read from machine stack in stackful pre-order iterator (#1812)

diff --git a/src/heap_iter.rs b/src/heap_iter.rs
index e957225ca0a82e3e2ecb140b78f5176963c9e3f8..96aef41d496d357f9d8e19b6fec9b38318edeb89 100644 (file)
--- a/src/heap_iter.rs
+++ b/src/heap_iter.rs
@@ -19,28 +19,45 @@ enum IterStackLocTag {
     PendingMark,
 }
 
+#[derive(BitfieldSpecifier, Clone, Copy, Debug, PartialEq, Eq)]
+#[bits = 1]
+pub enum HeapOrStackTag {
+    Heap,
+    Stack,
+}
+
 #[bitfield]
 #[repr(u64)]
 #[derive(Clone, Copy, Debug)]
 pub struct IterStackLoc {
-    value: B62,
+    pub value: B61,
     tag: IterStackLocTag,
+    heap_or_stack: HeapOrStackTag,
 }
 
 impl IterStackLoc {
     #[inline]
-    pub fn iterable_heap_loc(h: usize) -> Self {
-        IterStackLoc::new().with_tag(IterStackLocTag::Iterable).with_value(h as u64)
+    pub fn iterable_loc(h: usize, heap_or_stack: HeapOrStackTag) -> Self {
+        IterStackLoc::new()
+            .with_tag(IterStackLocTag::Iterable)
+            .with_heap_or_stack(heap_or_stack)
+            .with_value(h as u64)
     }
 
     #[inline]
-    pub fn mark_heap_loc(h: usize) -> Self {
-        IterStackLoc::new().with_tag(IterStackLocTag::Marked).with_value(h as u64)
+    fn mark_loc(h: usize, heap_or_stack: HeapOrStackTag) -> Self {
+        IterStackLoc::new()
+            .with_tag(IterStackLocTag::Marked)
+            .with_heap_or_stack(heap_or_stack)
+            .with_value(h as u64)
     }
 
     #[inline]
-    pub fn pending_mark_heap_loc(h: usize) -> Self {
-        IterStackLoc::new().with_tag(IterStackLocTag::PendingMark).with_value(h as u64)
+    fn pending_mark_loc(h: usize, heap_or_stack: HeapOrStackTag) -> Self {
+        IterStackLoc::new()
+            .with_tag(IterStackLocTag::PendingMark)
+            .with_heap_or_stack(heap_or_stack)
+            .with_value(h as u64)
     }
 
     #[inline]
@@ -52,39 +69,35 @@ impl IterStackLoc {
     pub fn is_pending_mark(self) -> bool {
         self.tag() == IterStackLocTag::PendingMark
     }
-}
 
-#[inline]
-fn forward_if_referent_marked(heap: &mut [HeapCellValue], h: usize) {
-    read_heap_cell!(heap[h],
-        (HeapCellValueTag::Str
-         | HeapCellValueTag::Lis
-         | HeapCellValueTag::AttrVar
-         | HeapCellValueTag::Var
-         | HeapCellValueTag::PStrLoc, vh) => {
-            if heap[vh].get_mark_bit() {
-                heap[h].set_forwarding_bit(true);
+    #[inline]
+    pub fn as_ref(self) -> Ref {
+        match self.heap_or_stack() {
+            HeapOrStackTag::Heap => {
+                Ref::heap_cell(self.value() as usize)
+            }
+            HeapOrStackTag::Stack => {
+                Ref::stack_cell(self.value() as usize)
             }
         }
-        _ => {}
-    )
+    }
 }
 
 #[derive(Debug)]
 pub struct StackfulPreOrderHeapIter<'a> {
     pub heap: &'a mut Vec<HeapCellValue>,
-    machine_stack: Option<&'a Stack>,
+    pub machine_stack: &'a mut Stack,
     stack: Vec<IterStackLoc>,
-    h: usize,
+    h: IterStackLoc,
 }
 
 impl<'a> Drop for StackfulPreOrderHeapIter<'a> {
     fn drop(&mut self) {
         while let Some(h) = self.stack.pop() {
-            let h = h.value() as usize;
+            let cell = self.read_cell_mut(h);
 
