659 lines
22 KiB
Rust
659 lines
22 KiB
Rust
use prolog::ast::*;
|
|
use prolog::machine::*;
|
|
use prolog::num::*;
|
|
use prolog::parser::parser::*;
|
|
use prolog::tabled_rc::*;
|
|
|
|
use std::collections::{HashSet, VecDeque};
|
|
use std::cell::{Cell, RefCell};
|
|
use std::io::Read;
|
|
use std::mem;
|
|
use std::rc::Rc;
|
|
|
|
fn setup_fact(term: Term) -> Result<Term, ParserError>
|
|
{
|
|
match term {
|
|
Term::Clause(..) | Term::Constant(_, Constant::Atom(_)) =>
|
|
Ok(term),
|
|
_ =>
|
|
Err(ParserError::InadmissibleFact)
|
|
}
|
|
}
|
|
|
|
fn setup_op_decl(mut terms: Vec<Box<Term>>) -> Result<OpDecl, ParserError>
|
|
{
|
|
let name = match *terms.pop().unwrap() {
|
|
Term::Constant(_, Constant::Atom(name)) => name,
|
|
_ => return Err(ParserError::InconsistentEntry)
|
|
};
|
|
|
|
let spec = match *terms.pop().unwrap() {
|
|
Term::Constant(_, Constant::Atom(name)) => name,
|
|
_ => return Err(ParserError::InconsistentEntry)
|
|
};
|
|
|
|
let prec = match *terms.pop().unwrap() {
|
|
Term::Constant(_, Constant::Number(Number::Integer(bi))) =>
|
|
match bi.to_usize() {
|
|
Some(n) if n <= 1200 => n,
|
|
_ => return Err(ParserError::InconsistentEntry)
|
|
},
|
|
_ => return Err(ParserError::InconsistentEntry)
|
|
};
|
|
|
|
match spec.as_str() {
|
|
"xfx" => Ok(OpDecl(prec, XFX, name)),
|
|
"xfy" => Ok(OpDecl(prec, XFY, name)),
|
|
"yfx" => Ok(OpDecl(prec, YFX, name)),
|
|
"fx" => Ok(OpDecl(prec, FX, name)),
|
|
"fy" => Ok(OpDecl(prec, FY, name)),
|
|
"xf" => Ok(OpDecl(prec, XF, name)),
|
|
"yf" => Ok(OpDecl(prec, YF, name)),
|
|
_ => Err(ParserError::InconsistentEntry)
|
|
}
|
|
}
|
|
|
|
fn setup_predicate_export(mut term: Term) -> Result<PredicateKey, ParserError>
|
|
{
|
|
match term {
|
|
Term::Clause(_, ref name, ref mut terms, Some(Fixity::In))
|
|
if name.as_str() == "/" && terms.len() == 2 => {
|
|
let arity = *terms.pop().unwrap();
|
|
let name = *terms.pop().unwrap();
|
|
|
|
let arity = arity.to_constant().and_then(|c| c.to_integer())
|
|
.and_then(|n| if !n.is_negative() { n.to_usize() } else { None })
|
|
.ok_or(ParserError::InvalidModuleExport)?;
|
|
|
|
let name = name.to_constant().and_then(|c| c.to_atom())
|
|
.ok_or(ParserError::InvalidModuleExport)?;
|
|
|
|
Ok((name, arity))
|
|
},
|
|
_ => Err(ParserError::InvalidModuleExport)
|
|
}
|
|
}
|
|
|
|
fn setup_module_decl(mut terms: Vec<Box<Term>>) -> Result<ModuleDecl, ParserError>
|
|
{
|
|
let mut export_list = *terms.pop().unwrap();
|
|
let name = terms.pop().unwrap().to_constant().and_then(|c| c.to_atom())
|
|
.ok_or(ParserError::InvalidModuleDecl)?;
|
|
|
|
let mut exports = Vec::new();
|
|
|
|
while let Term::Cons(_, t1, t2) = export_list {
|
|
exports.push(setup_predicate_export(*t1)?);
|
|
export_list = *t2;
|
|
}
|
|
|
|
if export_list.to_constant() != Some(Constant::EmptyList) {
|
|
Err(ParserError::InvalidModuleDecl)
|
|
} else {
|
|
Ok(ModuleDecl { name, exports })
|
|
}
|
|
}
|
|
|
