +762,7 @@ pub enum QueryInstruction {
 }
 
 impl QueryInstruction {
-    pub fn to_functor(&self, h: usize) -> MachineStub {
+    pub(crate) fn to_functor(&self, h: usize) -> MachineStub {
         match self {
             &QueryInstruction::PutUnsafeValue(norm, arg) => {
                 functor!("put_unsafe_value", [integer(norm), integer(arg)])
@@ -842,6 +842,6 @@ impl QueryInstruction {
     }
 }
 
-pub type CompiledFact = Vec<FactInstruction>;
+pub(crate) type CompiledFact = Vec<FactInstruction>;
 
-pub type Code = Vec<Line>;
+pub(crate) type Code = Vec<Line>;

src/iterators.rs

@@ -13,7 +13,7 @@ use std::rc::Rc;
 use std::vec::Vec;
 
 #[derive(Debug, Clone)]
-pub enum TermRef<'a> {
+pub(crate) enum TermRef<'a> {
     AnonVar(Level),
     Cons(Level, &'a Cell<RegType>, &'a Term, &'a Term),
     Constant(Level, &'a Cell<RegType>, &'a Constant),
@@ -23,7 +23,7 @@ pub enum TermRef<'a> {
 }
 
 impl<'a> TermRef<'a> {
-    pub fn level(self) -> Level {
+    pub(crate) fn level(self) -> Level {
         match self {
             TermRef::AnonVar(lvl)
             | TermRef::Cons(lvl, ..)
@@ -36,7 +36,7 @@ impl<'a> TermRef<'a> {
 }
 
 #[derive(Debug)]
-pub enum TermIterState<'a> {
+pub(crate) enum TermIterState<'a> {
     AnonVar(Level),
     Constant(Level, &'a Cell<RegType>, &'a Constant),
     Clause(
@@ -97,7 +97,7 @@ fn is_partial_string<'a>(head: &'a Term, mut tail: &'a Term) -> Option<(String,
 }
 
 impl<'a> TermIterState<'a> {
-    pub fn subterm_to_state(lvl: Level, term: &'a Term) -> TermIterState<'a> {
+    pub(crate) fn subterm_to_state(lvl: Level, term: &'a Term) -> TermIterState<'a> {
         match term {
             &Term::AnonVar => TermIterState::AnonVar(lvl),
             &Term::Clause(ref cell, ref name, ref subterms, ref spec) => {
@@ -119,7 +119,7 @@ impl<'a> TermIterState<'a> {
 }
 
 #[derive(Debug)]
-pub struct QueryIterator<'a> {
+pub(crate) struct QueryIterator<'a> {
     state_stack: Vec<TermIterState<'a>>,
 }
 
@@ -286,7 +286,7 @@ impl<'a> Iterator for QueryIterator<'a> {
 }
 
 #[derive(Debug)]
-pub struct FactIterator<'a> {
+pub(crate) struct FactIterator<'a> {
     state_queue: VecDeque<TermIterState<'a>>,
     iterable_root: bool,
 }
@@ -297,7 +297,7 @@ impl<'a> FactIterator<'a> {
             .push_back(TermIterState::subterm_to_state(lvl, term));
     }
 
-    pub fn from_rule_head_clause(terms: &'a Vec<Box<Term>>) -> Self {
+    pub(crate) fn from_rule_head_clause(terms: &'a Vec<Box<Term>>) -> Self {
         let state_queue = terms
             .iter()
             .map(|bt| TermIterState::subterm_to_state(Level::Shallow, bt.as_ref()))
@@ -386,26 +386,26 @@ impl<'a> Iterator for FactIterator<'a> {
     }
 }
 
-pub fn post_order_iter(term: &Term) -> QueryIterator {
+pub(crate) fn post_order_iter(term: &Term) -> QueryIterator {
     QueryIterator::from_term(term)
 }
 
-pub fn breadth_first_iter(term: &Term, iterable_root: bool) -> FactIterator {
+pub(crate) fn breadth_first_iter(term: &Term, iterable_root: bool) -> FactIterator {
     FactIterator::new(term, iterable_root)
 }
 
 #[derive(Debug)]
-pub enum ChunkedTerm<'a> {
+pub(crate) enum ChunkedTerm<'a> {
     HeadClause(ClauseName, &'a Vec<Box<Term>>),
     BodyTerm(&'a QueryTerm),
 }
 
-pub fn query_term_post_order_iter<'a>(query_term: &'a QueryTerm) -> QueryIterator<'a> {
+pub(crate) fn query_term_post_order_iter<'a>(query_term: &'a QueryTerm) -> QueryIterator<'a> {
     QueryIterator::new(query_term)
 }
 
 impl<'a> ChunkedTerm<'a> {
-    pub fn post_order_iter(&self) -> QueryIterator<'a> {
+    pub(crate) fn post_order_iter(&self) -> QueryIterator<'a> {
         match self {
             &ChunkedTerm::BodyTerm(ref qt) => QueryIterator::new(qt),
             &ChunkedTerm::HeadClause(_, terms) => QueryIterator::from_rule_head_clause(terms),
@@ -425,8 +425,8 @@ fn contains_cut_var<'a, Iter: Iterator<Item = &'a Term>>(terms: Iter) -> bool {
     false
 }
 
-pub struct ChunkedIterator<'a> {
+pub(crate) struct ChunkedIterator<'a> {
-    pub chunk_num: usize,
+    pub(crate) chunk_num: usize,
     iter: Box<dyn Iterator<Item = ChunkedTerm<'a>> + 'a>,
     deep_cut_encountered: bool,
     cut_var_in_head: bool,
@@ -448,7 +448,7 @@ type ChunkedIteratorItem<'a> = (usize, usize, Vec<ChunkedTerm<'a>>);
 type RuleBodyIteratorItem<'a> = (usize, usize, Vec<&'a QueryTerm>);
 
 impl<'a> ChunkedIterator<'a> {
-    pub fn rule_body_iter(self) -> Box<dyn Iterator<Item = RuleBodyIteratorItem<'a>> + 'a> {
+    pub(crate) fn rule_body_iter(self) -> Box<dyn Iterator<Item = RuleBodyIteratorItem<'a>> + 'a> {
         Box::new(self.filter_map(|(cn, lt_arity, terms)| {
             let filtered_terms: Vec<_> = terms
                 .into_iter()
@@ -466,7 +466,7 @@ impl<'a> ChunkedIterator<'a> {
         }))
     }
     /*
-        pub fn from_term_sequence(terms: &'a [QueryTerm]) -> Self {
+        pub(crate) fn from_term_sequence(terms: &'a [QueryTerm]) -> Self {
             ChunkedIterator {
                 chunk_num: 0,
                 iter: Box::new(terms.iter().map(|t| ChunkedTerm::BodyTerm(t))),
@@ -475,7 +475,7 @@ impl<'a> ChunkedIterator<'a> {
             }
         }
     */
-    pub fn from_rule_body(p1: &'a QueryTerm, clauses: &'a Vec<QueryTerm>) -> Self {
+    pub(crate) 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)));
 
@@ -487,7 +487,7 @@ impl<'a> ChunkedIterator<'a> {
         }
     }
 
-    pub fn from_rule(rule: &'a Rule) -> Self {
+    pub(crate) fn from_rule(rule: &'a Rule) -> Self {
         let &Rule {
             head: (ref name, ref args, ref p1),
             ref clauses,
@@ -505,7 +505,7 @@ impl<'a> ChunkedIterator<'a> {
         }
     }
 
-    pub fn encountered_deep_cut(&self) -> bool {
+    pub(crate) fn encountered_deep_cut(&self) -> bool {
         self.deep_cut_encountered
     }
 

src/lib.rs

@@ -17,29 +17,19 @@ mod heap_print;
 mod indexing;
 mod instructions;
 mod iterators;
-mod machine;
+pub mod machine;
-mod read;
+pub mod read;
 mod targets;
 mod write;
 
-use machine::streams::*;
 use machine::*;
-use read::*;
 
 use nix::sys::signal;
 use std::sync::atomic::Ordering;
 
-extern "C" fn handle_sigint(signal: libc::c_int) {
+pub 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);
     }
 }
-
-fn main() {
-    let handler = signal::SigHandler::Handler(handle_sigint);
-    unsafe { signal::signal(signal::Signal::SIGINT, handler) }.unwrap();
-
-    let mut wam = Machine::new(readline::input_stream(), Stream::stdout());
-    wam.run_top_level();
-}

src/machine/code_repo.rs

@@ -3,58 +3,44 @@ use crate::instructions::*;
 use crate::machine::machine_indices::*;
 
 #[derive(Debug)]
-pub struct CodeRepo {
+pub(crate) struct CodeRepo {
     pub(super) code: Code,
 }
 
 impl CodeRepo {
     #[inline]
-    pub(super)
+    pub(super) fn new() -> Self {
-    fn new() -> Self {
+        CodeRepo { code: Code::new() }
-        CodeRepo {
-            code: Code::new(),
-        }
     }
 
     #[inline]
-    pub(super)
+    pub(super) fn lookup_local_instr<'a>(&'a self, p: LocalCodePtr) -> RefOrOwned<'a, Line> {
-    fn lookup_local_instr<'a>(
-        &'a self,
-        p: LocalCodePtr,
-    ) -> RefOrOwned<'a, Line> {
         match p {
             LocalCodePtr::Halt => {
                 // exit with the interrupt exit code.
                 std::process::exit(1);
             }
-            LocalCodePtr::DirEntry(p) => {
+            LocalCodePtr::DirEntry(p) => RefOrOwned::Borrowed(&self.code[p as usize]),
-                RefOrOwned::Borrowed(&self.code[p as usize])
+            LocalCodePtr::IndexingBuf(p, o, i) => match &self.code[p] {
-            }
+                &Line::IndexingCode(ref indexing_lines) => match &indexing_lines[o] {
-            LocalCodePtr::IndexingBuf(p, o, i) => {
+                    &IndexingLine::IndexedChoice(ref indexed_choice_instrs) => {
-                match &self.code[p] {
+                        RefOrOwned::Owned(Line::IndexedChoice(indexed_choice_instrs[i]))
-                    &Line::IndexingCode(ref indexing_lines) => {
+                    }
-                        match &indexing_lines[o] {
+                    &IndexingLine::DynamicIndexedChoice(ref indexed_choice_instrs) => {
-                            &IndexingLine::IndexedChoice(ref indexed_choice_instrs) => {
+                        RefOrOwned::Owned(Line::DynamicIndexedChoice(indexed_choice_instrs[i]))
-                                RefOrOwned::Owned(Line::IndexedChoice(indexed_choice_instrs[i]))
-                            }
-                            &IndexingLine::DynamicIndexedChoice(ref indexed_choice_instrs) => {
-                                RefOrOwned::Owned(Line::DynamicIndexedChoice(indexed_choice_instrs[i]))
-                            }
-                            _ => {
-                                unreachable!()
-                            }
-                        }
                     }
                     _ => {
                         unreachable!()
                     }
+                },
+                _ => {
+                    unreachable!()
                 }
-            }
+            },
         }
     }
 
-    pub(super)
+    pub(super) fn lookup_instr<'a>(
-    fn lookup_instr<'a>(
         &'a self,
         last_call: bool,
         p: &CodePtr,
@@ -63,9 +49,7 @@ impl CodeRepo {
             &CodePtr::Local(local) => {
                 return Some(self.lookup_local_instr(local));
             }
-            &CodePtr::REPL(..) => {
+            &CodePtr::REPL(..) => None,
-                None
-            }
             &CodePtr::BuiltInClause(ref built_in, _) => {
                 let call_clause = call_clause!(
                     ClauseType::BuiltIn(built_in.clone()),
@@ -77,26 +61,26 @@ impl CodeRepo {
                 Some(RefOrOwned::Owned(call_clause))
             }
             &CodePtr::CallN(arity, _, last_call) => {
-                let call_clause = call_clause!(
+                let call_clause = call_clause!(ClauseType::CallN, arity, 0, last_call);
-                    ClauseType::CallN,
-                    arity,
-                    0,
-                    last_call
-                );
 
                 Some(RefOrOwned::Owned(call_clause))
             }
-            &CodePtr::VerifyAttrInterrupt(p) => {
+            &CodePtr::VerifyAttrInterrupt(p) => Some(RefOrOwned::Borrowed(&self.code[p])),
-                Some(RefOrOwned::Borrowed(&self.code[p]))
-            }
         }
     }
 
-    pub(super)
+    pub(super) fn find_living_dynamic_else(
-    fn find_living_dynamic_else(&self, mut p: usize, cc: usize) -> Option<(usize, usize)> {
+        &self,
+        mut p: usize,
+        cc: usize,
+    ) -> Option<(usize, usize)> {
         loop {
             match &self.code[p] {
-                &Line::Choice(ChoiceInstruction::DynamicElse(birth, death, NextOrFail::Next(i))) => {
+                &Line::Choice(ChoiceInstruction::DynamicElse(
+                    birth,
+                    death,
+                    NextOrFail::Next(i),
+                )) => {
                     if birth < cc && Death::Finite(cc) <= death {
                         return Some((p, i));
                     } else if i > 0 {
@@ -105,7 +89,11 @@ impl CodeRepo {
                         return None;
                     }
                 }
-                &Line::Choice(ChoiceInstruction::DynamicElse(birth, death, NextOrFail::Fail(_))) => {
+                &Line::Choice(ChoiceInstruction::DynamicElse(
+                    birth,
+                    death,
+                    NextOrFail::Fail(_),
+                )) => {
                     if birth < cc && Death::Finite(cc) <= death {
                         return Some((p, 0));
                     } else {
@@ -128,8 +116,8 @@ impl CodeRepo {
                 &Line::Choice(ChoiceInstruction::DynamicInternalElse(
                     birth,
                     death,
-                    NextOrFail::Fail(_)),
+                    NextOrFail::Fail(_),
-                ) => {
+                )) => {
                     if birth < cc && Death::Finite(cc) <= death {
                         return Some((p, 0));
                     } else {
@@ -146,8 +134,11 @@ impl CodeRepo {
         }
     }
 