-            self.heap[h].set_forwarding_bit(false);
-            self.heap[h].set_mark_bit(false);
+            cell.set_forwarding_bit(false);
+            cell.set_mark_bit(false);
         }
 
         self.heap.pop();
@@ -92,53 +105,93 @@ impl<'a> Drop for StackfulPreOrderHeapIter<'a> {
 }
 
 pub trait FocusedHeapIter: Iterator<Item = HeapCellValue> {
-    fn focus(&self) -> usize;
+    fn focus(&self) -> IterStackLoc;
 }
 
 impl<'a> FocusedHeapIter for StackfulPreOrderHeapIter<'a> {
     #[inline]
-    fn focus(&self) -> usize {
+    fn focus(&self) -> IterStackLoc {
         self.h
     }
 }
 
 impl<'a> StackfulPreOrderHeapIter<'a> {
     #[inline]
-    fn new(heap: &'a mut Vec<HeapCellValue>, cell: HeapCellValue) -> Self {
-        let h = heap.len();
+    fn new(heap: &'a mut Vec<HeapCellValue>, stack: &'a mut Stack, cell: HeapCellValue) -> Self {
+        let h = IterStackLoc::iterable_loc(heap.len(), HeapOrStackTag::Heap);
         heap.push(cell);
 
         Self {
             heap,
             h,
-            machine_stack: None,
-            stack: vec![IterStackLoc::iterable_heap_loc(h)],
+            machine_stack: stack,
+            stack: vec![h],
         }
     }
 
-    pub fn iterate_over_machine_stack(&mut self, stack: &'a Stack) {
-        self.machine_stack = Some(stack);
+    #[inline]
+    fn forward_if_referent_marked(&mut self, loc: IterStackLoc) {
+        read_heap_cell!(self.read_cell(loc),
+            (HeapCellValueTag::Str |
+             HeapCellValueTag::Lis |
+             HeapCellValueTag::AttrVar |
+             HeapCellValueTag::Var |
+             HeapCellValueTag::PStrLoc, vh) => {
+                if self.heap[vh].get_mark_bit() {
+                    self.read_cell_mut(loc).set_forwarding_bit(true);
+                }
+            }
+            (HeapCellValueTag::StackVar, vs) => {
+                if self.machine_stack[vs].get_mark_bit() {
+                    self.read_cell_mut(loc).set_forwarding_bit(true);
+                }
+            }
+            _ => {}
+        );
+    }
+
+    #[inline]
+    pub fn push_stack(&mut self, h: IterStackLoc) {
+        self.stack.push(h);
     }
 
     #[inline]
-    pub fn push_stack(&mut self, h: usize) {
-        self.stack.push(IterStackLoc::iterable_heap_loc(h));
+    pub fn read_cell_mut(&mut self, loc: IterStackLoc) -> &mut HeapCellValue {
+        match loc.heap_or_stack() {
+            HeapOrStackTag::Heap => {
+                &mut self.heap[loc.value() as usize]
+            }
+            HeapOrStackTag::Stack => {
+                &mut self.machine_stack[loc.value() as usize]
+            }
+        }
     }
 
     #[inline]
-    pub fn stack_last(&self) -> Option<usize> {
+    pub fn read_cell(&self, loc: IterStackLoc) -> HeapCellValue {
+        match loc.heap_or_stack() {
+            HeapOrStackTag::Heap => {
+                self.heap[loc.value() as usize]
+            }
+            HeapOrStackTag::Stack => {
+                self.machine_stack[loc.value() as usize]
+            }
+        }
+    }
+
+    #[inline]
+    pub fn stack_last(&self) -> Option<IterStackLoc> {
         for h in self.stack.iter().rev() {
             let is_readable_marked = h.is_marked();
-            let h = h.value() as usize;
-            let cell = self.heap[h];
+            let cell = self.read_cell(*h);
 
             if cell.get_forwarding_bit() {
-                return Some(h);
+                return Some(*h);
             } else if cell.get_mark_bit() && !is_readable_marked {
                 continue;
             }
 
-            return Some(h);
+            return Some(*h);
         }
 
         None
@@ -148,10 +201,9 @@ impl<'a> StackfulPreOrderHeapIter<'a> {
     pub fn pop_stack(&mut self) -> Option<HeapCellValue> {
         while let Some(h) = self.stack.pop() {
             let is_readable_marked = h.is_marked();
-            let h = h.value() as usize;
-            self.h = h;
 