|
fn setup_use_module_decl(mut terms: Vec<Box<Term>>) -> Result<ClauseName, ParserError>
|
|
{
|
|
match *terms.pop().unwrap() {
|
|
Term::Clause(_, ref name, ref mut terms, None)
|
|
if name.as_str() == "library" && terms.len() == 1 => {
|
|
terms.pop().unwrap().to_constant()
|
|
.and_then(|c| c.to_atom())
|
|
.ok_or(ParserError::InvalidUseModuleDecl)
|
|
},
|
|
_ => Err(ParserError::InvalidUseModuleDecl)
|
|
}
|
|
}
|
|
|
|
type UseModuleExport = (ClauseName, Vec<PredicateKey>);
|
|
|
|
fn setup_qualified_import(mut terms: Vec<Box<Term>>) -> Result<UseModuleExport, ParserError>
|
|
{
|
|
let mut export_list = *terms.pop().unwrap();
|
|
let name = match *terms.pop().unwrap() {
|
|
Term::Clause(_, ref name, ref mut terms, None)
|
|
if name.as_str() == "library" && terms.len() == 1 => {
|
|
terms.pop().unwrap().to_constant()
|
|
.and_then(|c| c.to_atom())
|
|
.ok_or(ParserError::InvalidUseModuleDecl)
|
|
},
|
|
_ => Err(ParserError::InvalidUseModuleDecl)
|
|
}?;
|
|
|
|
let mut exports = Vec::new();
|
|
|
|
while let Term::Cons(_, t1, t2) = export_list {
|
|
exports.push(setup_predicate_export(*t1)?);
|
|
export_list = *t2;
|
|
}
|
|
|
|
if export_list.to_constant() != Some(Constant::EmptyList) {
|
|
Err(ParserError::InvalidModuleDecl)
|
|
} else {
|
|
Ok((name, exports))
|
|
}
|
|
}
|
|
|
|
fn setup_declaration(term: Term) -> Result<Declaration, ParserError>
|
|
{
|
|
match term {
|
|
Term::Clause(_, name, terms, _) =>
|
|
if name.as_str() == "op" && terms.len() == 3 {
|
|
Ok(Declaration::Op(setup_op_decl(terms)?))
|
|
} else if name.as_str() == "module" && terms.len() == 2 {
|
|
Ok(Declaration::Module(setup_module_decl(terms)?))
|
|
} else if name.as_str() == "use_module" && terms.len() == 1 {
|
|
Ok(Declaration::UseModule(setup_use_module_decl(terms)?))
|
|
} else if name.as_str() == "use_module" && terms.len() == 2 {
|
|
let (name, exports) = setup_qualified_import(terms)?;
|
|
Ok(Declaration::UseQualifiedModule(name, exports))
|
|
} else {
|
|
Err(ParserError::InconsistentEntry)
|
|
},
|
|
_ => return Err(ParserError::InconsistentEntry)
|
|
}
|
|
}
|
|
|
|
fn is_consistent(tl: &TopLevel, clauses: &Vec<PredicateClause>) -> bool
|
|
{
|
|
match clauses.first() {
|
|
Some(ref cl) => tl.name() == cl.name() && tl.arity() == cl.arity(),
|
|
None => true
|
|
}
|
|
}
|
|
|
|
fn deque_to_packet(head: TopLevel, deque: VecDeque<TopLevel>) -> TopLevelPacket
|
|
{
|
|
match head {
|
|
TopLevel::Query(query) => TopLevelPacket::Query(query, Vec::from(deque)),
|
|
tl => TopLevelPacket::Decl(tl, Vec::from(deque))
|
|
}
|
|
}
|
|
|
|
fn merge_clauses(tls: &mut VecDeque<TopLevel>) -> Result<TopLevel, ParserError>
|
|
{
|
|
let mut clauses: Vec<PredicateClause> = vec![];
|
|
|
|
while let Some(tl) = tls.pop_front() {
|
|
match tl {
|
|
TopLevel::Query(_) if clauses.is_empty() && tls.is_empty() =>
|
|
return Ok(tl),
|
|
TopLevel::Declaration(_) if clauses.is_empty() =>
|
|
return Ok(tl),
|
|