-    pub(super)
+    pub(super) fn find_living_dynamic(
-    fn find_living_dynamic(&self, p: LocalCodePtr, cc: usize) -> Option<(usize, usize, usize, bool)> {
+        &self,
+        p: LocalCodePtr,
+        cc: usize,
+    ) -> Option<(usize, usize, usize, bool)> {
         let (p, oi, mut ii) = match p {
             LocalCodePtr::IndexingBuf(p, oi, ii) => (p, oi, ii),
             _ => unreachable!(),
@@ -158,27 +149,27 @@ impl CodeRepo {
                 IndexingLine::DynamicIndexedChoice(ref indexed_choice_instrs) => {
                     indexed_choice_instrs
                 }
-                _ => unreachable!()
+                _ => unreachable!(),
-            }
+            },
-            _ => unreachable!()
+            _ => unreachable!(),
         };
 
         loop {
             match &indexed_choice_instrs.get(ii) {
-                Some(&offset) => {
+                Some(&offset) => match &self.code[p + offset - 1] {
-                    match &self.code[p + offset - 1] {
+                    &Line::Choice(ChoiceInstruction::DynamicInternalElse(
-                        &Line::Choice(ChoiceInstruction::DynamicInternalElse(
+                        birth,
-                            birth, death, next_or_fail,
+                        death,
-                        )) => {
+                        next_or_fail,
-                            if birth < cc && Death::Finite(cc) <= death {
+                    )) => {
-                                return Some((offset, oi, ii, next_or_fail.is_next()));
+                        if birth < cc && Death::Finite(cc) <= death {
-                            } else {
+                            return Some((offset, oi, ii, next_or_fail.is_next()));
-                                ii += 1;
+                        } else {
-                            }
+                            ii += 1;
                         }
-                        _ => unreachable!(),
                     }
-                }
+                    _ => unreachable!(),
+                },
                 None => return None,
             }
         }

src/machine/code_walker.rs

@@ -7,8 +7,10 @@ fn capture_offset(line: &Line, index: usize, stack: &mut Vec<usize>) -> bool {
         &Line::Choice(ChoiceInstruction::TryMeElse(offset)) if offset > 0 => {
             stack.push(index + offset);
         }
-        &Line::Choice(ChoiceInstruction::DefaultRetryMeElse(offset)) |
+        &Line::Choice(ChoiceInstruction::DefaultRetryMeElse(offset))
-        &Line::Choice(ChoiceInstruction::RetryMeElse(offset)) if offset > 0 => {
+        | &Line::Choice(ChoiceInstruction::RetryMeElse(offset))
+            if offset > 0 =>
+        {
             stack.push(index + offset);
         }
         &Line::Choice(ChoiceInstruction::DynamicElse(_, _, NextOrFail::Next(offset)))
@@ -26,8 +28,8 @@ fn capture_offset(line: &Line, index: usize, stack: &mut Vec<usize>) -> bool {
             stack.push(index + offset);
             return true;
         }
-        &Line::Control(ControlInstruction::Proceed) |
+        &Line::Control(ControlInstruction::Proceed)
-        &Line::Control(ControlInstruction::CallClause(_, _, _, true, _)) => {
+        | &Line::Control(ControlInstruction::CallClause(_, _, _, true, _)) => {
             return true;
         }
         &Line::Control(ControlInstruction::RevJmpBy(offset)) => {
@@ -37,8 +39,7 @@ fn capture_offset(line: &Line, index: usize, stack: &mut Vec<usize>) -> bool {
                 return true;
             }
         }
-        _ => {
+        _ => {}
-        }
     };
 
     false
@@ -48,8 +49,7 @@ fn capture_offset(line: &Line, index: usize, stack: &mut Vec<usize>) -> bool {
  * begin in code at the offset p. Each instruction is passed to the
  * walker function.
  */
-pub fn walk_code(code: &Code, p: usize, mut walker: impl FnMut(&Line))
+pub(crate) fn walk_code(code: &Code, p: usize, mut walker: impl FnMut(&Line)) {
-{
     let mut stack = vec![p];
     let mut visited_indices = IndexSet::new();
 
@@ -60,7 +60,7 @@ pub fn walk_code(code: &Code, p: usize, mut walker: impl FnMut(&Line))
             visited_indices.insert(first_index);
         }
 
-        for (index, instr) in code[first_index ..].iter().enumerate() {
+        for (index, instr) in code[first_index..].iter().enumerate() {
             walker(instr);
 
             if capture_offset(instr, first_index + index, &mut stack) {
@@ -74,7 +74,7 @@ pub fn walk_code(code: &Code, p: usize, mut walker: impl FnMut(&Line))
  * the code. Otherwise identical to walk_code.
  */
 /*
-pub fn walk_code_mut(code: &mut Code, p: usize, mut walker: impl FnMut(&mut Line))
+pub(crate) fn walk_code_mut(code: &mut Code, p: usize, mut walker: impl FnMut(&mut Line))
 {
     let mut queue = VecDeque::from(vec![p]);
 

src/machine/copier.rs

@@ -7,13 +7,12 @@ use std::ops::IndexMut;
 type Trail = Vec<(Ref, HeapCellValue)>;
 
 #[derive(Debug, Clone, Copy)]
-pub enum AttrVarPolicy {
+pub(crate) enum AttrVarPolicy {
     DeepCopy,
-    StripAttributes
+    StripAttributes,
 }
 
-pub(crate)
+pub(crate) trait CopierTarget: IndexMut<usize, Output = HeapCellValue> {
-trait CopierTarget: IndexMut<usize, Output = HeapCellValue> {
     fn deref(&self, val: Addr) -> Addr;
     fn push(&mut self, val: HeapCellValue);
     fn stack(&mut self) -> &mut Stack;
@@ -21,8 +20,7 @@ trait CopierTarget: IndexMut<usize, Output = HeapCellValue> {
     fn threshold(&self) -> usize;
 }
 
-pub(crate)
+pub(crate) fn copy_term<T: CopierTarget>(target: T, addr: Addr, attr_var_policy: AttrVarPolicy) {
-fn copy_term<T: CopierTarget>(target: T, addr: Addr, attr_var_policy: AttrVarPolicy) {
     let mut copy_term_state = CopyTermState::new(target, attr_var_policy);
     copy_term_state.copy_term_impl(addr);
 }
@@ -43,7 +41,7 @@ impl<T: CopierTarget> CopyTermState<T> {
             scan: 0,
             old_h: target.threshold(),
             target,
-            attr_var_policy
+            attr_var_policy,
         }
     }
 
@@ -59,14 +57,11 @@ impl<T: CopierTarget> CopyTermState<T> {
             HeapCellValue::Addr(Addr::Lis(threshold)),
         );
 
-        self.trail.push((
+        self.trail.push((Ref::HeapCell(addr), trail_item));
-            Ref::HeapCell(addr),
-            trail_item,
-        ));
     }
 
     fn copy_list(&mut self, addr: usize) {
-        for offset in 0 .. 2 {
+        for offset in 0..2 {
             if let Addr::Lis(h) = self.target[addr + offset].as_addr(addr + offset) {
                 if h >= self.old_h {
                     *self.value_at_scan() = HeapCellValue::Addr(Addr::Lis(h));
@@ -81,12 +76,14 @@ impl<T: CopierTarget> CopyTermState<T> {
 
         *self.value_at_scan() = HeapCellValue::Addr(Addr::Lis(threshold));
 
-        for i in 0 .. 2 {
+        for i in 0..2 {
             let hcv = self.target[addr + i].context_free_clone();
             self.target.push(hcv);
         }
 
-        let cdr = self.target.store(self.target.deref(Addr::HeapCell(addr + 1)));
+        let cdr = self
+            .target
+            .store(self.target.deref(Addr::HeapCell(addr + 1)));
 
         if !cdr.is_ref() {
             self.trail_list_cell(addr + 1, threshold);
@@ -113,34 +110,27 @@ impl<T: CopierTarget> CopyTermState<T> {
 
         let threshold = self.target.threshold();
 
-        *self.value_at_scan() =
+        *self.value_at_scan() = HeapCellValue::Addr(Addr::PStrLocation(threshold, n));
-            HeapCellValue::Addr(Addr::PStrLocation(threshold, n));
 
         self.scan += 1;
 
-        let (pstr, has_tail) =
+        let (pstr, has_tail) = match &self.target[addr] {
-            match &self.target[addr] {
+            &HeapCellValue::PartialString(ref pstr, has_tail) => {
-                &HeapCellValue::PartialString(ref pstr, has_tail) => {
+                (pstr.clone_from_offset(0), has_tail)
-                    (pstr.clone_from_offset(0), has_tail)
+            }
-                }
+            _ => {
-                _ => {
+                unreachable!()
-                    unreachable!()
+            }
-                }
+        };
-            };
 
-        self.target.push(HeapCellValue::PartialString(pstr, has_tail));
+        self.target
+            .push(HeapCellValue::PartialString(pstr, has_tail));
 
         let replacement = HeapCellValue::Addr(Addr::PStrLocation(threshold, n));
 
-        let trail_item = mem::replace(
+        let trail_item = mem::replace(&mut self.target[addr], replacement);
-            &mut self.target[addr],
-            replacement,
-        );
 
-        self.trail.push((
+        self.trail.push((Ref::HeapCell(addr), trail_item));
-            Ref::HeapCell(addr),
-            trail_item,
-        ));
 
         if has_tail {
             let tail_addr = self.target[addr + 1].as_addr(addr + 1);
@@ -154,10 +144,8 @@ impl<T: CopierTarget> CopyTermState<T> {
                 self.target[frontier] = HeapCellValue::Addr(Addr::HeapCell(frontier));
                 self.target[h] = HeapCellValue::Addr(Addr::HeapCell(frontier));
 
-                self.trail.push((
+                self.trail
-                    Ref::HeapCell(h),
+                    .push((Ref::HeapCell(h), HeapCellValue::Addr(Addr::HeapCell(h))));
-                    HeapCellValue::Addr(Addr::HeapCell(h)),
-                ));
             }
             Addr::StackCell(fr, sc) => {
                 self.target[frontier] = HeapCellValue::Addr(Addr::HeapCell(frontier));
@@ -178,13 +166,12 @@ impl<T: CopierTarget> CopyTermState<T> {
                 self.target[frontier] = HeapCellValue::Addr(Addr::HeapCell(threshold));
                 self.target[h] = HeapCellValue::Addr(Addr::HeapCell(threshold));
 
-                self.trail.push((
+                self.trail
-                    Ref::AttrVar(h),
+                    .push((Ref::AttrVar(h), HeapCellValue::Addr(Addr::AttrVar(h))));
-                    HeapCellValue::Addr(Addr::AttrVar(h)),
-                ));
 
                 if let AttrVarPolicy::DeepCopy = self.attr_var_policy {
-                    self.target.push(HeapCellValue::Addr(Addr::AttrVar(threshold)));
+                    self.target
+                        .push(HeapCellValue::Addr(Addr::AttrVar(threshold)));
 
                     let list_val = self.target[h + 1].context_free_clone();
                     self.target.push(list_val);
@@ -226,12 +213,10 @@ impl<T: CopierTarget> CopyTermState<T> {
                     HeapCellValue::Addr(Addr::Str(threshold)),
                 );
 
-                self.trail.push((
+                self.trail.push((Ref::HeapCell(addr), trail_item));
-                    Ref::HeapCell(addr),
-                    trail_item,
-                ));
 
-                self.target.push(HeapCellValue::NamedStr(arity, name, fixity));
+                self.target
+                    .push(HeapCellValue::NamedStr(arity, name, fixity));
 
                 for i in 0..arity {
                     let hcv = self.target[addr + 1 + i].context_free_clone();
@@ -255,43 +240,41 @@ impl<T: CopierTarget> CopyTermState<T> {
 
         while self.scan < self.target.threshold() {
             match self.value_at_scan() {
-                &mut HeapCellValue::Addr(addr) => {
+                &mut HeapCellValue::Addr(addr) => match addr {
-                    match addr {
+                    Addr::Con(h) => {
-                        Addr::Con(h) => {
+                        let addr = self.target[h].as_addr(h);
-                            let addr = self.target[h].as_addr(h);
 
-                            if addr == Addr::Con(h) {
+                        if addr == Addr::Con(h) {
-                                *self.value_at_scan() = self.target[h].context_free_clone();
-                            } else {
-                                *self.value_at_scan() = HeapCellValue::Addr(addr);
-                            }
-                        }
-                        Addr::Lis(h) => {
-                            if h >= self.old_h {
-                                self.scan += 1;
-                            } else {
-                                self.copy_list(h);
-                            }
-                        }
-                        addr @ Addr::AttrVar(_) |
-                        addr @ Addr::HeapCell(_) |
-                        addr @ Addr::StackCell(..) => {
-                            self.copy_var(addr);
-                        }
-                        Addr::Str(addr) => {
-                            self.copy_structure(addr);
-                        }
-                        Addr::PStrLocation(addr, n) => {
-                            self.copy_partial_string(addr, n);
-                        }
-                        Addr::Stream(h) => {
                             *self.value_at_scan() = self.target[h].context_free_clone();
-                        }
+                        } else {
-                        _ => {
+                            *self.value_at_scan() = HeapCellValue::Addr(addr);
-                            self.scan += 1;
                         }
                     }
-                }
+                    Addr::Lis(h) => {
+                        if h >= self.old_h {
+                            self.scan += 1;
+                        } else {
+                            self.copy_list(h);
+                        }
+                    }
+                    addr @ Addr::AttrVar(_)
+                    | addr @ Addr::HeapCell(_)
+                    | addr @ Addr::StackCell(..) => {
+                        self.copy_var(addr);
+                    }
+                    Addr::Str(addr) => {
+                        self.copy_structure(addr);
+                    }
+                    Addr::PStrLocation(addr, n) => {
+                        self.copy_partial_string(addr, n);
+                    }
+                    Addr::Stream(h) => {
+                        *self.value_at_scan() = self.target[h].context_free_clone();
+                    }
+                    _ => {
+                        self.scan += 1;
+                    }
+                },
                 _ => {
                     self.scan += 1;
                 }
@@ -304,10 +287,10 @@ impl<T: CopierTarget> CopyTermState<T> {
     fn unwind_trail(&mut self) {
         for (r, value) in self.trail.drain(0..) {
             match r {
-                Ref::AttrVar(h) | Ref::HeapCell(h) =>
+                Ref::AttrVar(h) | Ref::HeapCell(h) => self.target[h] = value,
-                    self.target[h] = value,
+                Ref::StackCell(fr, sc) => {
-                Ref::StackCell(fr, sc) =>
+                    self.target.stack().index_and_frame_mut(fr)[sc] = value.as_addr(0)
-                    self.target.stack().index_and_frame_mut(fr)[sc] = value.as_addr(0),
+                }
             }
         }
     }

