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delay attributed variables goal, naively correct dif/2

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This commit is contained in:
Mark Thom
2019-04-24 20:37:31 -06:00
parent 65cc418171
commit 18a9a6434f
6 changed files with 127 additions and 38 deletions
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127
src/prolog/machine/mod.rs
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@@ -675,15 +675,10 @@ impl MachineState {
output
}
fn execute_instr(&mut self, indices: &mut IndexStore, policies: &mut MachinePolicies,
code_repo: &CodeRepo, prolog_stream: &mut PrologStream)
fn dispatch_instr(&mut self, instr: &Line, indices: &mut IndexStore, policies: &mut MachinePolicies,
prolog_stream: &mut PrologStream)
{
let instr = match code_repo.lookup_instr(self.last_call, &self.p) {
Some(instr) => instr,
None => return
};
match instr.as_ref() {
match instr {
&Line::Arithmetic(ref arith_instr) =>
self.execute_arith_instr(arith_instr),
&Line::Choice(ref choice_instr) =>
@@ -709,6 +704,17 @@ impl MachineState {
}
}
fn execute_instr(&mut self, indices: &mut IndexStore, policies: &mut MachinePolicies,
code_repo: &CodeRepo, prolog_stream: &mut PrologStream)
{
let instr = match code_repo.lookup_instr(self.last_call, &self.p) {
Some(instr) => instr,
None => return
};
self.dispatch_instr(instr.as_ref(), indices, policies, prolog_stream);
}
fn backtrack(&mut self)
{
if self.b > 0 {
@@ -727,6 +733,73 @@ impl MachineState {
}
}
fn check_machine_index(&mut self, code_repo: &CodeRepo) -> bool {
match self.p {
CodePtr::Local(LocalCodePtr::DirEntry(p))
if p < code_repo.code.len() => {},
CodePtr::Local(LocalCodePtr::UserTermExpansion(p))
if p < code_repo.term_expanders.len() => {},
CodePtr::Local(LocalCodePtr::UserTermExpansion(_)) =>
self.fail = true,
CodePtr::Local(LocalCodePtr::UserGoalExpansion(p))
if p < code_repo.goal_expanders.len() => {},
CodePtr::Local(LocalCodePtr::UserGoalExpansion(_)) =>
self.fail = true,
CodePtr::Local(LocalCodePtr::InSituDirEntry(p))
if p < code_repo.in_situ_code.len() => {},
CodePtr::Local(_) | CodePtr::REPL(..) =>
return false,
CodePtr::DynamicTransaction(..) => {
// prevent use of dynamic transactions from
// succeeding in expansions. this will be toggled
// back to true later.
self.fail = true;
return false;
},
_ => {}
}
true
}
// return true iff verify_attr_interrupt is called.
fn verify_attr_stepper(&mut self, indices: &mut IndexStore, policies: &mut MachinePolicies,
code_repo: &mut CodeRepo, prolog_stream: &mut PrologStream)
-> bool
{
loop {
let instr = match code_repo.lookup_instr(self.last_call, &self.p) {
Some(instr) => {
if instr.as_ref().is_head_instr() {
instr
} else {
let cp = self.p.local();
self.run_verify_attr_interrupt(cp);
return true;
}
},
None => return false
};
self.dispatch_instr(instr.as_ref(), indices, policies, prolog_stream);
if self.fail {
self.backtrack();
}
if !self.check_machine_index(code_repo) {
return false;
}
}
}
fn run_verify_attr_interrupt(&mut self, cp: LocalCodePtr) {
let p = self.attr_var_init.verify_attrs_loc;
self.attr_var_init.cp = cp;
self.verify_attr_interrupt(p);
}
fn query_stepper(&mut self, indices: &mut IndexStore, policies: &mut MachinePolicies,
code_repo: &mut CodeRepo, prolog_stream: &mut PrologStream)
{
@@ -738,30 +811,22 @@ impl MachineState {
}
match self.p {
CodePtr::Local(LocalCodePtr::DirEntry(p))
if p < code_repo.code.len() => {},
CodePtr::Local(LocalCodePtr::UserTermExpansion(p))
if p < code_repo.term_expanders.len() => {},
CodePtr::Local(LocalCodePtr::UserTermExpansion(_)) =>
self.fail = true,
CodePtr::Local(LocalCodePtr::UserGoalExpansion(p))
if p < code_repo.goal_expanders.len() => {},
CodePtr::Local(LocalCodePtr::UserGoalExpansion(_)) =>
self.fail = true,
CodePtr::Local(LocalCodePtr::InSituDirEntry(p))
if p < code_repo.in_situ_code.len() => {},
CodePtr::Local(_) | CodePtr::REPL(..) =>
break,
CodePtr::VerifyAttrInterrupt(p) =>
self.verify_attr_interrupt(p),
CodePtr::DynamicTransaction(..) => {
// prevent use of dynamic transactions from
// succeeding in expansions. this will be toggled
// back to true later.
self.fail = true;
break;
CodePtr::VerifyAttrInterrupt(_) => {
self.p = CodePtr::Local(self.attr_var_init.cp + 1);
if !self.verify_attr_stepper(indices, policies, code_repo, prolog_stream) {
if self.fail {
break;
}
let cp = self.p.local();
self.run_verify_attr_interrupt(cp);
}
},
_ => {}
_ =>
if !self.check_machine_index(code_repo) {
break;
}
}
}
}