Files
scryer-prolog/src/forms.rs

706 lines
19 KiB
Rust

use crate::prolog_parser::ast::*;
use crate::prolog_parser::parser::OpDesc;
use crate::prolog_parser::tabled_rc::*;
use crate::clause_types::*;
use crate::machine::machine_errors::*;
use crate::machine::machine_indices::*;
use crate::ordered_float::OrderedFloat;
use crate::rug::{Integer, Rational};
use crate::indexmap::IndexMap;
use std::cell::Cell;
use std::collections::VecDeque;
use std::path::PathBuf;
use std::rc::Rc;
pub type PredicateKey = (ClauseName, usize); // name, arity.
// 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>;
#[derive(Debug, Clone)]
pub enum TopLevel {
Declaration(Declaration),
Fact(Term, usize, usize), // Term, line_num, col_num
Predicate(Predicate),
Query(Vec<QueryTerm>),
Rule(Rule, usize, usize), // Rule, line_num, col_num
}
impl TopLevel {
pub fn is_end_of_file_atom(&self) -> bool {
match self {
&TopLevel::Fact(Term::Constant(_, Constant::Atom(ref name, _)), ..) => {
return name.as_str() == "end_of_file"
}
_ => false,
}
}
}
#[derive(Debug, Clone, Copy)]
pub enum Level {
Deep,
Root,
Shallow,
}
impl Level {
pub fn child_level(self) -> Level {
match self {
Level::Root => Level::Shallow,
_ => Level::Deep,
}
}
}
#[derive(Debug, Clone)]
pub 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.
UnblockedCut(Cell<VarReg>),
GetLevelAndUnify(Cell<VarReg>, Rc<Var>),
Jump(JumpStub),
}
impl QueryTerm {
pub 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 {
match self {
&QueryTerm::Clause(_, _, ref subterms, ..) => subterms.len(),
&QueryTerm::BlockedCut | &QueryTerm::UnblockedCut(..) => 0,
&QueryTerm::Jump(ref vars) => vars.len(),
&QueryTerm::GetLevelAndUnify(..) => 1,
}
}
}
#[derive(Debug, Clone)]
pub struct Rule {
pub head: (ClauseName, Vec<Box<Term>>, QueryTerm),
pub clauses: Vec<QueryTerm>,
}
#[derive(Debug, Clone)]
pub struct Predicate(pub Vec<PredicateClause>);
impl Predicate {
#[inline]
pub fn new() -> Self {
Predicate(vec![])
}
#[inline]
pub fn clauses(self) -> Vec<PredicateClause> {
self.0
}
#[inline]
pub fn predicate_indicator(&self) -> Option<(ClauseName, usize)> {
self.0
.first()
.and_then(|clause| clause.name().map(|name| (name, clause.arity())))
}
}
#[derive(Debug, Clone)]
pub enum ListingSource {
File(ClauseName, PathBuf), // filename, path
User,
}
impl ListingSource {
pub fn from_file_and_path(filename: ClauseName, path_buf: PathBuf) -> Self {
ListingSource::File(filename, path_buf)
}
pub fn name(&self) -> ClauseName {
match self {
ListingSource::File(ref filename, _) => filename.clone(),
ListingSource::User => clause_name!("[user]")
}
}
pub fn path(&self) -> PathBuf {
match self {
ListingSource::File(_, ref path) => path.clone(),
ListingSource::User => std::env::current_dir().unwrap(),
}
}
}
fn resolved_term_and_module(term: &Term) -> Option<(ClauseName, ClauseName)>
{
match term {
Term::Clause(_, ref name, ref terms, _) => {
if name.as_str() == ":" && terms.len() == 2 {
let module_name = match terms[0].as_ref() {
&Term::Constant(_, Constant::Atom(ref module_name, _)) => {
module_name.clone()
}
_ => {
return Some((name.owning_module(), name.clone()));
}
};
match terms[1].as_ref() {
Term::Clause(_, ref name, ..)