src/machine/heap.rs

@@ -429,7 +429,7 @@ impl<T: RawBlockTraits> HeapTemplate<T> {
     }
 
     #[inline]
-    pub fn index_addr<'a>(&'a self, addr: &Addr) -> RefOrOwned<'a, HeapCellValue> {
+    pub(crate) fn index_addr<'a>(&'a self, addr: &Addr) -> RefOrOwned<'a, HeapCellValue> {
         match addr {
             &Addr::Con(h) | &Addr::Str(h) | &Addr::Stream(h) | &Addr::TcpListener(h) => {
                 RefOrOwned::Borrowed(&self[h])

src/machine/loader.rs

@@ -184,18 +184,16 @@ impl<'a> Drop for LoadState<'a> {
                     module_decl,
                     listing_src,
                     local_extensible_predicates,
-                ) => {
+                ) => match self.wam.indices.modules.get_mut(&module_decl.name) {
-                    match self.wam.indices.modules.get_mut(&module_decl.name) {
+                    Some(ref mut module) => {
-                        Some(ref mut module) => {
+                        module.module_decl = module_decl;
-                            module.module_decl = module_decl;
+                        module.listing_src = listing_src;
-                            module.listing_src = listing_src;
+                        module.local_extensible_predicates = local_extensible_predicates;
-                            module.local_extensible_predicates = local_extensible_predicates;
-                        }
-                        _ => {
-                            unreachable!()
-                        }
                     }
-                }
+                    _ => {
+                        unreachable!()
+                    }
+                },
                 RetractionRecord::AddedDiscontiguousPredicate(compilation_target, key) => {
                     match compilation_target {
                         CompilationTarget::User => {
@@ -487,17 +485,15 @@ impl<'a> Drop for LoadState<'a> {
                     }
                 }
                 RetractionRecord::SkeletonLocalClauseClausePopFront(
-                    src_compilation_target, local_compilation_target, key,
+                    src_compilation_target,
+                    local_compilation_target,
+                    key,
                 ) => {
-                    match self
+                    match self.wam.indices.get_local_predicate_skeleton_mut(
-                        .wam
+                        &src_compilation_target,
-                        .indices
+                        local_compilation_target,
-                        .get_local_predicate_skeleton_mut(
+                        key,
-                            &src_compilation_target,
+                    ) {
-                            local_compilation_target,
-                            key,
-                        )
-                    {
                         Some(skeleton) => {
                             skeleton.clause_clause_locs.pop_front();
                         }
@@ -505,17 +501,15 @@ impl<'a> Drop for LoadState<'a> {
                     }
                 }
                 RetractionRecord::SkeletonLocalClauseClausePopBack(
-                    src_compilation_target, local_compilation_target, key,
+                    src_compilation_target,
+                    local_compilation_target,
+                    key,
                 ) => {
-                    match self
+                    match self.wam.indices.get_local_predicate_skeleton_mut(
-                        .wam
+                        &src_compilation_target,
-                        .indices
+                        local_compilation_target,
-                        .get_local_predicate_skeleton_mut(
+                        key,
-                            &src_compilation_target,
+                    ) {
-                            local_compilation_target,
-                            key,
-                        )
-                    {
                         Some(skeleton) => {
                             skeleton.clause_clause_locs.pop_back();
                         }
@@ -528,15 +522,11 @@ impl<'a> Drop for LoadState<'a> {
                     key,
                     len,
                 ) => {
-                    match self
+                    match self.wam.indices.get_local_predicate_skeleton_mut(
-                        .wam
+                        &src_compilation_target,
-                        .indices
+                        local_compilation_target,
-                        .get_local_predicate_skeleton_mut(
+                        key,
-                            &src_compilation_target,
+                    ) {
-                            local_compilation_target,
-                            key,
-                        )
-                    {
                         Some(skeleton) => {
                             skeleton.clause_clause_locs.truncate_back(len);
                         }
@@ -603,15 +593,11 @@ impl<'a> Drop for LoadState<'a> {
                     key,
                     clause_locs,
                 ) => {
-                    match self
+                    match self.wam.indices.get_local_predicate_skeleton_mut(
-                        .wam
+                        &compilation_target,
-                        .indices
+                        local_compilation_target,
-                        .get_local_predicate_skeleton_mut(
+                        key,
-                            &compilation_target,
+                    ) {
-                            local_compilation_target,
-                            key,
-                        )
-                    {
                         Some(skeleton) => skeleton.clause_clause_locs = clause_locs,
                         None => {}
                     }
@@ -663,7 +649,7 @@ impl<'a> Drop for LoadState<'a> {
 }
 
 #[derive(Debug, Clone, Hash, PartialEq, Eq)]
-pub enum CompilationTarget {
+pub(crate) enum CompilationTarget {
     Module(ClauseName),
     User,
 }
@@ -682,7 +668,7 @@ impl CompilationTarget {
     }
 
     #[inline]
-    pub fn module_name(&self) -> ClauseName {
+    pub(crate) fn module_name(&self) -> ClauseName {
         match self {
             CompilationTarget::User => {
                 clause_name!("user")
@@ -692,7 +678,7 @@ impl CompilationTarget {
     }
 }
 
-pub struct PredicateQueue {
+pub(crate) struct PredicateQueue {
     pub(super) predicates: Vec<Term>,
     pub(super) compilation_target: CompilationTarget,
 }
@@ -781,10 +767,9 @@ impl<'a, TS: TermStream> Loader<'a, TS> {
             }
 
             let term = match term {
-                Term::Clause(_, name, terms, _)
+                Term::Clause(_, name, terms, _) if name.as_str() == ":-" && terms.len() == 1 => {
-                    if name.as_str() == ":-" && terms.len() == 1 => {
+                    return Ok(Some(setup_declaration(&self.load_state, terms)?));
-                        return Ok(Some(setup_declaration(&self.load_state, terms)?));
+                }
-                    },
                 term => term,
             };
 
@@ -808,8 +793,7 @@ impl<'a, TS: TermStream> Loader<'a, TS> {
                 self.load_state.compilation_target =
                     CompilationTarget::Module(module_decl.name.clone());
 
-                self.predicates.compilation_target =
+                self.predicates.compilation_target = self.load_state.compilation_target.clone();
-                    self.load_state.compilation_target.clone();
 
                 self.load_state
                     .add_module(module_decl, self.term_stream.listing_src().clone());
@@ -975,9 +959,10 @@ impl<'a, TS: TermStream> Loader<'a, TS> {
                         if !*flag_accessor(skeleton) {
                             *flag_accessor(skeleton) = true;
 
-                            self.load_state.retraction_info.push_record(
+                            self.load_state.retraction_info.push_record(retraction_fn(
-                                retraction_fn(compilation_target.clone(), key.clone()),
+                                compilation_target.clone(),
-                            );
+                                key.clone(),
+                            ));
                         }
                     }
                     None => {
@@ -1003,9 +988,10 @@ impl<'a, TS: TermStream> Loader<'a, TS> {
                             if !*flag_accessor(skeleton) {
                                 *flag_accessor(skeleton) = true;
 
-                                self.load_state.retraction_info.push_record(
+                                self.load_state.retraction_info.push_record(retraction_fn(
-                                    retraction_fn(compilation_target.clone(), key.clone()),
+                                    compilation_target.clone(),
-                                );
+                                    key.clone(),
+                                ));
                             }
                         }
                         None => {
@@ -1024,7 +1010,8 @@ impl<'a, TS: TermStream> Loader<'a, TS> {
                         }
                     },
                     None => {
-                        self.load_state.add_dynamically_generated_module(module_name);
+                        self.load_state
+                            .add_dynamically_generated_module(module_name);
 
                         let mut skeleton = PredicateSkeleton::new();
                         *flag_accessor(&mut skeleton) = true;
@@ -1068,28 +1055,29 @@ impl<'a, TS: TermStream> Loader<'a, TS> {
                 }
                 CompilationTarget::Module(ref module_name) => {
                     match self.load_state.wam.indices.modules.get_mut(module_name) {
-                        Some(ref mut module) =>
+                        Some(ref mut module) => match module
-                            match module.local_extensible_predicates.get_mut(
+                            .local_extensible_predicates
-                                &(compilation_target.clone(), key.clone()),
+                            .get_mut(&(compilation_target.clone(), key.clone()))
-                            ) {
+                        {
-                                Some(ref mut skeleton) => {
+                            Some(ref mut skeleton) => {
-                                    if !*flag_accessor(skeleton) {
+                                if !*flag_accessor(skeleton) {
-                                        *flag_accessor(skeleton) = true;
+                                    *flag_accessor(skeleton) = true;
-                                    }
                                 }
-                                None => {
+                            }
-                                    let mut skeleton = PredicateSkeleton::new();
+                            None => {
-                                    *flag_accessor(&mut skeleton) = true;
+                                let mut skeleton = PredicateSkeleton::new();
+                                *flag_accessor(&mut skeleton) = true;
 
-                                    self.load_state.add_local_extensible_predicate(
+                                self.load_state.add_local_extensible_predicate(
-                                        compilation_target.clone(),
+                                    compilation_target.clone(),
-                                        key.clone(),
+                                    key.clone(),
-                                        skeleton,
+                                    skeleton,
-                                    );
+                                );
-                                }
+                            }
-                            },
+                        },
                         None => {
-                            self.load_state.add_dynamically_generated_module(module_name);
+                            self.load_state
+                                .add_dynamically_generated_module(module_name);
 
                             let mut skeleton = PredicateSkeleton::new();
                             *flag_accessor(&mut skeleton) = true;
@@ -1106,7 +1094,10 @@ impl<'a, TS: TermStream> Loader<'a, TS> {
 
             Ok(())
         } else {
-            Err(SessionError::PredicateNotMultifileOrDiscontiguous(compilation_target, key))
+            Err(SessionError::PredicateNotMultifileOrDiscontiguous(
+                compilation_target,
+                key,
+            ))
         }
     }
 
@@ -1139,10 +1130,9 @@ impl<'a, TS: TermStream> Loader<'a, TS> {
             RetractionRecord::AddedDynamicPredicate,
         )?;
 
-        let code_index = self.load_state.get_or_insert_code_index(
+        let code_index = self
-            (name.clone(), arity),
+            .load_state
-            compilation_target.clone(),
+            .get_or_insert_code_index((name.clone(), arity), compilation_target.clone());
-        );
 
         if let IndexPtr::Undefined = code_index.get() {
             set_code_index(
@@ -1204,12 +1194,11 @@ impl<'a, TS: TermStream> Loader<'a, TS> {
                 &self.load_state.compilation_target,
                 self.predicates.compilation_target.clone(),
                 key.clone(),
-            )
+            ) {
-        {
+            Some(skeleton) if !skeleton.clause_clause_locs.is_empty() => {
-            Some(skeleton) if !skeleton.clause_clause_locs.is_empty() =>
+                mem::replace(&mut skeleton.clause_clause_locs, sdeq![])
-                mem::replace(&mut skeleton.clause_clause_locs, sdeq![]),
+            }
-            _ =>
+            _ => return,
-                return,
         };
 
         self.load_state.retraction_info.push_record(
@@ -1233,10 +1222,8 @@ impl<'a, TS: TermStream> Loader<'a, TS> {
                 module_name => module_name.clone(),
             };
 
-            self.load_state.retract_local_clause_clauses(
+            self.load_state
-                clause_clause_compilation_target,
+                .retract_local_clause_clauses(clause_clause_compilation_target, &clause_locs);
-                &clause_locs,
-            );
         }
     }
 }
@@ -1305,7 +1292,9 @@ impl Machine {
                 if export_list.is_empty() {
                     loader.load_state.import_module(library)?;
                 } else {
-                    loader.load_state.import_qualified_module(library, export_list)?;
+                    loader
+                        .load_state
+                        .import_qualified_module(library, export_list)?;
                 }
 
                 LiveTermStream::evacuate(loader)
@@ -1347,29 +1336,39 @@ impl Machine {
 
     #[inline]
     pub(crate) fn add_discontiguous_predicate(&mut self) {
-        self.add_extensible_predicate_declaration(|loader, compilation_target, clause_name, arity| {
+        self.add_extensible_predicate_declaration(
-            loader.add_discontiguous_predicate(compilation_target, clause_name, arity)
+            |loader, compilation_target, clause_name, arity| {
-        });
+                loader.add_discontiguous_predicate(compilation_target, clause_name, arity)
+            },
+        );
     }
 
     #[inline]
     pub(crate) fn add_dynamic_predicate(&mut self) {
-        self.add_extensible_predicate_declaration(|loader, compilation_target, clause_name, arity| {
+        self.add_extensible_predicate_declaration(
-            loader.add_dynamic_predicate(compilation_target, clause_name, arity)
+            |loader, compilation_target, clause_name, arity| {
-        });
+                loader.add_dynamic_predicate(compilation_target, clause_name, arity)
+            },
+        );
     }
 
     #[inline]
     pub(crate) fn add_multifile_predicate(&mut self) {
-        self.add_extensible_predicate_declaration(|loader, compilation_target, clause_name, arity| {
+        self.add_extensible_predicate_declaration(
-            loader.add_multifile_predicate(compilation_target, clause_name, arity)
+            |loader, compilation_target, clause_name, arity| {
-        });
+                loader.add_multifile_predicate(compilation_target, clause_name, arity)
+            },
+        );
     }
 
     fn add_extensible_predicate_declaration(
         &mut self,
-        decl_adder: impl Fn(&mut Loader<LiveTermStream>, CompilationTarget, ClauseName, usize)
+        decl_adder: impl Fn(
-                            -> Result<(), SessionError>,
+            &mut Loader<LiveTermStream>,
+            CompilationTarget,
+            ClauseName,
+            usize,
+        ) -> Result<(), SessionError>,
     ) {
         let module_name = atom_from!(
             self.machine_st,
@@ -1805,15 +1804,10 @@ impl Machine {
             let mut loader = Loader::new(LiveTermStream::new(ListingSource::User), self);
             loader.load_state.compilation_target = compilation_target;
 
