Files
scryer-prolog/src/parser/ast.rs
2025-07-07 21:54:08 -07:00

1319 lines
33 KiB
Rust

#![allow(clippy::new_without_default)] // annotating structs annotated with #[bitfield] doesn't work
use crate::arena::*;
use crate::atom_table::*;
use crate::forms::PredicateKey;
use crate::machine::copier::*;
use crate::machine::heap::*;
use crate::machine::machine_indices::*;
use crate::machine::machine_state::*;
use crate::types::*;
use std::cell::{Ref, RefCell, RefMut};
use std::collections::VecDeque;
use std::fmt;
use std::hash::{Hash, Hasher};
use std::io::{Error as IOError, ErrorKind};
use std::ops::{Deref, Neg, RangeBounds};
use std::rc::Rc;
use std::sync::Arc;
use std::vec::Vec;
use crate::parser::dashu::{Integer, Rational};
use fxhash::FxBuildHasher;
use indexmap::IndexMap;
use scryer_modular_bitfield::error::OutOfBounds;
use scryer_modular_bitfield::prelude::*;
pub type Specifier = u32;
pub const MAX_ARITY: usize = 1023;
#[allow(clippy::upper_case_acronyms)]
#[derive(Debug, Clone, Copy, Eq, PartialEq)]
pub enum OpDeclSpec {
XFX = 0x0001,
XFY = 0x0002,
YFX = 0x0004,
XF = 0x0010,
YF = 0x0020,
FX = 0x0040,
FY = 0x0080,
}
pub use OpDeclSpec::*;
impl OpDeclSpec {
pub const fn value(self) -> u32 {
self as u32
}
pub fn get_spec(self) -> Atom {
match self {
XFX => atom!("xfx"),
XFY => atom!("xfy"),
YFX => atom!("yfx"),
FX => atom!("fx"),
FY => atom!("fy"),
XF => atom!("xf"),
YF => atom!("yf"),
}
}
pub const fn is_prefix(self) -> bool {
matches!(self, Self::FX | Self::FY)
}
pub const fn is_postfix(self) -> bool {
matches!(self, Self::XF | Self::YF)
}
pub const fn is_infix(self) -> bool {
matches!(self, Self::XFX | Self::XFY | Self::YFX)
}
pub const fn is_strict_left(self) -> bool {
matches!(self, Self::XFX | Self::XFY | Self::XF)
}
pub const fn is_strict_right(self) -> bool {
matches!(self, Self::XFX | Self::YFX | Self::FX)
}
#[inline(always)]
pub(crate) fn fixity(self) -> Fixity {
match self {
XFY | XFX | YFX => Fixity::In,
XF | YF => Fixity::Post,
FX | FY => Fixity::Pre,
}
}
}
impl From<OpDeclSpec> for u8 {
fn from(value: OpDeclSpec) -> Self {
value as u8
}
}
impl From<OpDeclSpec> for u32 {
fn from(value: OpDeclSpec) -> Self {
value as u32
}
}
impl TryFrom<u8> for OpDeclSpec {
type Error = ();
fn try_from(value: u8) -> Result<Self, Self::Error> {
Ok(match value {
0x0001 => XFX,
0x0002 => XFY,
0x0004 => YFX,
0x0010 => XF,
0x0020 => YF,
0x0040 => FX,
0x0080 => FY,
_ => return Err(()),
})
}
}
impl TryFrom<Atom> for OpDeclSpec {
type Error = ();
fn try_from(value: Atom) -> Result<Self, Self::Error> {
Ok(match value {
atom!("xfx") => Self::XFX,
atom!("xfy") => Self::XFY,
atom!("yfx") => Self::YFX,
atom!("fx") => Self::FX,
atom!("fy") => Self::FY,
atom!("xf") => Self::XF,
atom!("yf") => Self::YF,
_ => return Err(()),
})
}
}
pub const DELIMITER: u32 = 0x0100;
pub const TERM: u32 = 0x1000;
pub const LTERM: u32 = 0x3000;
pub const BTERM: u32 = 0x11000;
pub const NEGATIVE_SIGN: u32 = 0x0200;
macro_rules! fixnum {
($wrapper:tt, $n:expr, $arena:expr) => {
Fixnum::build_with_checked($n)
.map(<$wrapper>::Fixnum)
.unwrap_or_else(|_| <$wrapper>::Integer(arena_alloc!(Integer::from($n), $arena)))
};
}
macro_rules! is_term {
($x:expr) => {
($x as u32 & $crate::parser::ast::TERM) != 0 || is_negate!($x)
};
}
macro_rules! is_lterm {
($x:expr) => {
($x as u32 & $crate::parser::ast::LTERM) != 0 || is_negate!($x)
};
}
macro_rules! is_op {
($x:expr) => {
$x as u32
& ($crate::parser::ast::XF as u32
| $crate::parser::ast::YF as u32
| $crate::parser::ast::FX as u32
| $crate::parser::ast::FY as u32
| $crate::parser::ast::XFX as u32
| $crate::parser::ast::XFY as u32