TopLevel::Query(_) =>
|
|
return Err(ParserError::InconsistentEntry),
|
|
TopLevel::Fact(_) if is_consistent(&tl, &clauses) =>
|
|
if let TopLevel::Fact(fact) = tl {
|
|
let clause = PredicateClause::Fact(fact);
|
|
clauses.push(clause);
|
|
},
|
|
TopLevel::Rule(_) if is_consistent(&tl, &clauses) =>
|
|
if let TopLevel::Rule(rule) = tl {
|
|
let clause = PredicateClause::Rule(rule);
|
|
clauses.push(clause);
|
|
},
|
|
TopLevel::Predicate(_) if is_consistent(&tl, &clauses) =>
|
|
if let TopLevel::Predicate(pred) = tl {
|
|
clauses.extend(pred.clauses().into_iter())
|
|
},
|
|
_ => {
|
|
tls.push_front(tl);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if clauses.is_empty() {
|
|
Err(ParserError::InconsistentEntry)
|
|
} else {
|
|
Ok(TopLevel::Predicate(Predicate(clauses)))
|
|
}
|
|
}
|
|
|
|
fn append_preds(preds: &mut Vec<PredicateClause>) -> Predicate {
|
|
Predicate(mem::replace(preds, vec![]))
|
|
}
|
|
|
|
fn unfold_by_str_once(term: &mut Term, s: &str) -> Option<(Term, Term)>
|
|
{
|
|
if let &mut Term::Clause(_, ref name, ref mut subterms, _) = term {
|
|
if name.as_str() == s && subterms.len() == 2 {
|
|
let snd = *subterms.pop().unwrap();
|
|
let fst = *subterms.pop().unwrap();
|
|
|
|
return Some((fst, snd));
|
|
}
|
|
}
|
|
|
|
None
|
|
}
|
|
|
|
fn unfold_by_str(mut term: Term, s: &str) -> 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
|
|
}
|
|
|
|
fn fold_by_str(mut terms: Vec<Term>, mut term: Term, sym: ClauseName) -> Term
|
|
{
|
|
while let Some(prec) = terms.pop() {
|
|
term = Term::Clause(Cell::default(), sym.clone(),
|
|
vec![Box::new(prec), Box::new(term)],
|
|
None);
|
|
}
|
|
|
|
term
|
|
}
|
|
|
|
fn mark_cut_variables_as(terms: &mut Vec<Term>, name: ClauseName) {
|
|
for term in terms.iter_mut() {
|
|
match term {
|
|
&mut Term::Constant(_, Constant::Atom(ref mut var)) if var.as_str() == "!" =>
|
|
*var = name.clone(),
|
|
_ => {}
|
|
}
|
|
}
|
|
}
|
|
|
|
fn mark_cut_variable(term: &mut Term) -> bool {
|
|
let cut_var_found = match term {
|
|
&mut Term::Constant(_, Constant::Atom(ref var)) if var.as_str() == "!" => true,
|
|
_ => false
|
|
};
|
|
|
|
if cut_var_found {
|
|
*term = Term::Var(Cell::default(), rc_atom!("!"));
|
|
true
|
|
} else {
|
|
false
|
|
}
|
|
}
|
|
|
|
fn mark_cut_variables(terms: &mut Vec<Term>) -> bool {
|
|
let mut found_cut_var = false;
|
|
|
|
for item in terms.iter_mut() {
|
|
found_cut_var = mark_cut_variable(item);
|
|
}
|
|
|
|
found_cut_var
|
|
}
|
|
|
|
fn module_resolution_call(mod_name: Term, body: Term) -> Result<QueryTerm, ParserError> {
|
|
if let Term::Constant(_, Constant::Atom(mod_name)) = mod_name {
|
|
if let Term::Clause(_, name, terms, _) = body {
|
|
let idx = CodeIndex(Rc::new(RefCell::new((IndexPtr::Module, mod_name))));
|
|
return Ok(QueryTerm::Clause(Cell::default(), ClauseType::Named(name, idx), terms));
|
|
}
|
|
}
|
|
|
|
Err(ParserError::InvalidModuleResolution)
|
|
}
|
|
|
|