-            let clause_clause_compilation_target =
+            let clause_clause_compilation_target = match &loader.load_state.compilation_target {
-                match &loader.load_state.compilation_target {
+                CompilationTarget::User => CompilationTarget::Module(clause_name!("builtins")),
-                    CompilationTarget::User => {
+                module => module.clone(),
-                        CompilationTarget::Module(clause_name!("builtins"))
+            };
-                    }
-                    module => {
-                        module.clone()
-                    }
-                };
 
             let mut clause_clause_target_poses: Vec<_> = loader
                 .load_state
@@ -1830,12 +1824,13 @@ impl Machine {
                             &(clause_name!("$clause"), 2),
                         )
                         .map(|clause_clause_skeleton| {
-                            skeleton.clause_clause_locs
+                            skeleton
+                                .clause_clause_locs
                                 .iter()
                                 .map(|clause_clause_loc| {
-                                    clause_clause_skeleton.target_pos_of_clause_clause_loc(
+                                    clause_clause_skeleton
-                                        *clause_clause_loc,
+                                        .target_pos_of_clause_clause_loc(*clause_clause_loc)
-                                    ).unwrap()
+                                        .unwrap()
                                 })
                                 .collect()
                         })
@@ -1850,17 +1845,18 @@ impl Machine {
                 .get_predicate_skeleton_mut(&loader.load_state.compilation_target, &key)
                 .map(|skeleton| skeleton.reset());
 
-            let code_index = loader.load_state.get_or_insert_code_index(
+            let code_index = loader
-                key,
+                .load_state
-                loader.load_state.compilation_target.clone(),
+                .get_or_insert_code_index(key, loader.load_state.compilation_target.clone());
-            );
 
             code_index.set(IndexPtr::DynamicUndefined);
 
             loader.load_state.compilation_target = clause_clause_compilation_target;
 
             while let Some(target_pos) = clause_clause_target_poses.pop() {
-                loader.load_state.retract_clause((clause_name!("$clause"), 2), target_pos);
+                loader
+                    .load_state
+                    .retract_clause((clause_name!("$clause"), 2), target_pos);
             }
 
             LiveTermStream::evacuate(loader)
@@ -1918,11 +1914,9 @@ impl Machine {
                 &clause_clause_compilation_target,
                 &(clause_name!("$clause"), 2),
             ) {
-                Some(skeleton) => {
+                Some(skeleton) => skeleton
-                    skeleton.target_pos_of_clause_clause_loc(
+                    .target_pos_of_clause_clause_loc(clause_clause_loc)
-                        clause_clause_loc,
+                    .unwrap(),
-                    ).unwrap()
-                }
                 None => {
                     unreachable!();
                 }
@@ -1962,10 +1956,9 @@ impl Machine {
 
         let (loader, evacuable_h) = self.loader_from_heap_evacuable(temp_v!(4));
 
-        loader.load_state.wam.machine_st.fail =
+        loader.load_state.wam.machine_st.fail = (!loader.predicates.is_empty()
-            (!loader.predicates.is_empty() &&
+            && loader.predicates.compilation_target != compilation_target)
-             loader.predicates.compilation_target != compilation_target) ||
+            || !key.is_consistent(&loader.predicates);
-            !key.is_consistent(&loader.predicates);
 
         let result = LiveTermStream::evacuate(loader);
         self.restore_load_state_payload(result, evacuable_h);
@@ -2263,5 +2256,6 @@ pub(super) fn load_module(
         code_dir,
         op_dir,
         meta_predicate_dir,
-    ).unwrap();
+    )
+    .unwrap();
 }

src/machine/machine_errors.rs

@@ -2,11 +2,11 @@ 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::loader::CompilationTarget;
 use crate::machine::machine_indices::*;
 use crate::machine::machine_state::*;
+use crate::machine::PredicateKey;
 use crate::rug::Integer;
 
 use std::rc::Rc;
@@ -321,14 +321,12 @@ impl MachineError {
             // SessionError::InvalidFileName(filename) => {
             //     Self::existence_error(h, ExistenceError::Module(filename))
             // }
-            SessionError::ModuleDoesNotContainExport(..) => {
+            SessionError::ModuleDoesNotContainExport(..) => Self::permission_error(
-                Self::permission_error(
+                h,
-                    h,
+                Permission::Access,
-                    Permission::Access,
+                "private_procedure",
-                    "private_procedure",
+                functor!("module_does_not_contain_claimed_export"),
-                    functor!("module_does_not_contain_claimed_export"),
+            ),
-                )
-            }
             SessionError::ModuleCannotImportSelf(module_name) => Self::permission_error(
                 h,
                 Permission::Modify,
@@ -417,7 +415,7 @@ impl MachineError {
 }
 
 #[derive(Debug)]
-pub enum CompilationError {
+pub(crate) enum CompilationError {
     Arithmetic(ArithmeticError),
     ParserError(ParserError),
     // BadPendingByte,
@@ -454,14 +452,14 @@ impl From<ParserError> for CompilationError {
 }
 
 impl CompilationError {
-    pub fn line_and_col_num(&self) -> Option<(usize, usize)> {
+    pub(crate) fn line_and_col_num(&self) -> Option<(usize, usize)> {
         match self {
             &CompilationError::ParserError(ref err) => err.line_and_col_num(),
             _ => None,
         }
     }
 
-    pub fn as_functor(&self, _h: usize) -> MachineStub {
+    pub(crate) fn as_functor(&self, _h: usize) -> MachineStub {
         match self {
             &CompilationError::Arithmetic(..) => functor!("arithmetic_error"),
             // &CompilationError::BadPendingByte =>
@@ -494,7 +492,7 @@ impl CompilationError {
 }
 
 #[derive(Debug, Clone, Copy)]
-pub enum Permission {
+pub(crate) enum Permission {
     Access,
     Create,
     InputStream,
@@ -506,7 +504,7 @@ pub enum Permission {
 
 impl Permission {
     #[inline]
-    pub fn as_str(self) -> &'static str {
+    pub(crate) fn as_str(self) -> &'static str {
         match self {
             Permission::Access => "access",
             Permission::Create => "create",
@@ -521,7 +519,7 @@ impl Permission {
 
 // from 7.12.2 b) of 13211-1:1995
 #[derive(Debug, Clone, Copy)]
-pub enum ValidType {
+pub(crate) enum ValidType {
     Atom,
     Atomic,
     //    Boolean,
@@ -543,7 +541,7 @@ pub enum ValidType {
 }
 
 impl ValidType {
-    pub fn as_str(self) -> &'static str {
+    pub(crate) fn as_str(self) -> &'static str {
         match self {
             ValidType::Atom => "atom",
             ValidType::Atomic => "atomic",
@@ -568,7 +566,7 @@ impl ValidType {
 }
 
 #[derive(Debug, Clone, Copy)]
-pub enum DomainErrorType {
+pub(crate) enum DomainErrorType {
     IOMode,
     NotLessThanZero,
     Order,
@@ -578,7 +576,7 @@ pub enum DomainErrorType {
 }
 
 impl DomainErrorType {
-    pub fn as_str(self) -> &'static str {
+    pub(crate) fn as_str(self) -> &'static str {
         match self {
             DomainErrorType::IOMode => "io_mode",
             DomainErrorType::NotLessThanZero => "not_less_than_zero",
@@ -592,7 +590,7 @@ impl DomainErrorType {
 
 // from 7.12.2 f) of 13211-1:1995
 #[derive(Debug, Clone, Copy)]
-pub enum RepFlag {
+pub(crate) enum RepFlag {
     Character,
     CharacterCode,
     InCharacterCode,
@@ -602,7 +600,7 @@ pub enum RepFlag {
 }
 
 impl RepFlag {
-    pub fn as_str(self) -> &'static str {
+    pub(crate) fn as_str(self) -> &'static str {
         match self {
             RepFlag::Character => "character",
             RepFlag::CharacterCode => "character_code",
@@ -616,7 +614,7 @@ impl RepFlag {
 
 // from 7.12.2 g) of 13211-1:1995
 #[derive(Debug, Clone, Copy)]
-pub enum EvalError {
+pub(crate) enum EvalError {
     FloatOverflow,
     Undefined,
     //    Underflow,
@@ -624,7 +622,7 @@ pub enum EvalError {
 }
 
 impl EvalError {
-    pub fn as_str(self) -> &'static str {
+    pub(crate) fn as_str(self) -> &'static str {
         match self {
             EvalError::FloatOverflow => "float_overflow",
             EvalError::Undefined => "undefined",
@@ -806,7 +804,7 @@ impl MachineState {
 }
 
 #[derive(Debug)]
-pub enum ExistenceError {
+pub(crate) enum ExistenceError {
     Module(ClauseName),
     ModuleSource(ModuleSource),
     Procedure(ClauseName, usize),
@@ -815,7 +813,7 @@ pub enum ExistenceError {
 }
 
 #[derive(Debug)]
-pub enum SessionError {
+pub(crate) enum SessionError {
     CompilationError(CompilationError),
     // CannotOverwriteBuiltIn(ClauseName),
     // CannotOverwriteImport(ClauseName),
@@ -830,7 +828,7 @@ pub enum SessionError {
 }
 
 #[derive(Debug)]
-pub enum EvalSession {
+pub(crate) enum EvalSession {
     // EntrySuccess,
     Error(SessionError),
 }

src/machine/machine_indices.rs

@@ -29,12 +29,12 @@ use std::ops::{Add, AddAssign, Deref, Sub, SubAssign};
 use std::rc::Rc;
 
 #[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct OrderedOpDirKey(pub ClauseName, pub Fixity);
+pub(crate) struct OrderedOpDirKey(pub(crate) ClauseName, pub(crate) Fixity);
 
-pub type OssifiedOpDir = BTreeMap<OrderedOpDirKey, (usize, Specifier)>;
+pub(crate) type OssifiedOpDir = BTreeMap<OrderedOpDirKey, (usize, Specifier)>;
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub enum DBRef {
+pub(crate) enum DBRef {
     NamedPred(ClauseName, usize, Option<SharedOpDesc>),
     Op(
         usize,
@@ -47,7 +47,7 @@ pub enum DBRef {
 
 // 7.2
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
-pub enum TermOrderCategory {
+pub(crate) enum TermOrderCategory {
     Variable,
     FloatingPoint,
     Integer,
@@ -56,7 +56,7 @@ pub enum TermOrderCategory {
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub enum Addr {
+pub(crate) enum Addr {
     AttrVar(usize),
     Char(char),
     Con(usize),
@@ -76,14 +76,14 @@ pub enum Addr {
 }
 
 #[derive(Debug, Clone, Copy, Hash, Eq, PartialEq, PartialOrd)]
-pub enum Ref {
+pub(crate) enum Ref {
     AttrVar(usize),
     HeapCell(usize),
     StackCell(usize, usize),
 }
 
 impl Ref {
-    pub fn as_addr(self) -> Addr {
+    pub(crate) fn as_addr(self) -> Addr {
         match self {
             Ref::AttrVar(h) => Addr::AttrVar(h),
             Ref::HeapCell(h) => Addr::HeapCell(h),
@@ -141,7 +141,7 @@ impl PartialOrd<Ref> for Addr {
 
 impl Addr {
     #[inline]
-    pub fn is_heap_bound(&self) -> bool {
+    pub(crate) fn is_heap_bound(&self) -> bool {
         match self {
             Addr::Char(_)
             | Addr::EmptyList
@@ -154,7 +154,7 @@ impl Addr {
     }
 
     #[inline]
-    pub fn is_ref(&self) -> bool {
+    pub(crate) fn is_ref(&self) -> bool {
         match self {
             Addr::HeapCell(_) | Addr::StackCell(_, _) | Addr::AttrVar(_) => true,
             _ => false,
@@ -162,7 +162,7 @@ impl Addr {
     }
 
     #[inline]
-    pub fn as_var(&self) -> Option<Ref> {
+    pub(crate) fn as_var(&self) -> Option<Ref> {
         match self {
             &Addr::AttrVar(h) => Some(Ref::AttrVar(h)),
             &Addr::HeapCell(h) => Some(Ref::HeapCell(h)),
@@ -202,7 +202,7 @@ impl Addr {
         }
     }
 
-    pub fn as_constant_index(&self, machine_st: &MachineState) -> Option<Constant> {
+    pub(crate) fn as_constant_index(&self, machine_st: &MachineState) -> Option<Constant> {
         match self {
             &Addr::Char(c) => Some(Constant::Char(c)),
             &Addr::Con(h) => match &machine_st.heap[h] {
@@ -222,7 +222,7 @@ impl Addr {
         }
     }
 
-    pub fn is_protected(&self, e: usize) -> bool {
+    pub(crate) fn is_protected(&self, e: usize) -> bool {
         match self {
             &Addr::StackCell(addr, _) if addr >= e => false,
             _ => true,
@@ -292,7 +292,7 @@ impl SubAssign<usize> for Addr {
 }
 
 #[derive(Debug, Clone, Copy)]
-pub enum TrailRef {
+pub(crate) enum TrailRef {
     Ref(Ref),
     AttrVarHeapLink(usize),
     AttrVarListLink(usize, usize),
@@ -307,7 +307,7 @@ impl From<Ref> for TrailRef {
 }
 
 #[derive(Debug)]
-pub enum HeapCellValue {
+pub(crate) enum HeapCellValue {
     Addr(Addr),
     Atom(ClauseName, Option<SharedOpDesc>),
     DBRef(DBRef),
@@ -322,13 +322,13 @@ pub enum HeapCellValue {
 
 impl HeapCellValue {
     #[inline]
-    pub fn as_addr(&self, focus: usize) -> Addr {
+    pub(crate) fn as_addr(&self, focus: usize) -> Addr {
         match self {
             HeapCellValue::Addr(ref a) => *a,
-            HeapCellValue::Atom(..) |
+            HeapCellValue::Atom(..)
-            HeapCellValue::DBRef(..) |
+            | HeapCellValue::DBRef(..)
-            HeapCellValue::Integer(..) |
+            | HeapCellValue::Integer(..)
-            HeapCellValue::Rational(..) => Addr::Con(focus),
+            | HeapCellValue::Rational(..) => Addr::Con(focus),
             HeapCellValue::LoadStatePayload(_) => Addr::LoadStatePayload(focus),
             HeapCellValue::NamedStr(_, _, _) => Addr::Str(focus),
             HeapCellValue::PartialString(..) => Addr::PStrLocation(focus, 0),
@@ -338,7 +338,7 @@ impl HeapCellValue {
     }
 