| $crate::parser::ast::YFX as u32)
!= 0
};
}
macro_rules! is_negate {
($x:expr) => {
($x as u32 & $crate::parser::ast::NEGATIVE_SIGN) != 0
};
}
macro_rules! is_prefix {
($x:expr) => {
$x as u32 & ($crate::parser::ast::FX as u32 | $crate::parser::ast::FY as u32) != 0
};
}
macro_rules! is_infix {
($x:expr) => {
($x as u32
& ($crate::parser::ast::XFX as u32
| $crate::parser::ast::XFY as u32
| $crate::parser::ast::YFX as u32))
!= 0
};
}
macro_rules! is_xfx {
($x:expr) => {
($x as u32 & $crate::parser::ast::XFX as u32) != 0
};
}
macro_rules! is_xfy {
($x:expr) => {
($x as u32 & $crate::parser::ast::XFY as u32) != 0
};
}
macro_rules! is_yfx {
($x:expr) => {
($x as u32 & $crate::parser::ast::YFX as u32) != 0
};
}
macro_rules! is_yf {
($x:expr) => {
($x as u32 & $crate::parser::ast::YF as u32) != 0
};
}
macro_rules! is_xf {
($x:expr) => {
($x as u32 & $crate::parser::ast::XF as u32) != 0
};
}
macro_rules! is_fx {
($x:expr) => {
($x as u32 & $crate::parser::ast::FX as u32) != 0
};
}
macro_rules! is_fy {
($x:expr) => {
($x as u32 & $crate::parser::ast::FY as u32) != 0
};
}
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub enum RegType {
Perm(usize),
Temp(usize),
}
impl Default for RegType {
fn default() -> Self {
RegType::Temp(0)
}
}
impl RegType {
pub fn reg_num(self) -> usize {
match self {
RegType::Perm(reg_num) | RegType::Temp(reg_num) => reg_num,
}
}
pub fn is_perm(self) -> bool {
matches!(self, RegType::Perm(_))
}
}
impl fmt::Display for RegType {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
RegType::Perm(val) => write!(f, "Y{}", val),
RegType::Temp(val) => write!(f, "X{}", val),
}
}
}
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
pub enum VarReg {
ArgAndNorm(RegType, usize),
Norm(RegType),
}
impl VarReg {
pub fn norm(self) -> RegType {
match self {
VarReg::ArgAndNorm(reg, _) | VarReg::Norm(reg) => reg,
}
}
}
impl fmt::Display for VarReg {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
VarReg::Norm(RegType::Perm(reg)) => write!(f, "Y{}", reg),
VarReg::Norm(RegType::Temp(reg)) => write!(f, "X{}", reg),
VarReg::ArgAndNorm(RegType::Perm(reg), arg) => write!(f, "Y{} A{}", reg, arg),
VarReg::ArgAndNorm(RegType::Temp(reg), arg) => write!(f, "X{} A{}", reg, arg),
}
}
}
impl Default for VarReg {
fn default() -> Self {
VarReg::Norm(RegType::default())
}
}
macro_rules! temp_v {
($x:expr) => {
$crate::parser::ast::RegType::Temp($x)
};
}
#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub enum GenContext {
Head,
Mid(usize),
Last(usize), // Mid & Last: chunk_num
}
impl GenContext {
#[inline]
pub fn chunk_num(self) -> usize {
match self {
GenContext::Head => 0,
GenContext::Mid(cn) | GenContext::Last(cn) => cn,
}
}
#[inline]
pub fn is_last(self) -> bool {
matches!(self, GenContext::Last(_))
}
}
#[bitfield]
#[derive(Copy, Clone, Debug, PartialEq, Eq, Ord, PartialOrd, Hash)]
pub struct OpDesc {
prec: B11,
spec: B8,
#[allow(unused)]
padding: B13,
}
impl OpDesc {
#[inline]
pub fn build_with(prec: u16, spec: OpDeclSpec) -> Self {
OpDesc::new().with_spec(spec as u8).with_prec(prec)
}
#[inline]
pub fn get(self) -> (u16, OpDeclSpec) {
(self.prec(), self.get_spec())
}
pub fn set(&mut self, prec: u16, spec: OpDeclSpec) {
self.set_prec(prec);
self.set_spec(spec as u8);
}
#[inline]
pub fn get_prec(self) -> u16 {
self.prec()
}
#[inline]
pub fn get_spec(self) -> OpDeclSpec {
OpDeclSpec::try_from(self.spec()).expect("OpDecl always contains a valud OpDeclSpec")
}
#[inline]
pub fn arity(self) -> usize {
if !self.get_spec().is_infix() {
1
} else {
2
}
}
}
// name and fixity -> operator type and precedence.