pub enum TopLevelPacket {
|
|
Query(Vec<QueryTerm>, Vec<TopLevel>),
|
|
Decl(TopLevel, Vec<TopLevel>)
|
|
}
|
|
|
|
struct RelationWorker {
|
|
queue: VecDeque<VecDeque<Term>>
|
|
}
|
|
|
|
impl RelationWorker {
|
|
fn new() -> Self {
|
|
RelationWorker { queue: VecDeque::new() }
|
|
}
|
|
|
|
fn compute_head(&self, term: &Term) -> Vec<Term>
|
|
{
|
|
let mut vars = HashSet::new();
|
|
|
|
for term in term.post_order_iter() {
|
|
if let TermRef::Var(_, _, v) = term {
|
|
vars.insert(v.clone());
|
|
}
|
|
}
|
|
|
|
vars.insert(rc_atom!("!"));
|
|
vars.into_iter()
|
|
.map(|v| Term::Var(Cell::default(), v))
|
|
.collect()
|
|
}
|
|
|
|
fn fabricate_rule_body(&self, vars: &Vec<Term>, body_term: Term) -> Term
|
|
{
|
|
let vars_of_head = vars.iter().cloned().map(Box::new).collect();
|
|
let head_term = Term::Clause(Cell::default(), clause_name!(""), vars_of_head, None);
|
|
|
|
let rule = vec![Box::new(head_term), Box::new(body_term)];
|
|
let turnstile = clause_name!(":-");
|
|
|
|
Term::Clause(Cell::default(), turnstile, rule, None)
|
|
}
|
|
|
|
// the terms form the body of the rule. We create a head, by
|
|
// gathering variables from the body of terms and recording them
|
|
// in the head clause.
|
|
fn fabricate_rule(&self, body_term: Term) -> (JumpStub, VecDeque<Term>)
|
|
{
|
|
// collect the vars of body_term into a head, return the num_vars
|
|
// (the arity) as well.
|
|
let vars = self.compute_head(&body_term);
|
|
let rule = self.fabricate_rule_body(&vars, body_term);
|
|
|
|
(vars, VecDeque::from(vec![rule]))
|
|
}
|
|
|
|
fn fabricate_disjunct(&self, body_term: Term) -> (JumpStub, VecDeque<Term>)
|
|
{
|
|
let mut cut_var_found = false;
|
|
|
|
let mut vars = self.compute_head(&body_term);
|
|
let clauses: Vec<_> = unfold_by_str(body_term, ";").into_iter()
|
|
.map(|term| {
|
|
let mut subterms = unfold_by_str(term, ",");
|
|
cut_var_found = mark_cut_variables(&mut subterms);
|
|
|
|
let term = subterms.pop().unwrap();
|
|
fold_by_str(subterms, term, clause_name!(","))
|
|
}).collect();
|
|
|
|
if cut_var_found {
|
|
vars.push(Term::Var(Cell::default(), rc_atom!("!")));
|
|
}
|
|
|
|
let results = clauses.into_iter()
|
|
.map(|clause| self.fabricate_rule_body(&vars, clause))
|
|
.collect();
|
|
|
|
(vars, results)
|
|
}
|
|
|
|
fn fabricate_if_then(&self, prec: Term, conq: Term) -> (JumpStub, VecDeque<Term>)
|
|
{
|
|
let mut prec_seq = unfold_by_str(prec, ",");
|
|
let comma_sym = clause_name!(",");
|
|
let cut_sym = atom!("!");
|
|
|
|
prec_seq.push(Term::Constant(Cell::default(), cut_sym));
|
|
|
|
mark_cut_variables_as(&mut prec_seq, clause_name!("blocked_!"));
|
|
|
|
let mut conq_seq = unfold_by_str(conq, ",");
|
|
|
|
mark_cut_variables(&mut conq_seq);
|
|
prec_seq.extend(conq_seq.into_iter());
|
|
|
|
let back_term = Box::new(prec_seq.pop().unwrap());
|
|
let front_term = Box::new(prec_seq.pop().unwrap());
|
|
|
|
let body_term = Term::Clause(Cell::default(), comma_sym.clone(),