     #[inline]
-    pub fn context_free_clone(&self) -> HeapCellValue {
+    pub(crate) fn context_free_clone(&self) -> HeapCellValue {
         match self {
             &HeapCellValue::Addr(addr) => HeapCellValue::Addr(addr),
             &HeapCellValue::Atom(ref name, ref op) => HeapCellValue::Atom(name.clone(), op.clone()),
@@ -370,7 +370,7 @@ impl From<Addr> for HeapCellValue {
 }
 
 #[derive(Debug, Clone, Copy, Eq, Hash, Ord, PartialEq, PartialOrd)]
-pub enum IndexPtr {
+pub(crate) enum IndexPtr {
     DynamicUndefined, // a predicate, declared as dynamic, whose location in code is as yet undefined.
     DynamicIndex(usize),
     Index(usize),
@@ -378,7 +378,7 @@ pub enum IndexPtr {
 }
 
 #[derive(Debug, Clone, Ord, PartialOrd, Eq, PartialEq)]
-pub struct CodeIndex(pub Rc<Cell<IndexPtr>>);
+pub(crate) struct CodeIndex(pub(crate) Rc<Cell<IndexPtr>>);
 
 impl Deref for CodeIndex {
     type Target = Cell<IndexPtr>;
@@ -396,14 +396,14 @@ impl CodeIndex {
     }
 
     #[inline]
-    pub fn is_undefined(&self) -> bool {
+    pub(crate) fn is_undefined(&self) -> bool {
         match self.0.get() {
             IndexPtr::Undefined => true, // | &IndexPtr::DynamicUndefined => true,
             _ => false,
         }
     }
 
-    pub fn local(&self) -> Option<usize> {
+    pub(crate) fn local(&self) -> Option<usize> {
         match self.0.get() {
             IndexPtr::Index(i) => Some(i),
             IndexPtr::DynamicIndex(i) => Some(i),
@@ -419,7 +419,7 @@ impl Default for CodeIndex {
 }
 
 #[derive(Debug, Clone, Copy, PartialOrd, Ord, PartialEq, Eq)]
-pub enum REPLCodePtr {
+pub(crate) enum REPLCodePtr {
     AddDiscontiguousPredicate,
     AddDynamicPredicate,
     AddMultifilePredicate,
@@ -456,7 +456,7 @@ pub enum REPLCodePtr {
 }
 
 #[derive(Debug, Clone, PartialEq)]
-pub enum CodePtr {
+pub(crate) enum CodePtr {
     BuiltInClause(BuiltInClauseType, LocalCodePtr), // local is the successor call.
     CallN(usize, LocalCodePtr, bool),               // arity, local, last call.
     Local(LocalCodePtr),
@@ -466,7 +466,7 @@ pub enum CodePtr {
 }
 
 impl CodePtr {
-    pub fn local(&self) -> LocalCodePtr {
+    pub(crate) fn local(&self) -> LocalCodePtr {
         match self {
             &CodePtr::BuiltInClause(_, ref local)
             | &CodePtr::CallN(_, ref local, _)
@@ -477,7 +477,7 @@ impl CodePtr {
     }
 
     #[inline]
-    pub fn is_halt(&self) -> bool {
+    pub(crate) fn is_halt(&self) -> bool {
         if let CodePtr::Local(LocalCodePtr::Halt) = self {
             true
         } else {
@@ -487,7 +487,7 @@ impl CodePtr {
 }
 
 #[derive(Copy, Clone, Debug, PartialEq)]
-pub enum LocalCodePtr {
+pub(crate) enum LocalCodePtr {
     DirEntry(usize), // offset
     Halt,
     IndexingBuf(usize, usize, usize), // DirEntry offset, first internal offset, second internal offset
@@ -659,22 +659,23 @@ impl SubAssign<usize> for CodePtr {
     }
 }
 
-pub type HeapVarDict = IndexMap<Rc<Var>, Addr>;
+pub(crate) type HeapVarDict = IndexMap<Rc<Var>, Addr>;
-pub type AllocVarDict = IndexMap<Rc<Var>, VarData>;
+pub(crate) type AllocVarDict = IndexMap<Rc<Var>, VarData>;
 
-pub type GlobalVarDir = IndexMap<ClauseName, (Ball, Option<Addr>)>;
+pub(crate) type GlobalVarDir = IndexMap<ClauseName, (Ball, Option<Addr>)>;
 
 pub(crate) type StreamAliasDir = IndexMap<ClauseName, Stream>;
 pub(crate) type StreamDir = BTreeSet<Stream>;
 
-pub type MetaPredicateDir = IndexMap<PredicateKey, Vec<MetaSpec>>;
+pub(crate) type MetaPredicateDir = IndexMap<PredicateKey, Vec<MetaSpec>>;
 
-pub type ExtensiblePredicates = IndexMap<PredicateKey, PredicateSkeleton>;
+pub(crate) type ExtensiblePredicates = IndexMap<PredicateKey, PredicateSkeleton>;
 
-pub type LocalExtensiblePredicates = IndexMap<(CompilationTarget, PredicateKey), PredicateSkeleton>;
+pub(crate) type LocalExtensiblePredicates =
+    IndexMap<(CompilationTarget, PredicateKey), PredicateSkeleton>;
 
 #[derive(Debug)]
-pub struct IndexStore {
+pub(crate) struct IndexStore {
     pub(super) code_dir: CodeDir,
     pub(super) extensible_predicates: ExtensiblePredicates,
     pub(super) local_extensible_predicates: LocalExtensiblePredicates,
@@ -694,7 +695,7 @@ impl Default for IndexStore {
 }
 
 impl IndexStore {
-    pub fn get_predicate_skeleton_mut(
+    pub(crate) fn get_predicate_skeleton_mut(
         &mut self,
         compilation_target: &CompilationTarget,
         key: &PredicateKey,
@@ -714,29 +715,25 @@ impl IndexStore {
         }
     }
 
-    pub fn get_local_predicate_skeleton_mut(
+    pub(crate) fn get_local_predicate_skeleton_mut(
         &mut self,
         src_compilation_target: &CompilationTarget,
         local_compilation_target: CompilationTarget,
         key: PredicateKey,
     ) -> Option<&mut PredicateSkeleton> {
         match (key.0.as_str(), key.1) {
-            ("term_expansion", 2) => {
+            ("term_expansion", 2) => self
-                self.local_extensible_predicates.get_mut(
+                .local_extensible_predicates
-                    &(local_compilation_target, key),
+                .get_mut(&(local_compilation_target, key)),
-                )
-            }
             _ => match src_compilation_target {
-                CompilationTarget::User => {
+                CompilationTarget::User => self
-                    self.local_extensible_predicates.get_mut(
+                    .local_extensible_predicates
-                        &(local_compilation_target, key),
+                    .get_mut(&(local_compilation_target, key)),
-                    )
-                }
                 CompilationTarget::Module(ref module_name) => {
                     if let Some(module) = self.modules.get_mut(module_name) {
-                        module.local_extensible_predicates.get_mut(
+                        module
-                            &(local_compilation_target, key),
+                            .local_extensible_predicates
-                        )
+                            .get_mut(&(local_compilation_target, key))
                     } else {
                         None
                     }
@@ -745,29 +742,25 @@ impl IndexStore {
         }
     }
 
-    pub fn get_local_predicate_skeleton(
+    pub(crate) fn get_local_predicate_skeleton(
         &self,
         src_compilation_target: &CompilationTarget,
         local_compilation_target: CompilationTarget,
         key: PredicateKey,
     ) -> Option<&PredicateSkeleton> {
         match (key.0.as_str(), key.1) {
-            ("term_expansion", 2) => {
+            ("term_expansion", 2) => self
-                self.local_extensible_predicates.get(
+                .local_extensible_predicates
-                    &(local_compilation_target, key),
+                .get(&(local_compilation_target, key)),
-                )
-            }
             _ => match src_compilation_target {
-                CompilationTarget::User => {
+                CompilationTarget::User => self
-                    self.local_extensible_predicates.get(
+                    .local_extensible_predicates
-                        &(local_compilation_target, key),
+                    .get(&(local_compilation_target, key)),
-                    )
-                }
                 CompilationTarget::Module(ref module_name) => {
                     if let Some(module) = self.modules.get(module_name) {
-                        module.local_extensible_predicates.get(
+                        module
-                            &(local_compilation_target, key),
+                            .local_extensible_predicates
-                        )
+                            .get(&(local_compilation_target, key))
                     } else {
                         None
                     }
@@ -776,7 +769,7 @@ impl IndexStore {
         }
     }
 
-    pub fn get_predicate_skeleton(
+    pub(crate) fn get_predicate_skeleton(
         &self,
         compilation_target: &CompilationTarget,
         key: &PredicateKey,
@@ -796,19 +789,15 @@ impl IndexStore {
         }
     }
 
-    pub fn remove_predicate_skeleton(
+    pub(crate) fn remove_predicate_skeleton(
         &mut self,
         compilation_target: &CompilationTarget,
         key: &PredicateKey,
     ) -> Option<PredicateSkeleton> {
         match (key.0.as_str(), key.1) {
-            ("term_expansion", 2) => {
+            ("term_expansion", 2) => self.extensible_predicates.remove(key),
-                self.extensible_predicates.remove(key)
-            }
             _ => match compilation_target {
-                CompilationTarget::User => {
+                CompilationTarget::User => self.extensible_predicates.remove(key),
-                    self.extensible_predicates.remove(key)
-                }
                 CompilationTarget::Module(ref module_name) => {
                     if let Some(module) = self.modules.get_mut(module_name) {
                         module.extensible_predicates.remove(key)
@@ -820,7 +809,7 @@ impl IndexStore {
         }
     }
 
-    pub fn get_predicate_code_index(
+    pub(crate) fn get_predicate_code_index(
         &self,
         name: ClauseName,
         arity: usize,
@@ -848,7 +837,7 @@ impl IndexStore {
         }
     }
 
-    pub fn get_meta_predicate_spec(
+    pub(crate) fn get_meta_predicate_spec(
         &self,
         name: ClauseName,
         arity: usize,
@@ -866,7 +855,7 @@ impl IndexStore {
         }
     }
 
-    pub fn is_dynamic_predicate(&self, module_name: ClauseName, key: PredicateKey) -> bool {
+    pub(crate) fn is_dynamic_predicate(&self, module_name: ClauseName, key: PredicateKey) -> bool {
         match module_name.as_str() {
             "user" => self
                 .extensible_predicates
@@ -911,9 +900,9 @@ impl IndexStore {
     }
 }
 
-pub type CodeDir = BTreeMap<PredicateKey, CodeIndex>;
+pub(crate) type CodeDir = BTreeMap<PredicateKey, CodeIndex>;
 
-pub enum RefOrOwned<'a, T: 'a> {
+pub(crate) enum RefOrOwned<'a, T: 'a> {
     Borrowed(&'a T),
     Owned(T),
 }
@@ -928,14 +917,14 @@ impl<'a, T: 'a + fmt::Debug> fmt::Debug for RefOrOwned<'a, T> {
 }
 
 impl<'a, T> RefOrOwned<'a, T> {
-    pub fn as_ref(&'a self) -> &'a T {
+    pub(crate) fn as_ref(&'a self) -> &'a T {
         match self {
             &RefOrOwned::Borrowed(r) => r,
             &RefOrOwned::Owned(ref r) => r,
         }
     }
 
-    pub fn to_owned(self) -> T
+    pub(crate) fn to_owned(self) -> T
     where
         T: Clone,
     {

src/machine/machine_state.rs

@@ -30,7 +30,7 @@ use std::ops::{Index, IndexMut};
 use std::rc::Rc;
 
 #[derive(Debug)]
-pub struct Ball {
+pub(crate) struct Ball {
     pub(super) boundary: usize,
     pub(super) stub: Heap,
 }
@@ -225,7 +225,7 @@ impl IndexMut<RegType> for MachineState {
     }
 }
 
-pub type Registers = Vec<Addr>;
+pub(crate) type Registers = Vec<Addr>;
 
 #[derive(Debug, Clone, Copy)]
 pub(super) enum MachineMode {
@@ -276,7 +276,7 @@ pub enum FirstOrNext {
 }
 
 // #[derive(Debug)]
-pub struct MachineState {
+pub(crate) struct MachineState {
     pub(crate) atom_tbl: TabledData<Atom>,
     pub(super) s: HeapPtr,
     pub(super) p: CodePtr,
@@ -347,7 +347,7 @@ impl MachineState {
     pub(crate) fn read_term(&mut self, mut stream: Stream, indices: &mut IndexStore) -> CallResult {
         fn push_var_eq_functors<'a>(
             heap: &mut Heap,
-            iter: impl Iterator<Item=(&'a Rc<Var>, &'a Addr)>,
+            iter: impl Iterator<Item = (&'a Rc<Var>, &'a Addr)>,
             op_dir: &OpDir,
             atom_tbl: TabledData<Atom>,
         ) -> Vec<Addr> {
@@ -1303,7 +1303,8 @@ impl CallPolicy for CWILCallPolicy {
         offset: usize,
         global_variables: &mut GlobalVarDir,
     ) -> CallResult {
-        self.prev_policy.retry_me_else(machine_st, offset, global_variables)?;
+        self.prev_policy
+            .retry_me_else(machine_st, offset, global_variables)?;
         self.increment(machine_st)
     }
 
@@ -1313,7 +1314,8 @@ impl CallPolicy for CWILCallPolicy {
         offset: usize,
         global_variables: &mut GlobalVarDir,
     ) -> CallResult {
-        self.prev_policy.retry(machine_st, offset, global_variables)?;
+        self.prev_policy
+            .retry(machine_st, offset, global_variables)?;
         self.increment(machine_st)
     }
 