-            let cell = &mut self.heap[h];
+            self.h = h;
+            let cell = self.read_cell_mut(h);
 
             if cell.get_forwarding_bit() {
                 cell.set_forwarding_bit(false);
@@ -166,50 +218,29 @@ impl<'a> StackfulPreOrderHeapIter<'a> {
         None
     }
 
-    fn push_if_unmarked(&mut self, h: usize) {
-        if !self.heap[h].get_mark_bit() {
-            self.heap[h].set_mark_bit(true);
-            self.stack.push(IterStackLoc::iterable_heap_loc(h));
-        }
-    }
-
-    fn stack_deref(&self, s: usize) -> Option<HeapCellValue> {
-        if let Some(stack) = &self.machine_stack {
-            let mut cell = stack[s];
+    fn push_if_unmarked(&mut self, loc: IterStackLoc) {
+        let cell = self.read_cell_mut(loc);
 
-            while cell.is_stack_var() {
-                let s = cell.get_value();
-
-                if cell == stack[s] {
-                    break;
-                }
-
-                cell = stack[s];
-            }
-
-            return Some(cell);
+        if !cell.get_mark_bit() {
+            cell.set_mark_bit(true);
+            self.stack.push(IterStackLoc::iterable_loc(loc.value() as usize, loc.heap_or_stack()));
         }
-
-        None
     }
 
     fn follow(&mut self) -> Option<HeapCellValue> {
         while let Some(h) = self.stack.pop() {
             if h.is_pending_mark() {
-                let h = h.value() as usize;
-
                 self.push_if_unmarked(h);
-                self.stack.push(IterStackLoc::mark_heap_loc(h));
+                self.stack.push(IterStackLoc::mark_loc(h.value() as usize, h.heap_or_stack()));
 
-                forward_if_referent_marked(&mut self.heap, h);
+                self.forward_if_referent_marked(h);
                 continue;
             }
 
-            let is_readable_marked = h.is_marked();
-            let h = h.value() as usize;
-
             self.h = h;
-            let cell = &mut self.heap[h];
+
+            let is_readable_marked = h.is_marked();
+            let cell = self.read_cell_mut(h);
 
             if cell.get_forwarding_bit() {
                 let copy = *cell;
@@ -220,62 +251,73 @@ impl<'a> StackfulPreOrderHeapIter<'a> {
                 continue;
             }
 
-            let cell = if cell.get_tag() == HeapCellValueTag::StackVar {
-                let cell = *cell;
-                self.stack_deref(cell.get_value()).unwrap_or(cell)
-            } else {
-                *cell
-            };
-
-            read_heap_cell!(cell,
+            read_heap_cell!(*cell,
                (HeapCellValueTag::Str | HeapCellValueTag::PStrLoc, vh) => {
-                   self.push_if_unmarked(vh);
-                   self.stack.push(IterStackLoc::mark_heap_loc(vh));
+                   let loc = IterStackLoc::iterable_loc(vh, HeapOrStackTag::Heap);
+
+                   self.push_if_unmarked(loc);
+                   self.stack.push(IterStackLoc::mark_loc(vh, HeapOrStackTag::Heap));
                }
                (HeapCellValueTag::Lis, vh) => {
-                   self.push_if_unmarked(vh);
+                   let loc = IterStackLoc::iterable_loc(vh, HeapOrStackTag::Heap);
+
+                   self.push_if_unmarked(loc);
 
-                   self.stack.push(IterStackLoc::pending_mark_heap_loc(vh + 1));
-                   self.stack.push(IterStackLoc::mark_heap_loc(vh));
+                   self.stack.push(IterStackLoc::pending_mark_loc(vh + 1, HeapOrStackTag::Heap));
+                   self.stack.push(IterStackLoc::mark_loc(vh, HeapOrStackTag::Heap));
 
-                   forward_if_referent_marked(&mut self.heap, vh);
+                   self.forward_if_referent_marked(loc);
 
