rishi/scryer-prolog
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fix faulty chunking on call/N.

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This commit is contained in:
Mark Thom
2017-08-03 10:55:43 -06:00
parent 315c748c31
commit 409d79719d
4 changed files with 45 additions and 27 deletions
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5
src/main.rs
View File

@@ -549,7 +549,7 @@ mod tests {
submit(&mut wam, "maplist(Pred, []).
maplist(Pred, [X|Xs]) :- call(Pred, X), maplist(Pred, Xs).");
submit(&mut wam, "f(a). f(b). f(c).");
assert_eq!(submit(&mut wam, "?- maplist(f, [X,Y,Z])."), true);
assert_eq!(submit(&mut wam, "?- maplist(f, [a,Y,Z])."), true);
assert_eq!(submit(&mut wam, "?- maplist(f, [X,a,b])."), true);
@@ -647,6 +647,9 @@ mod tests {
assert_eq!(submit(&mut wam, "?- call_mult(p(two), one)."), false);
assert_eq!(submit(&mut wam, "?- call_mult(p(two), two)."), true);
assert_eq!(submit(&mut wam, "?- call(call(p(one)), X), call(call(p(two)), two)."), true);
assert_eq!(submit(&mut wam, "?- call(call(p(one)), X), call(call(p(two)), one)."), false);
submit(&mut wam, "f(call(f, undefined)). f(undefined).");
submit(&mut wam, "call_var(P) :- P.");

3
src/prolog/io.rs
View File

@@ -301,6 +301,7 @@ pub fn eval<'a, 'b: 'a>(wam: &'a mut Machine, tl: &'b TopLevel) -> EvalSession<'
if is_consistent(clauses) {
let compiled_pred = cg.compile_predicate(clauses);
print_code(&compiled_pred);
wam.add_predicate(clauses, compiled_pred)
} else {
let msg = r"Error: predicate is inconsistent.
@@ -319,12 +320,14 @@ Each predicate must have the same name and arity.";
let mut cg = CodeGenerator::<DebrayAllocator>::new();
let compiled_rule = cg.compile_rule(rule);
print_code(&compiled_rule);
wam.add_rule(rule, compiled_rule)
},
&TopLevel::Query(ref query) => {
let mut cg = CodeGenerator::<DebrayAllocator>::new();
let compiled_query = cg.compile_query(query);
print_code(&compiled_query);
wam.submit_query(compiled_query, cg.take_vars())
}
}

4
src/prolog/iterators.rs
View File

@@ -285,7 +285,7 @@ impl<'a> ChunkedIterator<'a>
result.push(term);
arity = child_terms.len() + 1;
break;
},
},
_ => {
result.push(term);
self.deep_cut_encountered = true;
@@ -312,6 +312,8 @@ impl<'a> Iterator for ChunkedIterator<'a>
},
Some(QueryTermRef::Term(term)) if term.is_callable() =>
return Some((term.arity(), vec![QueryTermRef::Term(term)])),
Some(QueryTermRef::CallN(child_terms)) =>
return Some((child_terms.len() + 1, vec![QueryTermRef::CallN(child_terms)])),
Some(term_or_cut_ref) =>
return Some(self.take_chunk(term_or_cut_ref))
}