pub type OpDir = IndexMap<(Atom, Fixity), OpDesc, FxBuildHasher>;
#[derive(Debug, Default, Clone, Copy)]
pub struct MachineFlags {
pub double_quotes: DoubleQuotes,
pub unknown: Unknown,
}
#[derive(Debug, Default, Clone, Copy, PartialEq)]
pub enum DoubleQuotes {
Atom,
#[default]
Chars,
Codes,
}
impl DoubleQuotes {
pub fn is_chars(self) -> bool {
matches!(self, DoubleQuotes::Chars)
}
pub fn is_codes(self) -> bool {
matches!(self, DoubleQuotes::Codes)
}
}
#[derive(Debug, Clone, Copy, Default)]
pub enum Unknown {
#[default]
Error,
Fail,
Warn,
}
pub fn default_op_dir() -> OpDir {
let mut op_dir = OpDir::with_hasher(FxBuildHasher::default());
op_dir.insert((atom!(":-"), Fixity::In), OpDesc::build_with(1200, XFX));
op_dir.insert((atom!(":-"), Fixity::Pre), OpDesc::build_with(1200, FX));
op_dir.insert((atom!("?-"), Fixity::Pre), OpDesc::build_with(1200, FX));
op_dir.insert((atom!(","), Fixity::In), OpDesc::build_with(1000, XFY));
op_dir
}
#[derive(Debug, Clone)]
pub enum ArithmeticError {
NonEvaluableFunctor(Literal, usize),
UninstantiatedVar,
}
#[derive(Debug, Copy, Clone, Default)]
pub struct ParserErrorSrc {
pub col_num: usize,
pub line_num: usize,
}
#[derive(Debug)]
pub enum ParserError {
BackQuotedString(ParserErrorSrc),
IO(IOError, ParserErrorSrc),
IncompleteReduction(ParserErrorSrc),
InfiniteFloat(ParserErrorSrc),
InvalidSingleQuotedCharacter(char, ParserErrorSrc),
LexicalError(lexical::Error, ParserErrorSrc),
MissingQuote(ParserErrorSrc),
NonPrologChar(ParserErrorSrc),
ParseBigInt(ParserErrorSrc),
UnexpectedChar(char, ParserErrorSrc),
// UnexpectedEOF,
Utf8Error(ParserErrorSrc),
}
impl ParserError {
pub fn err_src(&self) -> ParserErrorSrc {
match self {
&ParserError::BackQuotedString(err_src)
| &ParserError::IO(_, err_src)
| &ParserError::IncompleteReduction(err_src)
| &ParserError::InfiniteFloat(err_src)
| &ParserError::InvalidSingleQuotedCharacter(_, err_src)
| &ParserError::LexicalError(_, err_src)
| &ParserError::MissingQuote(err_src)
| &ParserError::NonPrologChar(err_src)
| &ParserError::ParseBigInt(err_src)
| &ParserError::UnexpectedChar(_, err_src)
| &ParserError::Utf8Error(err_src) => err_src,
}
}
pub fn as_atom(&self) -> Atom {
match self {
ParserError::BackQuotedString(..) => atom!("back_quoted_string"),
ParserError::IncompleteReduction(..) => atom!("incomplete_reduction"),
ParserError::InvalidSingleQuotedCharacter(..) => {
atom!("invalid_single_quoted_character")
}
ParserError::InfiniteFloat(..) => {
atom!("infinite_float")
}
ParserError::IO(e, _) if e.kind() == ErrorKind::UnexpectedEof => {
atom!("unexpected_end_of_file")
}
ParserError::IO(e, _) if e.kind() == ErrorKind::InvalidData => {
atom!("invalid_data")
}
ParserError::IO(..) => atom!("input_output_error"),
ParserError::LexicalError(..) => atom!("lexical_error"),
ParserError::MissingQuote(..) => atom!("missing_quote"),
ParserError::NonPrologChar(..) => atom!("non_prolog_character"),
ParserError::ParseBigInt(..) => atom!("cannot_parse_big_int"),
ParserError::UnexpectedChar(..) => atom!("unexpected_char"),
ParserError::Utf8Error(..) => atom!("utf8_conversion_error"),
}
}
#[inline]
pub fn unexpected_eof(err_src: ParserErrorSrc) -> Self {
ParserError::IO(std::io::Error::from(ErrorKind::UnexpectedEof), err_src)