|
|
vec![front_term, back_term], None);
|
|
|
|
self.fabricate_rule(fold_by_str(prec_seq, body_term, comma_sym))
|
|
}
|
|
|
|
fn to_query_term(&mut self, indices: &mut MachineCodeIndices, term: Term)
|
|
-> Result<QueryTerm, ParserError>
|
|
{
|
|
match term {
|
|
Term::Constant(r, Constant::Atom(name)) =>
|
|
if name.as_str() == "!" || name.as_str() == "blocked_!" {
|
|
Ok(QueryTerm::BlockedCut)
|
|
} else {
|
|
let ct = indices.lookup(name, 0, None);
|
|
Ok(QueryTerm::Clause(r, ct, vec![]))
|
|
},
|
|
Term::Var(_, ref v) if v.as_str() == "!" =>
|
|
Ok(QueryTerm::UnblockedCut(Cell::default())),
|
|
Term::Clause(r, name, mut terms, fixity) =>
|
|
if name.as_str() == ";" && terms.len() == 2 {
|
|
let term = Term::Clause(r, name.clone(), terms, fixity);
|
|
let (stub, clauses) = self.fabricate_disjunct(term);
|
|
|
|
self.queue.push_back(clauses);
|
|
Ok(QueryTerm::Jump(stub))
|
|
} else if name.as_str() == ":" && terms.len() == 2 {
|
|
let callee = *terms.pop().unwrap();
|
|
let mod_name = *terms.pop().unwrap();
|
|
|
|
module_resolution_call(mod_name, callee)
|
|
} else if name.as_str() == "->" && terms.len() == 2 {
|
|
let conq = *terms.pop().unwrap();
|
|
let prec = *terms.pop().unwrap();
|
|
|
|
let (stub, clauses) = self.fabricate_if_then(prec, conq);
|
|
|
|
self.queue.push_back(clauses);
|
|
Ok(QueryTerm::Jump(stub))
|
|
} else if name.as_str() == "$get_level" && terms.len() == 1 {
|
|
if let Term::Var(_, ref var) = *terms[0] {
|
|
Ok(QueryTerm::GetLevelAndUnify(Cell::default(), var.clone()))
|
|
} else {
|
|
Err(ParserError::InadmissibleQueryTerm)
|
|
}
|
|
} else {
|
|
let ct = indices.lookup(name, terms.len(), fixity);
|
|
Ok(QueryTerm::Clause(Cell::default(), ct, terms))
|
|
},
|
|
Term::Var(_, _) =>
|
|
Ok(QueryTerm::Clause(Cell::default(), ClauseType::CallN, vec![Box::new(term)])),
|
|
_ =>
|
|
Err(ParserError::InadmissibleQueryTerm)
|
|
}
|
|
}
|
|
|
|
// never blocks cuts in the consequent.
|
|
fn prepend_if_then(&self, prec: Term, conq: Term, queue: &mut VecDeque<Box<Term>>,
|
|
blocks_cuts: bool)
|
|
{
|
|
let cut_symb = atom!("blocked_!");
|
|
let mut terms_seq = unfold_by_str(prec, ",");
|
|
|
|
terms_seq.push(Term::Constant(Cell::default(), cut_symb));
|
|
|
|
let mut conq_seq = unfold_by_str(conq, ",");
|
|
|
|
if !blocks_cuts {
|
|
for item in conq_seq.iter_mut() {
|
|
mark_cut_variable(item);
|
|
}
|
|
}
|
|
|
|
terms_seq.append(&mut conq_seq);
|
|
|
|
while let Some(term) = terms_seq.pop() {
|
|
queue.push_front(Box::new(term));
|
|
}
|
|
}
|
|
|
|
fn setup_query(&mut self, idx: &mut MachineCodeIndices, terms: Vec<Box<Term>>, blocks_cuts: bool)
|
|
-> Result<Vec<QueryTerm>, ParserError>
|
|
{
|
|
let mut query_terms = vec![];
|
|
let mut work_queue = VecDeque::from(terms);
|
|
|
|
while let Some(term) = work_queue.pop_front() {
|
|
let mut term = *term;
|
|
|
|
// a (->) clause makes up the entire query. That's what the test confirms.