-                   return Some(self.heap[h]);
+                   return Some(self.read_cell(h));
                }
                (HeapCellValueTag::AttrVar | HeapCellValueTag::Var, vh) => {
-                   self.push_if_unmarked(vh);
-                   self.stack.push(IterStackLoc::mark_heap_loc(vh));
-                   forward_if_referent_marked(&mut self.heap, vh);
+                   let loc = IterStackLoc::iterable_loc(vh, HeapOrStackTag::Heap);
+
+                   self.push_if_unmarked(loc);
+                   self.stack.push(IterStackLoc::mark_loc(vh, HeapOrStackTag::Heap));
+                   self.forward_if_referent_marked(loc);
+               }
+               (HeapCellValueTag::StackVar, vs) => {
+                   let loc = IterStackLoc::iterable_loc(vs, HeapOrStackTag::Stack);
+
+                   self.push_if_unmarked(loc);
+                   self.stack.push(IterStackLoc::mark_loc(vs, HeapOrStackTag::Stack));
+                   self.forward_if_referent_marked(loc);
                }
                (HeapCellValueTag::PStrOffset, offset) => {
-                   self.push_if_unmarked(offset);
-                   self.stack.push(IterStackLoc::iterable_heap_loc(h+1));
+                   self.push_if_unmarked(IterStackLoc::iterable_loc(offset, HeapOrStackTag::Heap));
+                   self.stack.push(IterStackLoc::iterable_loc((h.value()+1) as usize, HeapOrStackTag::Heap));
 
-                   return Some(self.heap[h]);
+                   return Some(self.read_cell(h));
                }
                (HeapCellValueTag::PStr) => {
-                   self.push_if_unmarked(h);
+                   let tail_loc = IterStackLoc::iterable_loc((h.value()+1) as usize, HeapOrStackTag::Heap);
 
-                   self.stack.push(IterStackLoc::iterable_heap_loc(h+1));
-                   forward_if_referent_marked(&mut self.heap, h+1);
+                   self.push_if_unmarked(IterStackLoc::iterable_loc(h.value() as usize, HeapOrStackTag::Heap));
+                   self.stack.push(tail_loc);
+                   self.forward_if_referent_marked(tail_loc);
 
-                   return Some(self.heap[h]);
+                   return Some(self.read_cell(h));
                }
                (HeapCellValueTag::Atom, (_name, arity)) => {
-                   for h in (h + 2 .. h + arity + 1).rev() {
-                       self.stack.push(IterStackLoc::pending_mark_heap_loc(h));
+                   let l = h.value() as usize;
+
+                   for l in (l + 2 .. l + arity + 1).rev() {
+                       self.stack.push(IterStackLoc::pending_mark_loc(l, HeapOrStackTag::Heap));
                    }
 
                    if arity > 0 {
-                       self.push_if_unmarked(h+1);
-                       self.stack.push(IterStackLoc::mark_heap_loc(h+1));
-                       forward_if_referent_marked(&mut self.heap, h+1);
+                       let first_arg_loc = IterStackLoc::iterable_loc(l+1, HeapOrStackTag::Heap);
+
+                       self.push_if_unmarked(first_arg_loc);
+                       self.stack.push(IterStackLoc::mark_loc(l+1, HeapOrStackTag::Heap));
+                       self.forward_if_referent_marked(first_arg_loc);
                    }
 
-                   return Some(self.heap[h]);
+                   return Some(self.read_cell(h));
                }
                _ => {
-                   return Some(cell);
+                   return Some(*cell);
                }
             )
         }
@@ -303,19 +345,20 @@ pub(crate) fn stackless_preorder_iter(
 }
 
 #[inline(always)]
-pub(crate) fn stackful_preorder_iter(
-    heap: &mut Vec<HeapCellValue>,
+pub(crate) fn stackful_preorder_iter<'a>(
+    heap: &'a mut Vec<HeapCellValue>,
+    stack: &'a mut Stack,
     cell: HeapCellValue,
-) -> StackfulPreOrderHeapIter {
-    StackfulPreOrderHeapIter::new(heap, cell)
+) -> StackfulPreOrderHeapIter<'a> {
+    StackfulPreOrderHeapIter::new(heap, stack, cell)
 }
 