}
#[inline]
pub fn is_unexpected_eof(&self) -> bool {
if let ParserError::IO(e, _) = self {
e.kind() == ErrorKind::UnexpectedEof
} else {
false
}
}
}
/*
impl From<lexical::Error> for ParserError {
fn from((e, err_src): (lexical::Error, ParserErrorSrc)) -> ParserError {
ParserError::LexicalError(e, err_src)
}
}
impl From<IOError> for ParserError {
fn from(e: IOError) -> ParserError {
ParserError::IO(e)
}
}
impl From<&IOError> for ParserError {
fn from(error: &IOError) -> ParserError {
if error.get_ref().filter(|e| e.is::<BadUtf8Error>()).is_some() {
ParserError::Utf8Error(0, 0)
} else {
ParserError::IO(error.kind().into())
}
}
}
*/
#[derive(Debug, Clone, Copy)]
pub struct CompositeOpDir<'a, 'b> {
pub primary_op_dir: Option<&'b OpDir>,
pub secondary_op_dir: &'a OpDir,
}
impl<'a, 'b> CompositeOpDir<'a, 'b> {
#[inline]
pub fn new(secondary_op_dir: &'a OpDir, primary_op_dir: Option<&'b OpDir>) -> Self {
CompositeOpDir {
primary_op_dir,
secondary_op_dir,
}
}
#[inline]
pub(crate) fn get(&self, name: Atom, fixity: Fixity) -> Option<OpDesc> {
let entry = if let Some(primary_op_dir) = &self.primary_op_dir {
primary_op_dir.get(&(name, fixity))
} else {
None
};
entry
.or_else(move || self.secondary_op_dir.get(&(name, fixity)))
.cloned()
}
}
#[derive(Debug, Clone, Copy, Eq, Hash, PartialEq, PartialOrd, Ord)]
pub enum Fixity {
In,
Post,
Pre,
}
#[bitfield]
#[repr(u64)]
#[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)]
pub struct Fixnum {
num: B56,
#[allow(unused)]
f: bool,
#[allow(unused)]
m: bool,
#[allow(unused)]
tag: B6,
}
impl Fixnum {
#[inline]
pub fn build_with(num: i64) -> Self {
Fixnum::new()
.with_num(u64::from_ne_bytes(num.to_ne_bytes()) & ((1 << 56) - 1))
.with_tag(HeapCellValueTag::Fixnum as u8)
.with_m(false)
.with_f(false)
}
#[inline]
pub fn as_cutpoint(num: i64) -> Self {
Fixnum::new()
.with_num(u64::from_ne_bytes(num.to_ne_bytes()) & ((1 << 56) - 1))
.with_tag(HeapCellValueTag::CutPoint as u8)
.with_m(false)
.with_f(false)
}
#[inline]
pub fn get_tag(&self) -> HeapCellValueTag {
use scryer_modular_bitfield::Specifier;
HeapCellValueTag::from_bytes(self.tag()).unwrap()
}
#[inline]
pub fn build_with_checked(num: i64) -> Result<Self, OutOfBounds> {
const UPPER_BOUND: i64 = (1 << 55) - 1;
const LOWER_BOUND: i64 = -(1 << 55);
if (LOWER_BOUND..=UPPER_BOUND).contains(&num) {
Ok(Fixnum::new()
.with_m(false)
.with_f(false)
.with_tag(HeapCellValueTag::Fixnum as u8)
.with_num(u64::from_ne_bytes(num.to_ne_bytes()) & ((1 << 56) - 1)))
} else {
Err(OutOfBounds {})
}
}
#[inline]
pub fn get_num(self) -> i64 {
let n = self.num() as i64;
let (n, overflowed) = (n << 8).overflowing_shr(8);
debug_assert!(!overflowed);
n
}
}
impl Neg for Fixnum {
type Output = Self;
#[inline]
fn neg(self) -> Self::Output {
Fixnum::build_with(-self.get_num())
}
}
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
pub enum Literal {
Atom(Atom),
Char(char),
CodeIndex(CodeIndex),
Fixnum(Fixnum),
Integer(TypedArenaPtr<Integer>),
Rational(TypedArenaPtr<Rational>),
Float(F64Offset),
String(Atom),
}
impl From<F64Ptr> for Literal {
#[inline(always)]
fn from(ptr: F64Ptr) -> Literal {
Literal::Float(ptr.as_offset())
}
}
impl fmt::Display for Literal {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