|
|
if query_terms.is_empty() && work_queue.is_empty() {
|
|
// check for ->, inline it if found.
|
|
if let &mut Term::Clause(_, ref name, ref mut subterms, _) = &mut term {
|
|
if name.as_str() == "->" && subterms.len() == 2 {
|
|
let conq = *subterms.pop().unwrap();
|
|
let prec = *subterms.pop().unwrap();
|
|
|
|
self.prepend_if_then(prec, conq, &mut work_queue, blocks_cuts);
|
|
continue;
|
|
}
|
|
}
|
|
}
|
|
|
|
for mut subterm in unfold_by_str(term, ",") {
|
|
if !blocks_cuts {
|
|
mark_cut_variable(&mut subterm);
|
|
}
|
|
|
|
query_terms.push(try!(self.to_query_term(idx, subterm)));
|
|
}
|
|
}
|
|
|
|
Ok(query_terms)
|
|
}
|
|
|
|
fn setup_rule(&mut self, idx: &mut MachineCodeIndices, mut terms: Vec<Box<Term>>, blocks_cuts: bool)
|
|
-> Result<Rule, ParserError>
|
|
{
|
|
let post_head_terms = terms.drain(1..).collect();
|
|
let mut query_terms = try!(self.setup_query(idx, post_head_terms, blocks_cuts));
|
|
let clauses = query_terms.drain(1 ..).collect();
|
|
let qt = query_terms.pop().unwrap();
|
|
|
|
match *terms.pop().unwrap() {
|
|
Term::Clause(_, name, terms, _) =>
|
|
Ok(Rule { head: (name, terms, qt), clauses }),
|
|
Term::Constant(_, Constant::Atom(name)) =>
|
|
Ok(Rule { head: (name, vec![], qt), clauses }),
|
|
_ => Err(ParserError::InvalidRuleHead)
|
|
}
|
|
}
|
|
|
|
fn try_term_to_tl(&mut self, idx: &mut MachineCodeIndices, term: Term, blocks_cuts: bool)
|
|
-> Result<TopLevel, ParserError>
|
|
{
|
|
match term {
|
|
Term::Clause(r, name, mut terms, fixity) =>
|
|
if name.as_str() == "?-" {
|
|
Ok(TopLevel::Query(try!(self.setup_query(idx, terms, blocks_cuts))))
|
|
} else if name.as_str() == ":-" && terms.len() > 1 {
|
|
Ok(TopLevel::Rule(try!(self.setup_rule(idx, terms, blocks_cuts))))
|
|
} else if name.as_str() == ":-" && terms.len() == 1 {
|
|
let term = *terms.pop().unwrap();
|
|
Ok(TopLevel::Declaration(try!(setup_declaration(term))))
|
|
} else {
|
|
Ok(TopLevel::Fact(try!(setup_fact(Term::Clause(r, name, terms, fixity)))))
|
|
},
|
|
term => Ok(TopLevel::Fact(try!(setup_fact(term))))
|
|
}
|
|
}
|
|
|
|
fn try_terms_to_tls<Iter>(&mut self, idx: &mut MachineCodeIndices, terms: Iter, blocks_cuts: bool)
|
|
-> Result<VecDeque<TopLevel>, ParserError>
|
|
where Iter: IntoIterator<Item=Term>
|
|
{
|
|
let mut results = VecDeque::new();
|
|
|
|
for term in terms.into_iter() {
|
|
results.push_back(self.try_term_to_tl(idx, term, blocks_cuts)?);
|
|
}
|
|
|
|
Ok(results)
|
|
}
|
|
|
|
fn parse_queue(&mut self, idx: &mut MachineCodeIndices) -> Result<VecDeque<TopLevel>, ParserError>
|
|
{
|
|
let mut queue = VecDeque::new();
|
|
|
|
while let Some(terms) = self.queue.pop_front() {
|
|
let clauses = merge_clauses(&mut self.try_terms_to_tls(idx, terms, false)?)?;
|
|