 #[derive(Debug)]
 pub(crate) struct PostOrderIterator<Iter: FocusedHeapIter> {
-    focus: usize,
+    focus: IterStackLoc,
     base_iter: Iter,
     base_iter_valid: bool,
-    parent_stack: Vec<(usize, HeapCellValue, usize)>, // number of children, parent node, focus.
+    parent_stack: Vec<(usize, HeapCellValue, IterStackLoc)>, // number of children, parent node, focus.
 }
 
 impl<Iter: FocusedHeapIter> Deref for PostOrderIterator<Iter> {
@@ -329,7 +372,7 @@ impl<Iter: FocusedHeapIter> Deref for PostOrderIterator<Iter> {
 impl<Iter: FocusedHeapIter> PostOrderIterator<Iter> {
     pub(crate) fn new(base_iter: Iter) -> Self {
         PostOrderIterator {
-            focus: 0,
+            focus: IterStackLoc::iterable_loc(0, HeapOrStackTag::Heap),
             base_iter,
             base_iter_valid: true,
             parent_stack: vec![],
@@ -386,7 +429,7 @@ impl<Iter: FocusedHeapIter> Iterator for PostOrderIterator<Iter> {
 
 impl<Iter: FocusedHeapIter> FocusedHeapIter for PostOrderIterator<Iter> {
     #[inline(always)]
-    fn focus(&self) -> usize {
+    fn focus(&self) -> IterStackLoc {
         self.focus
     }
 }
@@ -402,7 +445,8 @@ impl<Iter: FocusedHeapIter> PostOrderIterator<Iter> {
         if let Some((_child_count, item, focus)) = self.parent_stack.last() {
             read_heap_cell!(item,
                 (HeapCellValueTag::Atom, (_name, arity)) => {
-                    return focus + arity >= idx_loc && *focus < idx_loc;
+                    let focus = focus.value() as usize;
+                    return focus + arity >= idx_loc && focus < idx_loc;
                 }
                 _ => {}
             );
@@ -435,9 +479,10 @@ impl<'a> LeftistPostOrderHeapIter<'a> {
 #[inline]
 pub(crate) fn stackful_post_order_iter<'a>(
     heap: &'a mut Heap,
+    stack: &'a mut Stack,
     cell: HeapCellValue,
 ) -> LeftistPostOrderHeapIter<'a> {
-    PostOrderIterator::new(StackfulPreOrderHeapIter::new(heap, cell))
+    PostOrderIterator::new(StackfulPreOrderHeapIter::new(heap, stack, cell))
 }
 
 #[cfg(test)]
@@ -1416,7 +1461,11 @@ mod tests {
             .extend(functor!(f_atom, [atom(a_atom), atom(b_atom)]));
 
         {
-            let mut iter = StackfulPreOrderHeapIter::new(&mut wam.machine_st.heap, str_loc_as_cell!(0));
+            let mut iter = StackfulPreOrderHeapIter::new(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                str_loc_as_cell!(0),
+            );
 
             assert_eq!(
                 unmark_cell_bits!(iter.next().unwrap()),
@@ -1447,7 +1496,11 @@ mod tests {
         ));
 
         for _ in 0..20 {
-            let mut iter = StackfulPreOrderHeapIter::new(&mut wam.machine_st.heap, str_loc_as_cell!(0));
+            let mut iter = StackfulPreOrderHeapIter::new(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                str_loc_as_cell!(0),
+            );
 
             assert_eq!(
                 unmark_cell_bits!(iter.next().unwrap()),
@@ -1475,7 +1528,12 @@ mod tests {
         {
             wam.machine_st.heap.push(heap_loc_as_cell!(0));
 
-            let mut iter = StackfulPreOrderHeapIter::new(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = StackfulPreOrderHeapIter::new(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                heap_loc_as_cell!(0),
+            );
+
             let mut var = heap_loc_as_cell!(0);
 
             // self-referencing variables are copied with their forwarding
@@ -1497,7 +1555,11 @@ mod tests {
             wam.machine_st.heap.push(heap_loc_as_cell!(1));
             wam.machine_st.heap.push(heap_loc_as_cell!(0));
 
-            let mut iter = StackfulPreOrderHeapIter::new(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = StackfulPreOrderHeapIter::new(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                heap_loc_as_cell!(0),
+            );
 
             assert_eq!(
                 unmark_cell_bits!(iter.next().unwrap()),
@@ -1517,7 +1579,11 @@ mod tests {
         wam.machine_st.heap.push(empty_list_as_cell!());
 