@@ -1332,7 +1334,8 @@ impl CallPolicy for CWILCallPolicy {
         offset: usize,
         global_variables: &mut GlobalVarDir,
     ) -> CallResult {
-        self.prev_policy.trust(machine_st, offset, global_variables)?;
+        self.prev_policy
+            .trust(machine_st, offset, global_variables)?;
         self.increment(machine_st)
     }
 

src/machine/machine_state_impl.rs

@@ -61,7 +61,7 @@ impl MachineState {
     }
 
     #[inline]
-    pub fn machine_flags(&self) -> MachineFlags {
+    pub(crate) fn machine_flags(&self) -> MachineFlags {
         self.flags
     }
 
@@ -590,8 +590,7 @@ impl MachineState {
         }
     }
 
-    pub(super)
+    pub(super) fn trail(&mut self, r: TrailRef) {
-    fn trail(&mut self, r: TrailRef) {
         match r {
             TrailRef::Ref(Ref::HeapCell(h)) => {
                 if h < self.hb {
@@ -3460,14 +3459,20 @@ impl MachineState {
             }
             &ChoiceInstruction::DefaultRetryMeElse(offset) => {
                 let mut call_policy = DefaultCallPolicy {};
-                try_or_fail!(self, call_policy.retry_me_else(self, offset, global_variables))
+                try_or_fail!(
+                    self,
+                    call_policy.retry_me_else(self, offset, global_variables)
+                )
             }
             &ChoiceInstruction::DefaultTrustMe(_) => {
                 let mut call_policy = DefaultCallPolicy {};
                 try_or_fail!(self, call_policy.trust_me(self, global_variables))
             }
             &ChoiceInstruction::RetryMeElse(offset) => {
-                try_or_fail!(self, call_policy.retry_me_else(self, offset, global_variables))
+                try_or_fail!(
+                    self,
+                    call_policy.retry_me_else(self, offset, global_variables)
+                )
             }
             &ChoiceInstruction::TrustMe(_) => {
                 try_or_fail!(self, call_policy.trust_me(self, global_variables))

src/machine/mod.rs

@@ -14,17 +14,17 @@ use crate::read::*;
 
 mod attributed_variables;
 pub(super) mod code_repo;
-pub mod code_walker;
+pub(crate) mod code_walker;
 #[macro_use]
 pub(crate) mod loader;
 mod compile;
 mod copier;
-pub mod heap;
+pub(crate) mod heap;
 mod load_state;
-pub mod machine_errors;
+pub(crate) mod machine_errors;
-pub mod machine_indices;
+pub(crate) mod machine_indices;
 pub(super) mod machine_state;
-pub mod partial_string;
+pub(crate) mod partial_string;
 mod preprocessor;
 mod raw_block;
 mod stack;
@@ -42,7 +42,7 @@ use crate::machine::compile::*;
 use crate::machine::machine_errors::*;
 use crate::machine::machine_indices::*;
 use crate::machine::machine_state::*;
-use crate::machine::streams::*;
+pub use crate::machine::streams::Stream;
 
 use indexmap::IndexMap;
 
@@ -54,13 +54,13 @@ use std::path::PathBuf;
 use std::sync::atomic::AtomicBool;
 
 #[derive(Debug)]
-pub struct MachinePolicies {
+pub(crate) struct MachinePolicies {
     call_policy: Box<dyn CallPolicy>,
     cut_policy: Box<dyn CutPolicy>,
 }
 
 lazy_static! {
-    pub static ref INTERRUPT: AtomicBool = AtomicBool::new(false);
+    pub(crate) static ref INTERRUPT: AtomicBool = AtomicBool::new(false);
 }
 
 impl MachinePolicies {
@@ -141,7 +141,7 @@ impl Machine {
         unreachable!();
     }
 
-    fn load_file(&mut self, path: String, stream: Stream) {
+    pub fn load_file(&mut self, path: String, stream: Stream) {
         self.machine_st[temp_v!(1)] =
             Addr::Stream(self.machine_st.heap.push(HeapCellValue::Stream(stream)));
 
@@ -224,7 +224,7 @@ impl Machine {
         self.run_module_predicate(clause_name!("$toplevel"), (clause_name!("$repl"), 1));
     }
 
-    fn configure_modules(&mut self) {
+    pub(crate) fn configure_modules(&mut self) {
         fn update_call_n_indices(loader: &Module, target_code_dir: &mut CodeDir) {
             for arity in 1..66 {
                 let key = (clause_name!("call"), arity);
@@ -358,7 +358,7 @@ impl Machine {
         wam
     }
 
-    pub fn configure_streams(&mut self) {
+    pub(crate) fn configure_streams(&mut self) {
         self.user_input.options_mut().alias = Some(clause_name!("user_input"));
 
         self.indices
@@ -493,7 +493,7 @@ impl Machine {
         self.machine_st.p = CodePtr::Local(p);
     }
 
-    pub(super) fn run_query(&mut self) {
+    pub(crate) fn run_query(&mut self) {
         while !self.machine_st.p.is_halt() {
             self.machine_st.query_stepper(
                 &mut self.indices,

src/machine/partial_string.rs

@@ -1,20 +1,20 @@
-use crate::machine::*;
 use crate::machine::machine_indices::*;
+use crate::machine::*;
 
 use core::marker::PhantomData;
 
 use std::alloc;
 use std::cmp::Ordering;
 use std::mem;
-use std::ptr;
 use std::ops::RangeFrom;
+use std::ptr;
 use std::slice;
 use std::str;
 
 use indexmap::IndexSet;
 
 #[derive(Debug)]
-pub struct PartialString {
+pub(crate) struct PartialString {
     buf: *const u8,
     len: usize,
     _marker: PhantomData<[u8]>,
@@ -54,7 +54,7 @@ fn scan_for_terminator<Iter: Iterator<Item = char>>(iter: Iter) -> usize {
 }
 
 #[derive(Debug)]
-pub struct PStrIter {
+pub(crate) struct PStrIter {
     buf: *const u8,
     len: usize,
 }
@@ -91,17 +91,14 @@ impl Iterator for PStrIter {
 
 impl PartialString {
     #[inline]
-    pub(super)
+    pub(super) fn new(src: &str) -> Option<(Self, &str)> {
-    fn new(src: &str) -> Option<(Self, &str)> {
         let pstr = PartialString {
             buf: ptr::null_mut(),
             len: 0,
             _marker: PhantomData,
         };
 
-        unsafe {
+        unsafe { pstr.append_chars(src) }
-            pstr.append_chars(src)
-        }
     }
 
     unsafe fn append_chars(mut self, src: &str) -> Option<(Self, &str)> {
@@ -115,29 +112,23 @@ impl PartialString {
         self.buf = alloc::alloc(layout) as *const _;
         self.len = terminator_idx + '\u{0}'.len_utf8();
 
-        ptr::copy(
+        ptr::copy(src.as_ptr(), self.buf as *mut _, terminator_idx);
-            src.as_ptr(),
-            self.buf as *mut _,
-            terminator_idx,
-        );
 
         self.write_terminator_at(terminator_idx);
 
         Some(if terminator_idx != src.as_bytes().len() {
-            (self, &src[terminator_idx ..])
+            (self, &src[terminator_idx..])
         } else {
             (self, "")
         })
     }
 
-    pub(super)
+    pub(super) fn clone_from_offset(&self, n: usize) -> Self {
-    fn clone_from_offset(&self, n: usize) -> Self {
+        let len = if self.len - '\u{0}'.len_utf8() > n {
-        let len =
+            self.len - n - '\u{0}'.len_utf8()
-            if self.len - '\u{0}'.len_utf8() > n {
+        } else {
-                self.len - n - '\u{0}'.len_utf8()
+            0
-            } else {
+        };
-                0
-            };
 
         let mut pstr = PartialString {
             buf: ptr::null_mut(),
@@ -168,18 +159,14 @@ impl PartialString {
     }
 
     #[inline]
-    pub(super)
+    pub(super) fn write_terminator_at(&mut self, index: usize) {
-    fn write_terminator_at(&mut self, index: usize) {
         unsafe {
-            ptr::write(
+            ptr::write((self.buf as usize + index) as *mut u8, 0u8);
-                (self.buf as usize + index) as *mut u8,
-                0u8,
-            );
         }
     }
 
     #[inline]
-    pub fn range_from(&self, index: RangeFrom<usize>) -> PStrIter {
+    pub(crate) fn range_from(&self, index: RangeFrom<usize>) -> PStrIter {
         if self.len >= '\u{0}'.len_utf8() {
             PStrIter::from(self.buf, self.len - '\u{0}'.len_utf8(), index.start)
         } else {
@@ -188,21 +175,18 @@ impl PartialString {
     }
 
     #[inline]
-    pub fn at_end(&self, end_n: usize) -> bool {
+    pub(crate) fn at_end(&self, end_n: usize) -> bool {
         end_n + 1 == self.len
     }
 
     #[inline]
-    pub fn as_str_from(&self, n: usize) -> &str {
+    pub(crate) fn as_str_from(&self, n: usize) -> &str {
         unsafe {
-            let slice = slice::from_raw_parts(
+            let slice = slice::from_raw_parts(self.buf, self.len - '\u{0}'.len_utf8());
-                self.buf,
-                self.len - '\u{0}'.len_utf8(),
-            );
 
             let s = str::from_utf8(slice).unwrap();
 
-            &s[n ..]
+            &s[n..]
         }
     }
 }
@@ -216,8 +200,7 @@ pub(crate) struct HeapPStrIter<'a> {
 
 impl<'a> HeapPStrIter<'a> {
     #[inline]
-    pub(super)
+    pub(super) fn new(machine_st: &'a MachineState, focus: Addr) -> Self {
-    fn new(machine_st: &'a MachineState, focus: Addr) -> Self {
         HeapPStrIter {
             focus,
             machine_st,
@@ -226,14 +209,12 @@ impl<'a> HeapPStrIter<'a> {
     }
 
     #[inline]
-    pub(crate)
+    pub(crate) fn focus(&self) -> Addr {
-    fn focus(&self) -> Addr {
         self.machine_st.store(self.machine_st.deref(self.focus))
     }
 
     #[inline]
-    pub(crate)
+    pub(crate) fn to_string(&mut self) -> String {
-    fn to_string(&mut self) -> String {
         let mut buf = String::new();
 
         while let Some(iteratee) = self.next() {
@@ -241,16 +222,14 @@ impl<'a> HeapPStrIter<'a> {
                 PStrIteratee::Char(c) => {
                     buf.push(c);
                 }
-                PStrIteratee::PStrSegment(h, n) => {
+                PStrIteratee::PStrSegment(h, n) => match &self.machine_st.heap[h] {
-                    match &self.machine_st.heap[h] {
+                    HeapCellValue::PartialString(ref pstr, _) => {
-                        HeapCellValue::PartialString(ref pstr, _) => {
+                        buf += pstr.as_str_from(n);
-                            buf += pstr.as_str_from(n);
-                        }
-                        _ => {
-                            unreachable!()
-                        }
                     }
-                }
+                    _ => {
+                        unreachable!()
+                    }
+                },
             }
         }
 
@@ -291,7 +270,9 @@ impl<'a> Iterator for HeapPStrIter<'a> {
                 }
             }
             Addr::Lis(l) => {
-                let addr = self.machine_st.store(self.machine_st.deref(Addr::HeapCell(l)));
+                let addr = self
+                    .machine_st
+                    .store(self.machine_st.deref(Addr::HeapCell(l)));
 
                 let opt_c = match addr {
                     Addr::Con(h) if self.machine_st.heap.atom_at(h) => {
@@ -305,12 +286,8 @@ impl<'a> Iterator for HeapPStrIter<'a> {
                             unreachable!()
                         }
                     }
-                    Addr::Char(c) => {
+                    Addr::Char(c) => Some(c),
-                        Some(c)
+                    _ => None,
-                    }
-                    _ => {
-                        None
-                    }
                 };
 
                 if let Some(c) = opt_c {
@@ -332,8 +309,7 @@ impl<'a> Iterator for HeapPStrIter<'a> {
 }
 
 #[inline]
-pub(super)
+pub(super) fn compare_pstr_prefixes<'a>(
-fn compare_pstr_prefixes<'a>(
     i1: &mut HeapPStrIter<'a>,
     i2: &mut HeapPStrIter<'a>,
 ) -> Option<Ordering> {
@@ -425,25 +401,16 @@ fn compare_pstr_prefixes<'a>(
         }
 
         return match (i1.focus(), i2.focus()) {
-            (Addr::EmptyList, Addr::EmptyList) => {
+            (Addr::EmptyList, Addr::EmptyList) => Some(Ordering::Equal),
-                Some(Ordering::Equal)
+            (Addr::EmptyList, _) => Some(Ordering::Less),
-            }
+            (_, Addr::EmptyList) => Some(Ordering::Greater),
-            (Addr::EmptyList, _) => {
+            _ => None,
-                Some(Ordering::Less)
-            }
-            (_, Addr::EmptyList) => {
-                Some(Ordering::Greater)
-            }
-            _ => {
-                None
-            }
         };
     }
 }
 
 #[inline]
-pub(super)
+pub(super) fn compare_pstr_to_string<'a>(
-fn compare_pstr_to_string<'a>(
     heap_pstr_iter: &mut HeapPStrIter<'a>,
     s: &String,
 ) -> Option<usize> {
@@ -452,7 +419,7 @@ fn compare_pstr_to_string<'a>(
     while let Some(iteratee) = heap_pstr_iter.next() {
         match iteratee {
             PStrIteratee::Char(c1) => {
-                if let Some(c2) = s[s_offset ..].chars().next() {
+                if let Some(c2) = s[s_offset..].chars().next() {
                     if c1 != c2 {
                         return None;
                     } else {
@@ -462,31 +429,28 @@ fn compare_pstr_to_string<'a>(
                     return Some(s_offset);
                 }
             }
-            PStrIteratee::PStrSegment(h, n) => {
+            PStrIteratee::PStrSegment(h, n) => match heap_pstr_iter.machine_st.heap[h] {
-                match heap_pstr_iter.machine_st.heap[h] {
+                HeapCellValue::PartialString(ref pstr, _) => {
-                    HeapCellValue::PartialString(ref pstr, _) => {
+                    let t = pstr.as_str_from(n);
-                        let t = pstr.as_str_from(n);
 