Literal::Atom(ref atom) => {
write!(f, "{}", atom.flat_index())
}
Literal::Char(c) => write!(f, "'{}'", *c as u32),
Literal::CodeIndex(i) => write!(f, "{:x}", i.as_ptr() as u64),
Literal::Fixnum(n) => write!(f, "{}", n.get_num()),
Literal::Integer(ref n) => write!(f, "{}", n),
Literal::Rational(ref n) => write!(f, "{}", n),
Literal::Float(ref n) => write!(f, "{}", *n),
Literal::String(ref s) => write!(f, "\"{}\"", s.as_str()),
}
}
}
impl Literal {
pub fn as_atom(&self, atom_tbl: &Arc<AtomTable>) -> Option<Atom> {
match self {
Literal::Atom(atom) => Some(atom.defrock_brackets(atom_tbl)),
_ => None,
}
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct VarPtr(Rc<RefCell<Var>>);
impl Hash for VarPtr {
#[inline(always)]
fn hash<H: Hasher>(&self, hasher: &mut H) {
self.borrow().hash(hasher)
}
}
impl Deref for VarPtr {
type Target = RefCell<Var>;
#[inline(always)]
fn deref(&self) -> &Self::Target {
self.0.deref()
}
}
impl VarPtr {
#[inline]
pub(crate) fn is_anon(&self) -> bool {
match *self.borrow() {
Var::Anon | Var::Generated { is_anon: true, .. } => true,
_ => false,
}
}
#[inline(always)]
pub(crate) fn borrow(&self) -> Ref<'_, Var> {
self.0.borrow()
}
#[inline(always)]
pub(crate) fn borrow_mut(&self) -> RefMut<'_, Var> {
self.0.borrow_mut()
}
pub(crate) fn to_var_num(&self) -> Option<usize> {
match *self.borrow() {
Var::Generated { var_num, .. } => Some(var_num),
_ => None,
}
}
pub(crate) fn set(&self, var: Var) {
let mut var_ref = self.borrow_mut();
*var_ref = var;
}
}
impl From<Var> for VarPtr {
#[inline(always)]
fn from(value: Var) -> VarPtr {
VarPtr(Rc::new(RefCell::new(value)))
}
}
impl From<String> for VarPtr {
#[inline(always)]
fn from(value: String) -> VarPtr {
VarPtr::from(Var::from(value))
}
}
impl From<&str> for VarPtr {
#[inline(always)]
fn from(value: &str) -> VarPtr {
VarPtr::from(value.to_owned())
}
}
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum Var {
Anon,
Generated { is_anon: bool, var_num: usize },
InSitu(usize),
Named(String),
}
impl From<String> for Var {
#[inline(always)]
fn from(value: String) -> Var {
Var::Named(value)
}
}
impl From<&str> for Var {
#[inline(always)]
fn from(value: &str) -> Var {
Var::Named(value.to_owned())
}
}
impl Var {
#[allow(clippy::inherent_to_string)]
#[inline(always)]
pub fn to_string(&self) -> String {
match self {
Var::Anon => "_".to_owned(),
Var::InSitu(var_num) | Var::Generated { var_num, .. } => format!("_{}", var_num),
Var::Named(value) => value.to_owned(),
}
}
}
pub(crate) fn subterm_index(heap: &[HeapCellValue], subterm_loc: usize) -> (usize, HeapCellValue) {
let subterm = heap[subterm_loc];
if subterm.is_ref() {
let subterm = heap_bound_deref(heap, subterm);
let subterm_loc = subterm.get_value() as usize;
let subterm = heap_bound_store(heap, subterm);
let subterm_loc = if subterm.is_ref() {
subterm.get_value() as usize
} else {
subterm_loc
};
(subterm_loc, subterm)
} else {
(subterm_loc, subterm)
}
}
/*
#[derive(Debug, Clone)]
pub enum Term {
AnonVar,
Clause(Cell<RegType>, Atom, Vec<Term>),
Cons(Cell<RegType>, Box<Term>, Box<Term>),
Literal(Cell<RegType>, Literal),
// PartialString wraps a String in anticipation of it absorbing
// other PartialString variants in as_partial_string.