queue.push_back(clauses);
|
|
}
|
|
|
|
Ok(queue)
|
|
}
|
|
|
|
fn absorb(&mut self, other: RelationWorker) {
|
|
self.queue.extend(other.queue.into_iter());
|
|
}
|
|
}
|
|
|
|
pub struct TopLevelWorker<'a, R: Read> {
|
|
pub parser: Parser<R>,
|
|
indices: MachineCodeIndices<'a>
|
|
}
|
|
|
|
impl<'a, R: Read> TopLevelWorker<'a, R> {
|
|
pub fn new(inner: R, atom_tbl: TabledData<Atom>, indices: MachineCodeIndices<'a>) -> Self {
|
|
TopLevelWorker { parser: Parser::new(inner, atom_tbl), indices }
|
|
}
|
|
|
|
pub fn parse_code(&mut self) -> Result<TopLevelPacket, ParserError>
|
|
{
|
|
let mut rel_worker = RelationWorker::new();
|
|
|
|
let terms = self.parser.read(self.indices.op_dir)?;
|
|
let mut tls = rel_worker.try_terms_to_tls(&mut self.indices, terms, true)?;
|
|
let results = rel_worker.parse_queue(&mut self.indices)?;
|
|
|
|
let tl = merge_clauses(&mut tls)?;
|
|
|
|
if tls.is_empty() {
|
|
Ok(deque_to_packet(tl, results))
|
|
} else {
|
|
Err(ParserError::InconsistentEntry)
|
|
}
|
|
}
|
|
}
|
|
|
|
pub struct TopLevelBatchWorker<R: Read> {
|
|
parser: Parser<R>,
|
|
rel_worker: RelationWorker,
|
|
pub source_mod: ClauseName,
|
|
pub results: Vec<(Predicate, VecDeque<TopLevel>)>
|
|
}
|
|
|
|
impl<R: Read> TopLevelBatchWorker<R> {
|
|
pub fn new(inner: R, atom_tbl: TabledData<Atom>) -> Self {
|
|
TopLevelBatchWorker { parser: Parser::new(inner, atom_tbl),
|
|
rel_worker: RelationWorker::new(),
|
|
source_mod: clause_name!("user"),
|
|
results: vec![] }
|
|
}
|
|
|
|
pub
|
|
fn consume(&mut self, indices: &mut MachineCodeIndices) -> Result<Option<Declaration>, SessionError>
|
|
{
|
|
let mut preds = vec![];
|
|
|
|
while !self.parser.eof() {
|
|
self.parser.reset(); // empty the parser stack of token descriptions.
|
|
|
|
let mut new_rel_worker = RelationWorker::new();
|
|
let term = self.parser.read_term(&indices.op_dir)?;
|
|
let tl = new_rel_worker.try_term_to_tl(indices, term, true)?;
|
|
|
|
if !is_consistent(&tl, &preds) { // if is_consistent returns false, preds is non-empty.
|
|
let result_queue = self.rel_worker.parse_queue(indices)?;
|
|
self.results.push((append_preds(&mut preds), result_queue));
|
|
}
|
|
|
|
self.rel_worker.absorb(new_rel_worker);
|
|
|
|
match tl {
|
|
TopLevel::Fact(fact) => preds.push(PredicateClause::Fact(fact)),
|
|
TopLevel::Rule(rule) => preds.push(PredicateClause::Rule(rule)),
|
|
TopLevel::Predicate(pred) => preds.extend(pred.0),
|
|
TopLevel::Declaration(decl) => return Ok(Some(decl)),
|
|
TopLevel::Query(_) => return Err(SessionError::NamelessEntry)
|
|
}
|
|
}
|
|
|
|
if !preds.is_empty() {
|
|
let result_queue = self.rel_worker.parse_queue(indices)?;
|
|
self.results.push((append_preds(&mut preds), result_queue));
|
|
}
|
|
|
|
Ok(None)
|
|
}
|
|
}
|