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fix bug in printer over lists.

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This commit is contained in:
Mark Thom
2018-01-27 18:28:20 -07:00
parent 60440ea86b
commit 17d98f3942
4 changed files with 55 additions and 87 deletions
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46
src/prolog/heap_iter.rs
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@@ -5,26 +5,15 @@ use std::vec::Vec;
pub struct HeapCellPreOrderIterator<'a> {
machine_st : &'a MachineState,
state_stack : Vec<Ref>
state_stack : Vec<Addr>
}
impl<'a> HeapCellPreOrderIterator<'a> {
pub fn new(machine_st: &'a MachineState, r: Ref) -> Self
pub fn new(machine_st: &'a MachineState, a: Addr) -> Self
{
HeapCellPreOrderIterator {
machine_st,
state_stack: vec![r]
}
}
// called under the assumption that the location at r is about to
// be visited, and so any follow up states need to be added to
// state_stack. returns the dereferenced Addr from Ref.
fn follow(&mut self, r: Ref) -> Addr
{
match r {
Ref::HeapCell(hc) => self.follow_heap(hc),
Ref::StackCell(fr, sc) => self.follow_addr(Addr::StackCell(fr, sc))
state_stack: vec![a]
}
}
@@ -33,34 +22,35 @@ impl<'a> HeapCellPreOrderIterator<'a> {
match &self.machine_st.heap[h] {
&HeapCellValue::NamedStr(arity, _, _) => {
for idx in (1 .. arity + 1).rev() {
self.state_stack.push(Ref::HeapCell(h + idx));
self.state_stack.push(Addr::HeapCell(h + idx));
}
Addr::HeapCell(h)
},
&HeapCellValue::Addr(ref a) =>
self.follow_addr(a.clone())
self.follow(a.clone())
}
}
fn follow_addr(&mut self, addr: Addr) -> Addr
// called under the assumption that the location at r is about to
// be visited, and so any follow up states need to be added to
// state_stack. returns the dereferenced Addr from Ref.
fn follow(&mut self, addr: Addr) -> Addr
{
let da = self.machine_st.store(self.machine_st.deref(addr));
match &da {
&Addr::Con(_) => da,
&Addr::Lis(a) => {
self.state_stack.push(Ref::HeapCell(a + 1));
self.state_stack.push(Ref::HeapCell(a));
self.state_stack.push(Addr::HeapCell(a + 1));
self.state_stack.push(Addr::HeapCell(a));
da
},
&Addr::HeapCell(_) | &Addr::StackCell(_, _) =>
da,
&Addr::Str(s) => {
self.follow_heap(s); // record terms of structure.
Addr::HeapCell(s)
}
&Addr::Str(s) =>
self.follow_heap(s) // record terms of structure.
}
}
}
@@ -69,8 +59,8 @@ impl<'a> Iterator for HeapCellPreOrderIterator<'a> {
type Item = HeapCellValue;
fn next(&mut self) -> Option<Self::Item> {
if let Some(r) = self.state_stack.pop() {
match self.follow(r) {
if let Some(a) = self.state_stack.pop() {
match self.follow(a) {
Addr::HeapCell(h) => Some(self.machine_st.heap[h].clone()),
Addr::StackCell(fr, sc) => {
let heap_val = HeapCellValue::Addr(self.machine_st.and_stack[fr][sc].clone());
@@ -129,7 +119,7 @@ impl<'a> Iterator for HeapCellPostOrderIterator<'a> {
}
impl MachineState {
pub fn post_order_iter<'a>(&'a self, r: Ref) -> HeapCellPostOrderIterator<'a> {
HeapCellPostOrderIterator::new(HeapCellPreOrderIterator::new(self, r))
pub fn post_order_iter<'a>(&'a self, a: Addr) -> HeapCellPostOrderIterator<'a> {
HeapCellPostOrderIterator::new(HeapCellPreOrderIterator::new(self, a))
}
}