| Term::Constant(_, Constant::Atom(ref name, ..)) => {
return Some((module_name, name.clone()));
}
_ => {
}
}
Some((name.owning_module(), name.clone()))
} else {
Some((name.owning_module(), name.clone()))
}
}
Term::Constant(_, Constant::Atom(ref name, _)) => {
Some((name.owning_module(), name.clone()))
}
_ => {
None
}
}
}
fn resolved_term_arity(term: &Term) -> usize
{
match term {
Term::Clause(_, ref name, ref terms, _) => {
if name.as_str() == ":" && terms.len() == 2 {
match terms[0].as_ref() {
&Term::Constant(_, Constant::Atom(..)) => {
}
_ => {
return 2;
}
}
match terms[1].as_ref() {
Term::Clause(_, _, ref terms, _) => {
terms.len()
}
Term::Constant(_, Constant::Atom(..)) => {
0
}
_ => {
2
}
}
} else {
terms.len()
}
}
_ => {
0
}
}
}
pub trait ClauseConsistency {
fn is_consistent(&self, clauses: &Vec<PredicateClause>) -> bool {
match clauses.first() {
Some(ref cl) => {
self.name_and_module() == cl.name_and_module() && self.arity() == cl.arity()
}
None => {
true
}
}
}
fn name_and_module(&self) -> Option<(ClauseName, ClauseName)>;
fn arity(&self) -> usize;
}
/* Of course '$current_module$' isn't the name of the current
* module. It'll do if no module is explicitly specified through
* (:)/2.
*/
impl ClauseConsistency for Term {
fn name_and_module(&self) -> Option<(ClauseName, ClauseName)>
{
match self {
Term::Clause(_, ref name, ref terms, _) =>
match name.as_str() {
":-" => {
match terms.len() {
1 => None, // a declaration.
2 => resolved_term_and_module(&terms[0]),
_ => Some((name.owning_module(), clause_name!(":-"))),
}
}
_ => {
resolved_term_and_module(self)
}
},
Term::Constant(_, Constant::Atom(ref name, _)) => {
Some((name.owning_module(), name.clone()))
}
_ => {
None
}
}
}
fn arity(&self) -> usize {
match self {
Term::Clause(_, ref name, ref terms, _) =>
match name.as_str() {
":-" => {
match terms.len() {
1 => 0,
2 => resolved_term_arity(&terms[0]),
_ => terms.len(),
}
}
_ => {
resolved_term_arity(self)
}
},
_ => {
0
}
}
}
}
impl ClauseConsistency for Rule {
fn name_and_module(&self) -> Option<(ClauseName, ClauseName)> {
Some((self.head.0.owning_module(), self.head.0.clone()))
}
fn arity(&self) -> usize {
self.head.1.len()
}
}
impl ClauseConsistency for PredicateClause {
fn name_and_module(&self) -> Option<(ClauseName, ClauseName)> {
match self {
&PredicateClause::Fact(ref term, ..) => {
term.name_and_module()
.map(|(_, name)| (name.owning_module(), name))
}
&PredicateClause::Rule(ref rule, ..) => {
rule.name_and_module()
}
}
}
fn arity(&self) -> usize {
match self {
&PredicateClause::Fact(ref term, ..) => {
term.arity()
}
&PredicateClause::Rule(ref rule, ..) => {
rule.arity()
}
}
}
}
impl ClauseConsistency for Predicate {
fn name_and_module(&self) -> Option<(ClauseName, ClauseName)> {
self.0.first().and_then(|clause| clause.name_and_module())
}
fn arity(&self) -> usize {
self.0.first().map(|clause| clause.arity()).unwrap_or(0)
}
}
pub type CompiledResult = (Predicate, VecDeque<TopLevel>);
#[derive(Debug, Clone)]
pub enum PredicateClause {
Fact(Term, usize, usize), // Term, line number, column number.
Rule(Rule, usize, usize), // Term, line number, column number.
}
impl PredicateClause {
pub fn first_arg(&self) -> Option<&Term> {
match self {
&PredicateClause::Fact(ref term, ..) => term.first_arg(),
&PredicateClause::Rule(ref rule, ..) => rule.head.1.first().map(|bt| bt.as_ref()),
}
}
pub fn arity(&self) -> usize {
match self {
&PredicateClause::Fact(ref term, ..) => {
term.arity()
}
&PredicateClause::Rule(ref rule, ..) => {
if rule.head.0.as_str() == ":" && rule.head.1.len() == 2 {
match (rule.head.1)[0].as_ref() {
&Term::Constant(_, Constant::Atom(..)) => {
}
_ => {
return 2;
}
}
(rule.head.1)[1].arity()
} else {
rule.head.1.len()
}
}
}
}
pub fn name(&self) -> Option<ClauseName> {
match self {
&PredicateClause::Fact(ref term, ..) => term.name(),
&PredicateClause::Rule(ref rule, ..) => Some(rule.head.0.clone()),
}
}
}
#[derive(Debug, Clone)]
pub enum ModuleSource {
Library(ClauseName),
File(ClauseName),
}
impl ModuleSource {
pub fn as_functor_stub(&self) -> MachineStub {
match self {
ModuleSource::Library(ref name) => {
functor!("library", [clause_name(name.clone())])
}
ModuleSource::File(ref name) => {
functor!(clause_name(name.clone()))
}
}
}
}
pub type ScopedPredicateKey = (ClauseName, PredicateKey); // module name, predicate indicator.