60
src/prolog/machine.rs
View File

@@ -33,7 +33,6 @@ struct MachineState {
trail: Vec<Ref>,
tr: usize,
hb: usize,
lco: bool
}
#[derive(Clone, Copy, PartialEq, Eq, Hash)]
@@ -98,7 +97,8 @@ impl Index<CodePtr> for Machine {
impl Machine {
pub fn new() -> Self {
let mut code_dir = HashMap::new();
let code = vec![Line::BuiltIn(BuiltInInstruction::InternalCallN)];
let code = vec![Line::BuiltIn(BuiltInInstruction::InternalCallN),
Line::Control(ControlInstruction::Proceed)];
// there are 64 registers in the VM, so call/N is defined for all 0 <= N <= 63
// (an extra register is needed for the predicate name)
@@ -450,7 +450,6 @@ impl MachineState {
trail: Vec::new(),
tr: 0,
hb: 0,
lco: false
}
}
@@ -993,22 +992,27 @@ impl MachineState {
}
}
fn try_call_predicate(&mut self, code_dir: &CodeDir, name: Atom, arity: usize, lco: bool)
fn try_call_predicate(&mut self, code_dir: &CodeDir, name: Atom, arity: usize)
{
let compiled_tl_index = code_dir.get(&(name, arity)).map(|index| index.1);
let compiled_tl_index = code_dir.get(&(name, arity)).map(|index| index.1);
match compiled_tl_index {
Some(compiled_tl_index) if lco => {
self.lco = true;
Some(compiled_tl_index) => {
self.cp = self.p + 1;
self.num_of_args = arity;
self.b0 = self.b;
self.p = CodePtr::DirEntry(compiled_tl_index);
},
None => self.fail = true
};
}
fn try_execute_predicate(&mut self, code_dir: &CodeDir, name: Atom, arity: usize)
{
let compiled_tl_index = code_dir.get(&(name, arity)).map(|index| index.1);
match compiled_tl_index {
Some(compiled_tl_index) => {
self.lco = false;
self.cp = self.p + 1;
self.num_of_args = arity;
self.b0 = self.b;
self.p = CodePtr::DirEntry(compiled_tl_index);
@@ -1020,7 +1024,6 @@ impl MachineState {
fn handle_internal_call_n(&mut self, code_dir: &CodeDir)
{
let arity = self.num_of_args + 1;
let lco = self.lco;
let pred = self.registers[1].clone();
for i in 2 .. arity {
@@ -1029,15 +1032,18 @@ impl MachineState {
if arity > 1 {
self.registers[arity - 1] = pred;
self.execute_call_n(code_dir, arity - 1, lco);
if let Some((name, arity)) = self.setup_call_n(arity - 1) {
self.try_execute_predicate(code_dir, name, arity);
}
} else {
self.fail = true;
}
}
fn execute_call_n(&mut self, code_dir: &CodeDir, arity: usize, lco: bool)
fn setup_call_n(&mut self, arity: usize) -> Option<PredicateKey>
{
let addr = self.deref(self.registers[arity].clone());
let addr = self.deref(self.registers[arity].clone());
let (name, narity) = match self.store(addr) {
Addr::Str(a) => {
@@ -1055,17 +1061,17 @@ impl MachineState {
(name, narity)
} else {
self.fail = true;
return;
return None;
}
},
Addr::Con(Constant::Atom(name)) => (name, 0),
_ => {
self.fail = true;
return;
return None;
}
};
self.try_call_predicate(code_dir, name, arity + narity - 1, lco);
Some((name, arity + narity - 1))
}
fn execute_ctrl_instr(&mut self, code_dir: &CodeDir, instr: &ControlInstruction)
@@ -1080,9 +1086,11 @@ impl MachineState {
self.p += 1;
},
&ControlInstruction::Call(ref name, arity, _) =>
self.try_call_predicate(code_dir, name.clone(), arity, false),
self.try_call_predicate(code_dir, name.clone(), arity),
&ControlInstruction::CallN(arity) =>
self.execute_call_n(code_dir, arity, false),
if let Some((name, arity)) = self.setup_call_n(arity) {
self.try_call_predicate(code_dir, name, arity);
},
&ControlInstruction::Deallocate => {
let e = self.e;
@@ -1091,10 +1099,12 @@ impl MachineState {
self.p += 1;
},
&ControlInstruction::Execute(ref name, arity) =>
self.try_call_predicate(code_dir, name.clone(), arity, true),
&ControlInstruction::Execute(ref name, arity) =>
self.try_execute_predicate(code_dir, name.clone(), arity),
&ControlInstruction::ExecuteN(arity) =>
self.execute_call_n(code_dir, arity, true),
if let Some((name, arity)) = self.setup_call_n(arity) {
self.try_execute_predicate(code_dir, name, arity);
},
&ControlInstruction::Proceed =>
self.p = self.cp,
};
@@ -1189,7 +1199,7 @@ impl MachineState {
fn execute_builtin_instr(&mut self, code_dir: &CodeDir, instr: &BuiltInInstruction)
{
match instr {
&BuiltInInstruction::InternalCallN => self.handle_internal_call_n(code_dir)
&BuiltInInstruction::InternalCallN => self.handle_internal_call_n(code_dir)
}
}