rishi/scryer-prolog
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introduce a better binding scheme for attributed variables

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This commit is contained in:
Mark Thom
2019-02-03 15:16:30 -07:00
parent f51405bc04
commit 3cfbbb23a3
9 changed files with 122 additions and 105 deletions
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41
src/prolog/machine/system_calls.rs
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@@ -208,24 +208,24 @@ impl MachineState {
if let Addr::Lis(l1) = ls0 {
if let Addr::Lis(l2) = self.store(self.deref(Addr::HeapCell(l1 + 1))) {
let addr = self.heap[l1 + 1].as_addr(l1 + 1);
let addr = self.heap[l1 + 1].as_addr(l1 + 1);
self.heap[l1 + 1] = HeapCellValue::Addr(Addr::HeapCell(l2 + 1));
self.trail(TrailRef::AttrVarLink(l1 + 1, addr));
}
}
}
},
&SystemClauseType::DeleteHeadAttribute => {
let addr = self.store(self.deref(self[temp_v!(1)].clone()));
match addr {
Addr::AttrVar(_, attr_var) => {
let addr = self.heap[attr_var].as_addr(attr_var).clone();
Addr::AttrVar(h) => {
let addr = self.heap[h+1].as_addr(h+1).clone();
let addr = self.store(self.deref(addr));
match addr {
Addr::Lis(l) => {
self.heap[attr_var] = HeapCellValue::Addr(Addr::HeapCell(l+1));
self.trail(TrailRef::AttrVarLink(attr_var, Addr::Lis(l)));
self.heap[h+1] = HeapCellValue::Addr(Addr::HeapCell(l+1));
self.trail(TrailRef::AttrVarLink(h+1, Addr::Lis(l)));
},
_ => {}
}
@@ -270,27 +270,16 @@ impl MachineState {
&SystemClauseType::GetAttributedVariableList => {
let attr_var = self.store(self.deref(self[temp_v!(1)].clone()));
let mut attr_var_list = match attr_var {
Addr::AttrVar(_, attr_var_list) => attr_var_list,
Addr::AttrVar(h) => h + 1,
attr_var @ Addr::HeapCell(_) | attr_var @ Addr::StackCell(..) => {
// create an AttrVar in the heap.
let h = self.heap.h;
self.heap.push(HeapCellValue::Addr(Addr::AttrVar(h, h + 2)));
self.heap.push(HeapCellValue::Addr(Addr::AttrVar(h)));
self.heap.push(HeapCellValue::Addr(Addr::HeapCell(h + 1)));
self.heap.push(HeapCellValue::Addr(Addr::HeapCell(h + 2)));
match attr_var.as_var().unwrap() {
Ref::HeapCell(r) => {
self.heap[r] = HeapCellValue::Addr(Addr::HeapCell(h));
self.trail(TrailRef::HeapCell(r));
},
Ref::StackCell(fr, sc) => {
self.and_stack[fr][sc] = Addr::HeapCell(h);
self.trail(TrailRef::StackCell(fr, sc));
}
}
h + 2
self.bind(Ref::AttrVar(h), attr_var);
h + 1
},
_ => {
self.fail = true;
@@ -298,8 +287,8 @@ impl MachineState {
}
};
let list_var = self[temp_v!(2)].clone();
self.unify(Addr::HeapCell(attr_var_list), list_var);
let list_addr = self[temp_v!(2)].clone();
self.unify(Addr::HeapCell(attr_var_list), list_addr);
},
&SystemClauseType::GetDoubleQuotes => {
let a1 = self[temp_v!(1)].clone();