PartialString(Cell<RegType>, String, Box<Term>),
CompleteString(Cell<RegType>, Atom),
Var(Cell<VarReg>, VarPtr),
}
impl Term {
pub fn first_arg(&self) -> Option<&Term> {
match self {
Term::Clause(_, _, ref terms) => terms.first(),
_ => None,
}
}
pub fn name(&self) -> Option<Atom> {
match self {
&Term::Literal(_, Literal::Atom(ref atom)) | &Term::Clause(_, ref atom, ..) => {
Some(*atom)
}
_ => None,
}
}
pub fn arity(&self) -> usize {
match self {
Term::Clause(_, _, ref child_terms, ..) => child_terms.len(),
_ => 0,
}
}
}
pub(crate) fn unfold_by_str_once(term: &mut Term, s: Atom) -> Option<(Term, Term)> {
if let Term::Clause(_, ref name, ref mut subterms) = term {
if let Some(Term::Literal(_, Literal::CodeIndex(_))) = subterms.last() {
subterms.pop();
}
if name == &s && subterms.len() == 2 {
let snd = subterms.pop().unwrap();
let fst = subterms.pop().unwrap();
return Some((fst, snd));
}
}
None
}
pub fn unfold_by_str(mut term: Term, s: Atom) -> Vec<Term> {
let mut terms = vec![];
while let Some((fst, snd)) = unfold_by_str_once(&mut term, s) {
terms.push(fst);
term = snd;
}
terms.push(term);
terms
}
*/
pub(crate) fn fetch_index_ptr(
heap: &[HeapCellValue],
arity: usize,
term_loc: usize,
) -> Option<CodeIndex> {
if term_loc + arity + 1 >= heap.len() {
return None;
}
read_heap_cell!(heap[term_loc + arity + 1],
(HeapCellValueTag::Cons, c) => {
match_untyped_arena_ptr!(c,
(ArenaHeaderTag::IndexPtr, ptr) => {
return Some(CodeIndex::from(ptr));
}
_ => {}
);
}
_ => {}
);
None
}
pub(crate) fn blunt_index_ptr(
heap: &mut [HeapCellValue],
key: PredicateKey,
term_loc: usize,
) -> bool {
if fetch_index_ptr(heap, key.1, term_loc).is_some() {
heap[term_loc] = atom_as_cell!(key.0, key.1);
true
} else {
false
}
}
pub(crate) fn unfold_by_str_once(
heap: &mut [HeapCellValue],
start_term: HeapCellValue,
atom: Atom,
) -> Option<usize> {
let start_term = heap_bound_store(
heap,
heap_bound_deref(heap, start_term),
);
if let HeapCellValueTag::Str = start_term.get_tag() {
let s = start_term.get_value() as usize;
let (s_atom, s_arity) = cell_as_atom_cell!(heap[s]).get_name_and_arity();
blunt_index_ptr(heap, (s_atom, s_arity), s);
if (s_atom, s_arity) == (atom, 2) {
return Some(s+1);
}
}
None
}
pub fn unfold_by_str(
heap: &mut [HeapCellValue],
mut start_term: HeapCellValue,
atom: Atom,
) -> Vec<HeapCellValue> {
let mut terms = vec![];
start_term = heap_bound_store(heap, heap_bound_deref(heap, start_term));
while let Some(fst_loc) = unfold_by_str_once(heap, start_term, atom) {
let (_, snd) = subterm_index(heap, fst_loc + 1);
let (_, fst) = subterm_index(heap, fst_loc);
terms.push(fst);
start_term = snd;
}
terms
}
/*
pub fn unfold_by_str_locs(
heap: &mut [HeapCellValue],
mut term_loc: usize,
atom: Atom,
) -> Vec<(HeapCellValue, usize)> {
let mut terms = vec![];
let mut current_term = heap_bound_store(
heap,
heap_bound_deref(heap, heap[term_loc]),
);
while let Some(fst_loc) = unfold_by_str_once(heap, current_term, atom) {
(term_loc, current_term) = subterm_index(heap, fst_loc + 1);
let (fst_loc, fst) = subterm_index(heap, fst_loc);
terms.push((fst, fst_loc));
}
terms.push((current_term, term_loc));
terms
}
*/
pub fn unfold_by_str_locs(
heap: &mut [HeapCellValue],
mut term_loc: usize,
atom: Atom,