-                        if s[s_offset ..].starts_with(t) {
+                    if s[s_offset..].starts_with(t) {
-                            s_offset += t.len();
+                        s_offset += t.len();
-                        } else if t.starts_with(&s[s_offset ..]) {
+                    } else if t.starts_with(&s[s_offset..]) {
-                            heap_pstr_iter.focus =
+                        heap_pstr_iter.focus = Addr::PStrLocation(h, n + s[s_offset..].len());
-                                Addr::PStrLocation(h, n + s[s_offset ..].len());
 
-                            s_offset += s[s_offset ..].len();
+                        s_offset += s[s_offset..].len();
-                            return Some(s_offset);
+                        return Some(s_offset);
-                        } else {
+                    } else {
-                            return None;
+                        return None;
-                        }
-                    }
-                    _ => {
-                        unreachable!()
                     }
                 }
-            }
+                _ => {
+                    unreachable!()
+                }
+            },
         }
 
-        if s[s_offset ..].is_empty() {
+        if s[s_offset..].is_empty() {
             return Some(s_offset);
         }
     }

src/machine/preprocessor.rs

@@ -30,7 +30,7 @@ pub(crate) enum CutContext {
     HasCutVariable,
 }
 
-pub fn fold_by_str<I>(terms: I, mut term: Term, sym: ClauseName) -> Term
+pub(crate) fn fold_by_str<I>(terms: I, mut term: Term, sym: ClauseName) -> Term
 where
     I: DoubleEndedIterator<Item = Term>,
 {
@@ -46,7 +46,11 @@ where
     term
 }
 
-pub fn to_op_decl(prec: usize, spec: &str, name: ClauseName) -> Result<OpDecl, CompilationError> {
+pub(crate) fn to_op_decl(
+    prec: usize,
+    spec: &str,
+    name: ClauseName,
+) -> Result<OpDecl, CompilationError> {
     match spec {
         "xfx" => Ok(OpDecl::new(prec, XFX, name)),
         "xfy" => Ok(OpDecl::new(prec, XFY, name)),
@@ -825,11 +829,7 @@ impl Preprocessor {
         cut_context: CutContext,
     ) -> Result<Rule, CompilationError> {
         let post_head_terms: Vec<_> = terms.drain(1..).collect();
-        let mut query_terms = self.setup_query(
+        let mut query_terms = self.setup_query(load_state, post_head_terms, cut_context)?;
-            load_state,
-            post_head_terms,
-            cut_context,
-        )?;
 
         let clauses = query_terms.drain(1..).collect();
         let qt = query_terms.pop().unwrap();
@@ -894,11 +894,7 @@ impl Preprocessor {
         let mut results = VecDeque::new();
 
         for term in terms.into_iter() {
-            results.push_back(self.try_term_to_tl(
+            results.push_back(self.try_term_to_tl(load_state, term, cut_context)?);
-                load_state,
-                term,
-                cut_context,
-            )?);
         }
 
         Ok(results)

src/machine/stack.rs

@@ -23,9 +23,7 @@ impl RawBlockTraits for StackTraits {
 
     #[inline]
     fn base_offset(base: *const u8) -> *const u8 {
-        unsafe {
+        unsafe { base.offset(Self::align() as isize) }
-            base.offset(Self::align() as isize)
-        }
     }
 }
 
@@ -37,7 +35,7 @@ const fn prelude_size<Prelude>() -> usize {
 }
 
 #[derive(Debug)]
-pub struct Stack {
+pub(crate) struct Stack {
     buf: RawBlock<StackTraits>,
     _marker: PhantomData<Addr>,
 }
@@ -50,25 +48,25 @@ impl Drop for Stack {
 }
 
 #[derive(Debug, Clone, Copy)]
-pub struct FramePrelude {
+pub(crate) struct FramePrelude {
-    pub num_cells: usize,
+    pub(crate) num_cells: usize,
 }
 
 #[derive(Debug)]
-pub struct AndFramePrelude {
+pub(crate) struct AndFramePrelude {
-    pub univ_prelude: FramePrelude,
+    pub(crate) univ_prelude: FramePrelude,
-    pub e: usize,
+    pub(crate) e: usize,
-    pub cp: LocalCodePtr,
+    pub(crate) cp: LocalCodePtr,
-    pub interrupt_cp: LocalCodePtr,
+    pub(crate) interrupt_cp: LocalCodePtr,
 }
 
 #[derive(Debug)]
-pub struct AndFrame {
+pub(crate) struct AndFrame {
-    pub prelude: AndFramePrelude,
+    pub(crate) prelude: AndFramePrelude,
 }
 
 impl AndFrame {
-    pub fn size_of(num_cells: usize) -> usize {
+    pub(crate) fn size_of(num_cells: usize) -> usize {
         prelude_size::<AndFramePrelude>() + num_cells * mem::size_of::<Addr>()
     }
 }
@@ -104,23 +102,23 @@ impl IndexMut<usize> for AndFrame {
 }
 
 #[derive(Debug)]
-pub struct OrFramePrelude {
+pub(crate) struct OrFramePrelude {
-    pub univ_prelude: FramePrelude,
+    pub(crate) univ_prelude: FramePrelude,
-    pub e: usize,
+    pub(crate) e: usize,
-    pub cp: LocalCodePtr,
+    pub(crate) cp: LocalCodePtr,
-    pub b: usize,
+    pub(crate) b: usize,
-    pub bp: LocalCodePtr,
+    pub(crate) bp: LocalCodePtr,
-    pub tr: usize,
+    pub(crate) tr: usize,
-    pub pstr_tr: usize,
+    pub(crate) pstr_tr: usize,
-    pub h: usize,
+    pub(crate) h: usize,
-    pub b0: usize,
+    pub(crate) b0: usize,
-    pub attr_var_init_queue_b: usize,
+    pub(crate) attr_var_init_queue_b: usize,
-    pub attr_var_init_bindings_b: usize,
+    pub(crate) attr_var_init_bindings_b: usize,
 }
 
 #[derive(Debug)]
-pub struct OrFrame {
+pub(crate) struct OrFrame {
-    pub prelude: OrFramePrelude,
+    pub(crate) prelude: OrFramePrelude,
 }
 
 impl Index<usize> for OrFrame {
@@ -156,24 +154,27 @@ impl IndexMut<usize> for OrFrame {
 }
 
 impl OrFrame {
-    pub fn size_of(num_cells: usize) -> usize {
+    pub(crate) fn size_of(num_cells: usize) -> usize {
         prelude_size::<OrFramePrelude>() + num_cells * mem::size_of::<Addr>()
     }
 }
 
 impl Stack {
-    pub fn new() -> Self {
+    pub(crate) fn new() -> Self {
-        Stack { buf: RawBlock::new(), _marker: PhantomData }
+        Stack {
+            buf: RawBlock::new(),
+            _marker: PhantomData,
+        }
     }
 
-    pub fn allocate_and_frame(&mut self, num_cells: usize) -> usize {
+    pub(crate) fn allocate_and_frame(&mut self, num_cells: usize) -> usize {
         let frame_size = AndFrame::size_of(num_cells);
 
         unsafe {
             let new_top = self.buf.new_block(frame_size);
             let e = self.buf.top as usize - self.buf.base as usize;
 
-            for idx in 0 .. num_cells {
+            for idx in 0..num_cells {
                 let offset = prelude_size::<AndFramePrelude>() + idx * mem::size_of::<Addr>();
                 ptr::write(
                     (self.buf.top as usize + offset) as *mut Addr,
@@ -190,14 +191,14 @@ impl Stack {
         }
     }
 
-    pub fn allocate_or_frame(&mut self, num_cells: usize) -> usize {
+    pub(crate) fn allocate_or_frame(&mut self, num_cells: usize) -> usize {
         let frame_size = OrFrame::size_of(num_cells);
 
         unsafe {
             let new_top = self.buf.new_block(frame_size);
             let b = self.buf.top as usize - self.buf.base as usize;
 
-            for idx in 0 .. num_cells {
+            for idx in 0..num_cells {
                 let offset = prelude_size::<OrFramePrelude>() + idx * mem::size_of::<Addr>();
                 ptr::write(
                     (self.buf.top as usize + offset) as *mut Addr,
@@ -215,7 +216,7 @@ impl Stack {
     }
 
     #[inline]
-    pub fn index_and_frame(&self, e: usize) -> &AndFrame {
+    pub(crate) fn index_and_frame(&self, e: usize) -> &AndFrame {
         unsafe {
             let ptr = self.buf.base as usize + e;
             &*(ptr as *const AndFrame)
@@ -223,7 +224,7 @@ impl Stack {
     }
 
     #[inline]
-    pub fn index_and_frame_mut(&mut self, e: usize) -> &mut AndFrame {
+    pub(crate) fn index_and_frame_mut(&mut self, e: usize) -> &mut AndFrame {
         unsafe {
             let ptr = self.buf.base as usize + e;
             &mut *(ptr as *mut AndFrame)
@@ -231,7 +232,7 @@ impl Stack {
     }
 
     #[inline]
-    pub fn index_or_frame(&self, b: usize) -> &OrFrame {
+    pub(crate) fn index_or_frame(&self, b: usize) -> &OrFrame {
         unsafe {
             let ptr = self.buf.base as usize + b;
             &*(ptr as *const OrFrame)
@@ -239,7 +240,7 @@ impl Stack {
     }
 
     #[inline]
-    pub fn index_or_frame_mut(&mut self, b: usize) -> &mut OrFrame {
+    pub(crate) fn index_or_frame_mut(&mut self, b: usize) -> &mut OrFrame {
         unsafe {
             let ptr = self.buf.base as usize + b;
             &mut *(ptr as *mut OrFrame)
@@ -247,7 +248,7 @@ impl Stack {
     }
 
     #[inline]
-    pub fn truncate(&mut self, b: usize) {
+    pub(crate) fn truncate(&mut self, b: usize) {
         if b == 0 {
             self.inner_truncate(mem::align_of::<Addr>());
         } else {
@@ -264,7 +265,7 @@ impl Stack {
         }
     }
 
-    pub fn drop_in_place(&mut self) {
+    pub(crate) fn drop_in_place(&mut self) {
         self.truncate(mem::align_of::<Addr>());
 
         debug_assert!(if self.buf.top.is_null() {

src/machine/streams.rs

@@ -23,7 +23,7 @@ use std::rc::Rc;
 use native_tls::TlsStream;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub enum StreamType {
+pub(crate) enum StreamType {
     Binary,
     Text,
 }
@@ -55,14 +55,14 @@ impl StreamType {
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub enum EOFAction {
+pub(crate) enum EOFAction {
     EOFCode,
     Error,
     Reset,
 }
 
 #[derive(Debug, PartialEq)]
-pub enum AtEndOfStream {
+pub(crate) enum AtEndOfStream {
     Not,
     At,
     Past,
@@ -198,7 +198,7 @@ impl fmt::Debug for StreamInstance {
 }
 
 #[derive(Debug)]
-struct InnerStream {
+pub(crate) struct InnerStream {
     options: StreamOptions,
     stream_inst: StreamInstance,
     past_end_of_stream: bool,
@@ -211,14 +211,12 @@ struct WrappedStreamInstance(Rc<RefCell<InnerStream>>);
 impl WrappedStreamInstance {
     #[inline]
     fn new(stream_inst: StreamInstance, past_end_of_stream: bool) -> Self {
-        WrappedStreamInstance(Rc::new(RefCell::new(
+        WrappedStreamInstance(Rc::new(RefCell::new(InnerStream {
-            InnerStream {
+            options: StreamOptions::default(),
-                options: StreamOptions::default(),
+            stream_inst,
-                stream_inst,
+            past_end_of_stream,
-                past_end_of_stream,
+            lines_read: 0,
-                lines_read: 0,
+        })))
-            }
-        )))
     }
 }
 
@@ -287,11 +285,11 @@ impl fmt::Display for StreamError {
 impl Error for StreamError {}
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct StreamOptions {
+pub(crate) struct StreamOptions {
-    pub stream_type: StreamType,
+    pub(crate) stream_type: StreamType,
-    pub reposition: bool,
+    pub(crate) reposition: bool,
-    pub alias: Option<ClauseName>,
+    pub(crate) alias: Option<ClauseName>,
-    pub eof_action: EOFAction,
+    pub(crate) eof_action: EOFAction,
 }
 
 impl Default for StreamOptions {
@@ -366,6 +364,23 @@ impl Stream {
         ptr as *const u8
     }
 
+    pub fn bytes(&self) -> Option<std::cell::Ref<Vec<u8>>> {
+        // if Ref had an and_then function this could be simplified
+        let val = std::cell::Ref::map(self.stream_inst.0.borrow(), |inner_stream| {
+            &inner_stream.stream_inst
+        });
+        match std::ops::Deref::deref(&val) {
+            StreamInstance::Bytes(_) => Some(std::cell::Ref::map(
+                std::cell::Ref::clone(&val),
+                |instance| match instance {
+                    StreamInstance::Bytes(cursor) => cursor.get_ref(),
+                    _ => unreachable!(),
+                },
+            )),
+            _ => None,
+        }
+    }
+
     #[inline]
     pub(crate) fn lines_read(&mut self) -> usize {
         self.stream_inst.0.borrow_mut().lines_read
@@ -378,30 +393,29 @@ impl Stream {
 
     #[inline]
     pub(crate) fn options(&self) -> std::cell::Ref<'_, StreamOptions> {
-        std::cell::Ref::map(
+        std::cell::Ref::map(self.stream_inst.0.borrow(), |inner_stream| {
-            self.stream_inst.0.borrow(),
+            &inner_stream.options
-            |inner_stream| &inner_stream.options,
+        })
-        )
     }
 
     #[inline]
     pub(crate) fn options_mut(&mut self) -> std::cell::RefMut<'_, StreamOptions> {
-        std::cell::RefMut::map(
+        std::cell::RefMut::map(self.stream_inst.0.borrow_mut(), |inner_stream| {
-            self.stream_inst.0.borrow_mut(),
+            &mut inner_stream.options
-            |inner_stream| &mut inner_stream.options,
+        })
-        )
     }
 