#[derive(Debug, Clone)]
pub enum MultiFileIndicator {
LocalScoped(ClauseName, usize), // name, arity
ModuleScoped(ScopedPredicateKey),
}
#[derive(Debug, Clone)]
pub enum Declaration {
Dynamic(ClauseName, usize), // name, arity
EndOfFile,
Hook(CompileTimeHook, PredicateClause, VecDeque<TopLevel>),
ModuleInitialization(Vec<QueryTerm>, VecDeque<TopLevel>), // goal
Module(ModuleDecl),
MultiFile(MultiFileIndicator),
NonCountedBacktracking(ClauseName, usize), // name, arity
Op(OpDecl),
SetPrologFlag(DoubleQuotes),
UseModule(ModuleSource),
UseQualifiedModule(ModuleSource, Vec<ModuleExport>),
}
impl Declaration {
#[inline]
pub fn is_module_decl(&self) -> bool {
if let &Declaration::Module(_) = self {
true
} else {
false
}
}
#[inline]
pub fn is_end_of_file(&self) -> bool {
if let &Declaration::EndOfFile = self {
true
} else {
false
}
}
}
#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
pub struct OpDecl(pub usize, pub Specifier, pub ClauseName);
impl OpDecl {
#[inline]
pub fn name(&self) -> ClauseName {
self.2.clone()
}
#[inline]
pub fn remove(&self, op_dir: &mut OpDir) {
self.insert_into_op_dir(clause_name!(""), op_dir, 0);
}
#[inline]
pub fn fixity(&self) -> Fixity {
match self.1 {
XFY | XFX | YFX => Fixity::In,
XF | YF => Fixity::Post,
FX | FY => Fixity::Pre,
_ => unreachable!()
}
}
pub fn insert_into_op_dir(&self, module: ClauseName, op_dir: &mut OpDir, prec: usize) {
let (spec, name) = (self.1, self.2.clone());
let fixity = self.fixity();
match op_dir.get(&(name.clone(), fixity)) {
Some(cell) => {
cell.shared_op_desc().set(prec, spec);
return;
}
None => {}
}
op_dir.insert((name, fixity), OpDirValue::new(spec, prec, module));
}
pub fn submit(
&self,
module: ClauseName,
existing_desc: Option<OpDesc>,
op_dir: &mut OpDir,
) -> Result<(), SessionError> {
let (prec, spec, name) = (self.0, self.1, self.2.clone());
if is_infix!(spec) {
if let Some(desc) = existing_desc {
if desc.post > 0 {
return Err(SessionError::OpIsInfixAndPostFix(name));
}
}
}
if is_postfix!(spec) {
if let Some(desc) = existing_desc {
if desc.inf > 0 {
return Err(SessionError::OpIsInfixAndPostFix(name));
}
}
}
Ok(self.insert_into_op_dir(module, op_dir, prec))
}
}
pub fn fetch_atom_op_spec(
name: ClauseName,
spec: Option<SharedOpDesc>,
op_dir: &OpDir,
) -> Option<SharedOpDesc> {
fetch_op_spec_from_existing(name.clone(), 1, spec.clone(), op_dir)
.or_else(|| fetch_op_spec_from_existing(name, 2, spec, op_dir))
}
pub fn fetch_op_spec_from_existing(
name: ClauseName,
arity: usize,
spec: Option<SharedOpDesc>,
op_dir: &OpDir,
) -> Option<SharedOpDesc> {
if let Some(ref op_desc) = &spec {
if op_desc.arity() != arity {
/* it's possible to extend operator functors with
* additional terms. When that happens,
* void the op_spec by returning None. */
return None;
}
}
spec.or_else(|| fetch_op_spec(name, arity, op_dir))
}
pub fn fetch_op_spec(
name: ClauseName,
arity: usize,
op_dir: &OpDir,
) -> Option<SharedOpDesc> {
match arity {
2 => op_dir
.get(&(name, Fixity::In))
.and_then(|OpDirValue(spec, _)| {
if spec.prec() > 0 {
Some(spec.clone())
} else {
None
}
}),
1 => {
if let Some(OpDirValue(spec, _)) = op_dir.get(&(name.clone(), Fixity::Pre)) {
if spec.prec() > 0 {
return Some(spec.clone());
}
}
op_dir
.get(&(name, Fixity::Post))
.and_then(|OpDirValue(spec, _)| {
if spec.prec() > 0 {
Some(spec.clone())
} else {
None
}
})
}
_ => {
None
}
}
}
pub type ModuleDir = IndexMap<ClauseName, Module>;
#[derive(Debug, Clone, PartialEq)]
pub enum ModuleExport {
OpDecl(OpDecl),
PredicateKey(PredicateKey),
}
#[derive(Debug, Clone)]
pub struct ModuleDecl {
pub name: ClauseName,
pub exports: Vec<ModuleExport>,
}
#[derive(Debug)]
pub struct Module {
pub atom_tbl: TabledData<Atom>,
pub module_decl: ModuleDecl,
pub code_dir: CodeDir,
pub op_dir: OpDir,
pub term_dir: TermDir, // this contains multifile predicates.