) -> Vec<(HeapCellValue, usize)> {
let mut terms = vec![];
let mut current_term = heap[term_loc];
while let Some(fst_loc) = unfold_by_str_once(heap, current_term, atom) {
term_loc = fst_loc+1;
current_term = heap[term_loc];
let fst = heap[fst_loc];
terms.push((fst, fst_loc));
}
terms.push((current_term, term_loc));
terms
}
pub fn term_name(heap: &[HeapCellValue], mut term_loc: usize) -> Option<Atom> {
loop {
read_heap_cell!(heap[term_loc],
(HeapCellValueTag::Atom, (name, _arity)) => {
return Some(name);
}
(HeapCellValueTag::Str, s) => {
term_loc = s;
}
(HeapCellValueTag::AttrVar | HeapCellValueTag::Var, h) => {
if h != term_loc {
term_loc = h;
} else {
return None;
}
}
_ => {
return None;
}
);
}
}
pub fn term_arity(heap: &[HeapCellValue], mut term_loc: usize) -> usize {
loop {
read_heap_cell!(heap[term_loc],
(HeapCellValueTag::Atom, (_name, arity)) => {
return arity;
}
(HeapCellValueTag::Str, s) => {
term_loc = s;
}
(HeapCellValueTag::Lis) => {
return 2;
}
(HeapCellValueTag::AttrVar | HeapCellValueTag::Var, h) => {
if h != term_loc {
term_loc = h;
} else {
return 0;
}
}
_ => {
return 0;
}
);
}
}
pub fn var_locs_from_iter<I: Iterator<Item = HeapCellValue>>(iter: I) -> VarLocs {
let mut occurrence_set: IndexMap<HeapCellValue, usize, FxBuildHasher> =
IndexMap::with_hasher(FxBuildHasher::default());
for term in iter {
if term.is_var() {
let var_count = occurrence_set.entry(term).or_insert(0);
*var_count += 1;
}
}
VarLocs(
occurrence_set
.into_iter()
.map(|(var, count)| {
let key = var.get_value() as usize;
let queue = if count > 1 {
(0 .. count).map(|_| VarPtr::from(format!("_{}", key))).collect()
} else {
(0 .. count).map(|_| VarPtr::from(Var::Anon)).collect()
};
(key, queue)
})
.collect()
)
}
/*
pub fn term_deref(heap: &[HeapCellValue], mut term_loc: usize) -> HeapCellValue {
loop {
read_heap_cell!(heap[term_loc],
(HeapCellValueTag::AttrVar | HeapCellValueTag::Var, h) => {
if h != term_loc {
term_loc = h;
} else {
return heap[h];
}
}
_ => {
return heap[term_loc];
}
)
}
}
*/
pub fn term_nth_arg(heap: &[HeapCellValue], mut term_loc: usize, n: usize) -> Option<usize> {
loop {
read_heap_cell!(heap[term_loc],
(HeapCellValueTag::Str, s) => {
return if cell_as_atom_cell!(heap[s]).get_arity() >= n {
Some(s+n)
} else {
None
};
}
(HeapCellValueTag::Atom, (_name, arity)) => {
return if arity >= n {
Some(term_loc + n)
} else {
None
};
}
(HeapCellValueTag::Lis, l) => {
return if 1 <= n && n <= 2 {
Some(l+n-1)
} else if n == 0 {
Some(term_loc)
} else {
None
};
}
(HeapCellValueTag::AttrVar | HeapCellValueTag::Var, h) => {
if h != term_loc {
term_loc = h;
} else {
return None;
}
}
_ => {
return None;
}
);
}
}
pub type VarNamesToLocs = IndexMap<String, HeapCellValue, FxBuildHasher>;
#[derive(Debug, Default)]
pub struct VarLocs(IndexMap<usize, VecDeque<VarPtr>, FxBuildHasher>);
impl VarLocs {
pub fn get(&self, key: usize) -> Option<&VarPtr> {
self.0.get(&key)
.and_then(|queue| {
queue.front()
})
}
// if a queue of VarPtr's is stored at location key, pop the front
// if it exists and pass it along to wrapper, returning a value of
// type R. A return value of None indicates that the key doesn't
// exist (the map containing a key necessarily means its queue
// value is non-empty).