     #[inline]
-    pub(crate) fn position(&mut self) -> Option<(u64, usize)> { // returns lines_read, position.
+    pub(crate) fn position(&mut self) -> Option<(u64, usize)> {
+        // returns lines_read, position.
         let result = match self.stream_inst.0.borrow_mut().stream_inst {
             StreamInstance::InputFile(_, ref mut file) => file.seek(SeekFrom::Current(0)).ok(),
-            StreamInstance::TcpStream(..) |
+            StreamInstance::TcpStream(..)
-            StreamInstance::TlsStream(..) |
+            | StreamInstance::TlsStream(..)
-            StreamInstance::ReadlineStream(..) |
+            | StreamInstance::ReadlineStream(..)
-            StreamInstance::StaticStr(..) |
+            | StreamInstance::StaticStr(..)
-            StreamInstance::PausedPrologStream(..) |
+            | StreamInstance::PausedPrologStream(..)
-            StreamInstance::Bytes(..) => Some(0),
+            | StreamInstance::Bytes(..) => Some(0),
             _ => None,
         };
 
@@ -411,9 +425,11 @@ impl Stream {
     #[inline]
     pub(crate) fn set_position(&mut self, position: u64) {
         match self.stream_inst.0.borrow_mut().deref_mut() {
-            InnerStream { past_end_of_stream,
+            InnerStream {
-                          stream_inst: StreamInstance::InputFile(_, ref mut file),
+                past_end_of_stream,
-                          .. } => {
+                stream_inst: StreamInstance::InputFile(_, ref mut file),
+                ..
+            } => {
                 file.seek(SeekFrom::Start(position)).unwrap();
 
                 if let Ok(metadata) = file.metadata() {
@@ -446,31 +462,31 @@ impl Stream {
         }
 
         match self.stream_inst.0.borrow_mut().deref_mut() {
-            InnerStream { past_end_of_stream,
+            InnerStream {
-                          stream_inst: StreamInstance::InputFile(_, ref mut file),
+                past_end_of_stream,
-                          .. } => {
+                stream_inst: StreamInstance::InputFile(_, ref mut file),
-                match file.metadata() {
+                ..
-                    Ok(metadata) => {
+            } => match file.metadata() {
-                        if let Ok(position) = file.seek(SeekFrom::Current(0)) {
+                Ok(metadata) => {
-                            return match position.cmp(&metadata.len()) {
+                    if let Ok(position) = file.seek(SeekFrom::Current(0)) {
-                                Ordering::Equal => AtEndOfStream::At,
+                        return match position.cmp(&metadata.len()) {
-                                Ordering::Less => AtEndOfStream::Not,
+                            Ordering::Equal => AtEndOfStream::At,
-                                Ordering::Greater => {
+                            Ordering::Less => AtEndOfStream::Not,
-                                    *past_end_of_stream = true;
+                            Ordering::Greater => {
-                                    AtEndOfStream::Past
+                                *past_end_of_stream = true;
-                                }
+                                AtEndOfStream::Past
-                            };
+                            }
-                        } else {
+                        };
-                            *past_end_of_stream = true;
+                    } else {
-                            AtEndOfStream::Past
-                        }
-                    }
-                    _ => {
                         *past_end_of_stream = true;
                         AtEndOfStream::Past
                     }
                 }
-            }
+                _ => {
+                    *past_end_of_stream = true;
+                    AtEndOfStream::Past
+                }
+            },
             _ => AtEndOfStream::Not,
         }
     }
@@ -488,11 +504,11 @@ impl Stream {
     #[inline]
     pub(crate) fn mode(&self) -> &'static str {
         match self.stream_inst.0.borrow().stream_inst {
-            StreamInstance::Bytes(_) |
+            StreamInstance::Bytes(_)
-            StreamInstance::PausedPrologStream(..) |
+            | StreamInstance::PausedPrologStream(..)
-            StreamInstance::ReadlineStream(_) |
+            | StreamInstance::ReadlineStream(_)
-            StreamInstance::StaticStr(_) |
+            | StreamInstance::StaticStr(_)
-            StreamInstance::InputFile(..) => "read",
+            | StreamInstance::InputFile(..) => "read",
             StreamInstance::TcpStream(..) | StreamInstance::TlsStream(..) => "read_append",
             StreamInstance::OutputFile(_, _, true) => "append",
             StreamInstance::Stdout | StreamInstance::OutputFile(_, _, false) => "write",
@@ -508,7 +524,7 @@ impl Stream {
     }
 
     #[inline]
-    pub(crate) fn stdout() -> Self {
+    pub fn stdout() -> Self {
         Stream::from_inst(StreamInstance::Stdout)
     }
 
@@ -568,13 +584,13 @@ impl Stream {
     #[inline]
     pub(crate) fn is_input_stream(&self) -> bool {
         match self.stream_inst.0.borrow().stream_inst {
-            StreamInstance::TcpStream(..) |
+            StreamInstance::TcpStream(..)
-            StreamInstance::TlsStream(..) |
+            | StreamInstance::TlsStream(..)
-            StreamInstance::Bytes(_) |
+            | StreamInstance::Bytes(_)
-            StreamInstance::PausedPrologStream(..) |
+            | StreamInstance::PausedPrologStream(..)
-            StreamInstance::ReadlineStream(_) |
+            | StreamInstance::ReadlineStream(_)
-            StreamInstance::StaticStr(_) |
+            | StreamInstance::StaticStr(_)
-            StreamInstance::InputFile(..) => true,
+            | StreamInstance::InputFile(..) => true,
             _ => false,
         }
     }
@@ -582,11 +598,11 @@ impl Stream {
     #[inline]
     pub(crate) fn is_output_stream(&self) -> bool {
         match self.stream_inst.0.borrow().stream_inst {
-            StreamInstance::Stdout |
+            StreamInstance::Stdout
-            StreamInstance::TcpStream(..) |
+            | StreamInstance::TcpStream(..)
-            StreamInstance::TlsStream(..) |
+            | StreamInstance::TlsStream(..)
-            StreamInstance::Bytes(_) |
+            | StreamInstance::Bytes(_)
-            StreamInstance::OutputFile(..) => true,
+            | StreamInstance::OutputFile(..) => true,
             _ => false,
         }
     }
@@ -1084,11 +1100,11 @@ impl Write for Stream {
             StreamInstance::TlsStream(_, ref mut tls_stream) => tls_stream.write(buf),
             StreamInstance::Bytes(ref mut cursor) => cursor.write(buf),
             StreamInstance::Stdout => stdout().write(buf),
-            StreamInstance::PausedPrologStream(..) |
+            StreamInstance::PausedPrologStream(..)
-            StreamInstance::StaticStr(_) |
+            | StreamInstance::StaticStr(_)
-            StreamInstance::ReadlineStream(_) |
+            | StreamInstance::ReadlineStream(_)
-            StreamInstance::InputFile(..) |
+            | StreamInstance::InputFile(..)
-            StreamInstance::Null => Err(std::io::Error::new(
+            | StreamInstance::Null => Err(std::io::Error::new(
                 ErrorKind::PermissionDenied,
                 StreamError::WriteToInputStream,
             )),
@@ -1102,11 +1118,11 @@ impl Write for Stream {
             StreamInstance::TlsStream(_, ref mut tls_stream) => tls_stream.flush(),
             StreamInstance::Bytes(ref mut cursor) => cursor.flush(),
             StreamInstance::Stdout => stdout().flush(),
-            StreamInstance::PausedPrologStream(..) |
+            StreamInstance::PausedPrologStream(..)
-            StreamInstance::StaticStr(_) |
+            | StreamInstance::StaticStr(_)
-            StreamInstance::ReadlineStream(_) |
+            | StreamInstance::ReadlineStream(_)
-            StreamInstance::InputFile(..) |
+            | StreamInstance::InputFile(..)
-            StreamInstance::Null => Err(std::io::Error::new(
+            | StreamInstance::Null => Err(std::io::Error::new(
                 ErrorKind::PermissionDenied,
                 StreamError::FlushToInputStream,
             )),

src/machine/system_calls.rs

@@ -71,7 +71,7 @@ use base64;
 use roxmltree;
 use select;
 
-pub fn get_key() -> KeyEvent {
+pub(crate) fn get_key() -> KeyEvent {
     let key;
     enable_raw_mode().expect("failed to enable raw mode");
     loop {

src/machine/term_stream.rs

@@ -78,7 +78,7 @@ impl<'a> TermStream for BootstrappingTermStream<'a> {
     }
 }
 
-pub struct LiveTermStream {
+pub(crate) struct LiveTermStream {
     pub(super) term_queue: VecDeque<Term>,
     pub(super) listing_src: ListingSource,
 }
@@ -93,7 +93,7 @@ impl LiveTermStream {
     }
 }
 
-pub struct LoadStatePayload {
+pub(crate) struct LoadStatePayload {
     pub(super) term_stream: LiveTermStream,
     pub(super) compilation_target: CompilationTarget,
     pub(super) retraction_info: RetractionInfo,

src/read.rs

@@ -12,7 +12,7 @@ use std::collections::VecDeque;
 
 type SubtermDeque = VecDeque<(usize, usize)>;
 
-pub type PrologStream = ParsingStream<Stream>;
+pub(crate) type PrologStream = ParsingStream<Stream>;
 
 pub mod readline {
     use crate::machine::streams::Stream;
@@ -24,7 +24,7 @@ pub mod readline {
 
     const HISTORY_FILE: &'static str = ".scryer_history";
 
-    pub fn set_prompt(value: bool) {
+    pub(crate) fn set_prompt(value: bool) {
         unsafe {
             PROMPT = value;
         }
@@ -49,10 +49,8 @@ pub mod readline {
 
     impl ReadlineStream {
         #[inline]
-        pub fn new(pending_input: String) -> Self {
+        pub(crate) fn new(pending_input: String) -> Self {
-            let config = Config::builder()
+            let config = Config::builder().check_cursor_position(true).build();
-                .check_cursor_position(true)
-                .build();
 
             let mut rl = Editor::<()>::with_config(config); //Editor::<()>::new();
             if let Some(mut path) = dirs_next::home_dir() {
@@ -72,7 +70,7 @@ pub mod readline {
         }
 
         #[inline]
-        pub fn input_stream(pending_input: String) -> Stream {
+        pub(crate) fn input_stream(pending_input: String) -> Stream {
             Stream::from(Self::new(pending_input))
         }
 
@@ -116,7 +114,7 @@ pub mod readline {
             }
         }
 
-        pub fn peek_byte(&mut self) -> std::io::Result<u8> {
+        pub(crate) fn peek_byte(&mut self) -> std::io::Result<u8> {
             set_prompt(false);
 
             loop {
@@ -137,7 +135,7 @@ pub mod readline {
             }
         }
 
-        pub fn peek_char(&mut self) -> std::io::Result<char> {
+        pub(crate) fn peek_char(&mut self) -> std::io::Result<char> {
             set_prompt(false);
 
             loop {
@@ -176,7 +174,7 @@ pub mod readline {
 }
 
 impl MachineState {
-    pub fn devour_whitespace(
+    pub(crate) fn devour_whitespace(
         &mut self,
         mut inner: Stream,
         atom_tbl: TabledData<Atom>,
@@ -196,7 +194,7 @@ impl MachineState {
         result
     }
 
-    pub fn read(
+    pub(crate) fn read(
         &mut self,
         mut inner: Stream,
         atom_tbl: TabledData<Atom>,
@@ -241,7 +239,7 @@ struct TermWriter<'a> {
 }
 
 #[derive(Debug)]
-pub struct TermWriteResult {
+pub(crate) struct TermWriteResult {
     pub(crate) heap_loc: usize,
     pub(crate) var_dict: HeapVarDict,
 }

src/targets.rs

@@ -5,7 +5,7 @@ use crate::forms::*;
 use crate::instructions::*;
 use crate::iterators::*;
 
-pub trait CompilationTarget<'a> {
+pub(crate) trait CompilationTarget<'a> {
     type Iterator: Iterator<Item = TermRef<'a>>;
 
     fn iter(_: &'a Term) -> Self::Iterator;

src/tests/hello_world.pl

@@ -0,0 +1,6 @@
+:- use_module(library(debug)).
+:- use_module(library(format)).
+
+hello_world :- write('Hello World!'), nl.
+
+:- initialization(hello_world).

tests/scryer.rs

@@ -0,0 +1,65 @@
+/// Loads the file and if some expected output is given checks that it matches
+fn test_file(file: &str, expected: Option<&[u8]>) {
+    use scryer_prolog::*;
+
+    let input = machine::Stream::from("");
+    let output = machine::Stream::from(String::new());
+
+    let mut wam = machine::Machine::new(input, output.clone());
+
+    wam.load_file(
+        file.into(),
+        machine::Stream::from(
+            std::fs::read_to_string(AsRef::<std::path::Path>::as_ref(file)).unwrap(),
+        ),
+    );
+
+    if let Some(expected) = expected {
+        let output = output.bytes().unwrap();
+        assert_eq!(output.as_slice(), expected);
+    }
+}
+
+#[test]
+fn builtins() {
+    test_file("src/tests/builtins.pl", Some(b""));
+}
+
+#[test]
+fn call_with_inference_limit() {
+    test_file("src/tests/call_with_inference_limit.pl", Some(b""));
+}
+
+#[test]
+fn facts() {
+    test_file("src/tests/facts.pl", Some(b""));
+}
+
+#[test]
+fn hello_world() {
+    test_file(
+        "src/tests/hello_world.pl",
+        Some("Hello World!\n".as_bytes()),
+    );
+}
+
+#[test]
+fn predicates() {
+    test_file("src/tests/predicates.pl", Some(b""));
+}
+
+#[test]
+fn rules() {
+    test_file("src/tests/rules.pl", Some(b""));
+}
+
+#[test]
+#[ignore] // ignored as this does not appear to terminate
+fn setup_call_cleanup() {
+    test_file("src/tests/setup_call_cleanup.pl", Some(b""));
+}
+
+#[test]
+fn clpz() {
+    test_file("src/tests/clpz/test_clpz.pl", Some(b""));
+}