pub term_expansions: (Predicate, VecDeque<TopLevel>),
pub goal_expansions: (Predicate, VecDeque<TopLevel>),
pub user_term_expansions: (Predicate, VecDeque<TopLevel>), // term expansions inherited from the user scope.
pub user_goal_expansions: (Predicate, VecDeque<TopLevel>), // same for goal_expansions.
pub local_term_expansions: (Predicate, VecDeque<TopLevel>), // expansions local to the module.
pub local_goal_expansions: (Predicate, VecDeque<TopLevel>),
pub inserted_expansions: bool, // has the module been successfully inserted into toplevel??
pub is_impromptu_module: bool,
pub listing_src: ListingSource,
}
#[derive(Debug, Clone)]
pub enum Number {
Float(OrderedFloat<f64>),
Integer(Rc<Integer>),
Rational(Rc<Rational>),
Fixnum(isize),
}
impl From<Integer> for Number {
#[inline]
fn from(n: Integer) -> Self {
Number::Integer(Rc::new(n))
}
}
impl From<Rational> for Number {
#[inline]
fn from(n: Rational) -> Self {
Number::Rational(Rc::new(n))
}
}
impl From<isize> for Number {
#[inline]
fn from(n: isize) -> Self {
Number::Fixnum(n)
}
}
impl Default for Number {
fn default() -> Self {
Number::Float(OrderedFloat(0f64))
}
}
impl Into<Constant> for Number {
#[inline]
fn into(self) -> Constant {
match self {
Number::Fixnum(n) => Constant::Fixnum(n),
Number::Integer(n) => Constant::Integer(n),
Number::Float(f) => Constant::Float(f),
Number::Rational(r) => Constant::Rational(r),
}
}
}
impl Into<HeapCellValue> for Number {
#[inline]
fn into(self) -> HeapCellValue {
match self {
Number::Fixnum(n) => HeapCellValue::Addr(Addr::Fixnum(n)),
Number::Integer(n) => HeapCellValue::Integer(n),
Number::Float(f) => HeapCellValue::Addr(Addr::Float(f)),
Number::Rational(r) => HeapCellValue::Rational(r),
}
}
}
impl Number {
#[inline]
pub fn is_positive(&self) -> bool {
match self {
&Number::Fixnum(n) => n > 0,
&Number::Integer(ref n) => &**n > &0,
&Number::Float(OrderedFloat(f)) => f.is_sign_positive(),
&Number::Rational(ref r) => &**r > &0,
}
}
#[inline]
pub fn is_negative(&self) -> bool {
match self {
&Number::Fixnum(n) => n < 0,
&Number::Integer(ref n) => &**n < &0,
&Number::Float(OrderedFloat(f)) => f.is_sign_negative(),
&Number::Rational(ref r) => &**r < &0,
}
}
#[inline]
pub fn is_zero(&self) -> bool {
match self {
&Number::Fixnum(n) => n == 0,
&Number::Integer(ref n) => &**n == &0,
&Number::Float(f) => f == OrderedFloat(0f64),
&Number::Rational(ref r) => &**r == &0,
}
}
#[inline]
pub fn abs(self) -> Self {
match self {
Number::Fixnum(n) =>
if let Some(n) = n.checked_abs() {
Number::from(n)
} else {
Number::from(Integer::from(n).abs())
}
Number::Integer(n) => Number::from(Integer::from(n.abs_ref())),
Number::Float(f) => Number::Float(OrderedFloat(f.abs())),
Number::Rational(r) => Number::from(Rational::from(r.abs_ref())),
}
}
}