fn rotate_latest_mut<R>(
&mut self,
key: usize,
wrapper: impl FnOnce(&VarPtr) -> R,
) -> Option<R> {
self.0.get_mut(&key)
.and_then(move |queue| {
if let Some(var_ptr) = queue.pop_front() {
let result = wrapper(&var_ptr);
queue.push_back(var_ptr);
Some(result)
} else {
None
}
})
}
pub fn peek_next_var_ptr_at_key(&self, key: usize) -> Option<&VarPtr> {
self.0.get(&key).and_then(|queue| queue.front())
}
pub fn read_next_var_ptr_at_key(&mut self, key: usize) -> Option<VarPtr> {
self.rotate_latest_mut(key, VarPtr::clone)
}
pub fn push_at_key(&mut self, key: usize, var_ptr: VarPtr) {
let entry = self.0.entry(key).or_default();
entry.push_back(var_ptr);
}
#[inline]
pub fn iter(&self) -> impl Iterator<Item = (usize, &VecDeque<VarPtr>)> {
self.0.iter().map(|(&k, v)| (k, v))
}
#[inline]
pub fn is_empty(&self) -> bool {
self.0.is_empty()
}
#[inline]
pub fn drain<R>(&mut self, range: R) -> indexmap::map::Drain<usize, VecDeque<VarPtr>>
where R: RangeBounds<usize>
{
self.0.drain(range)
}
#[inline]
pub fn insert(&mut self, key: usize, var_ptrs: VecDeque<VarPtr>) {
self.0.insert(key, var_ptrs);
}
}
#[derive(Debug)]
pub struct FocusedHeap {
pub heap: Vec<HeapCellValue>,
pub focus: usize,
pub var_locs: VarLocs,
}
impl FocusedHeap {
pub fn empty() -> Self {
Self {
heap: vec![],
focus: 0,
var_locs: VarLocs::default(),
}
}
pub fn copy_term_from_machine_heap(
&mut self,
machine_st: &mut MachineState,
cell: HeapCellValue,
) {
let hb = machine_st.heap.len();
copy_term(
CopyBallTerm::new(
&mut machine_st.attr_var_init.attr_var_queue,
&mut machine_st.stack,
&mut machine_st.heap,
&mut self.heap,
),
cell,
AttrVarPolicy::DeepCopy,
);
for cell in self.heap.iter_mut() {
*cell = *cell - hb;
}
}
pub fn as_ref_mut(&mut self, focus: usize) -> FocusedHeapRefMut {
FocusedHeapRefMut {
heap: &mut self.heap,
focus,
// var_locs: &self.var_locs,
}
}
pub fn deref_loc(&self, term_loc: usize) -> HeapCellValue {
use crate::machine::heap::*;
let cell = self.heap[term_loc];
heap_bound_store(&self.heap, heap_bound_deref(&self.heap, cell))
}
pub fn name(&self, term_loc: usize) -> Option<Atom> {
term_name(&self.heap, term_loc)
}
pub fn arity(&self, term_loc: usize) -> usize {
term_arity(&self.heap, term_loc)
}
pub fn nth_arg(&self, term_loc: usize, n: usize) -> Option<usize> {
term_nth_arg(&self.heap, term_loc, n)
}
}
pub struct FocusedHeapRefMut<'a> {
pub heap: &'a mut Vec<HeapCellValue>,
pub focus: usize,
}
impl<'a> FocusedHeapRefMut<'a> {
pub fn name(&self, term_loc: usize) -> Option<Atom> {
term_name(&self.heap, term_loc)
}
pub fn arity(&self, term_loc: usize) -> usize {
term_arity(&self.heap, term_loc)
}
pub fn deref_loc(&self, term_loc: usize) -> HeapCellValue {
use crate::machine::heap::*;
let cell = self.heap[term_loc];
heap_bound_store(&self.heap, heap_bound_deref(&self.heap, cell))
}
pub fn nth_arg(&self, term_loc: usize, n: usize) -> Option<usize> {
term_nth_arg(self.heap, term_loc, n)
}
pub fn from_cell(heap: &'a mut Vec<HeapCellValue>, cell: HeapCellValue) -> Self {
let focus = read_heap_cell!(cell,
(HeapCellValueTag::AttrVar | HeapCellValueTag::Var, h) => {
h
}
_ => {
let h = heap.len();
heap.push(cell);
h
}
);
Self { heap, focus }
}
}