         {
-            let mut iter = StackfulPreOrderHeapIter::new(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = StackfulPreOrderHeapIter::new(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                heap_loc_as_cell!(0),
+            );
 
             assert_eq!(
                 unmark_cell_bits!(iter.next().unwrap()),
@@ -1549,7 +1615,11 @@ mod tests {
         wam.machine_st.heap.push(heap_loc_as_cell!(0));
 
         {
-            let mut iter = StackfulPreOrderHeapIter::new(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = StackfulPreOrderHeapIter::new(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                heap_loc_as_cell!(0),
+            );
 
             // the cycle will be iterated twice before being detected.
             assert_eq!(
@@ -1577,7 +1647,11 @@ mod tests {
         }
 
         {
-            let mut iter = StackfulPreOrderHeapIter::new(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = StackfulPreOrderHeapIter::new(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                heap_loc_as_cell!(0),
+            );
 
             // cut the iteration short to check that all cells are
             // unmarked and unforwarded by the Drop instance of
@@ -1611,7 +1685,11 @@ mod tests {
         let pstr_cell = wam.machine_st.heap[pstr_var_cell.get_value() as usize];
 
         {
-            let mut iter = StackfulPreOrderHeapIter::new(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = StackfulPreOrderHeapIter::new(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                heap_loc_as_cell!(0),
+            );
 
             assert_eq!(unmark_cell_bits!(iter.next().unwrap()), pstr_cell);
             assert_eq!(
@@ -1631,7 +1709,11 @@ mod tests {
         let pstr_second_cell = wam.machine_st.heap[pstr_second_var_cell.get_value() as usize];
 
         {
-            let mut iter = stackful_preorder_iter(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = stackful_preorder_iter(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                heap_loc_as_cell!(0),
+            );
 
             assert_eq!(unmark_cell_bits!(iter.next().unwrap()), pstr_cell);
             assert_eq!(unmark_cell_bits!(iter.next().unwrap()), pstr_second_cell);
@@ -1650,7 +1732,12 @@ mod tests {
         wam.machine_st.heap.push(fixnum_as_cell!(Fixnum::build_with(0i64)));
 
         {
-            let mut iter = stackful_preorder_iter(&mut wam.machine_st.heap, pstr_loc_as_cell!(0));
+            let mut iter = stackful_preorder_iter(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                pstr_loc_as_cell!(0),
+            );
+
             let pstr_offset_cell = pstr_offset_as_cell!(0);
 
             // pstr_offset_cell.set_forwarding_bit(true);
@@ -1675,7 +1762,12 @@ mod tests {
         wam.machine_st.heap.push(fixnum_as_cell!(Fixnum::build_with(1i64)));
 
         {
-            let mut iter = stackful_preorder_iter(&mut wam.machine_st.heap, pstr_loc_as_cell!(0));
+            let mut iter = stackful_preorder_iter(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                pstr_loc_as_cell!(0),
+            );
+
             let pstr_offset_cell = pstr_offset_as_cell!(0);
 
             // pstr_offset_cell.set_forwarding_bit(true);
@@ -1688,7 +1780,7 @@ mod tests {
 
             let h = iter.focus();
 
-            assert_eq!(h, 5);
+            assert_eq!(h.value(), 5);
             assert_eq!(unmark_cell_bits!(iter.heap[4]), pstr_offset_as_cell!(0));
             assert_eq!(unmark_cell_bits!(iter.heap[5]), fixnum_as_cell!(Fixnum::build_with(1i64)));
 
@@ -1708,7 +1800,11 @@ mod tests {
         wam.machine_st.heap.extend(functor);
 
         {
-            let mut iter = StackfulPreOrderHeapIter::new(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = StackfulPreOrderHeapIter::new(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                heap_loc_as_cell!(0),
+            );
 
             assert_eq!(
                 unmark_cell_bits!(iter.next().unwrap()),
@@ -1767,7 +1863,11 @@ mod tests {
         wam.machine_st.heap[4] = list_loc_as_cell!(1);
 
         {
-            let mut iter = stackful_preorder_iter(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = stackful_preorder_iter(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                heap_loc_as_cell!(0),
+            );
 
             assert_eq!(
                 unmark_cell_bits!(iter.next().unwrap()),
@@ -1834,6 +1934,7 @@ mod tests {
         {
             let mut iter = StackfulPreOrderHeapIter::new(
                 &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
                 heap_loc_as_cell!(0),
             );
 
@@ -1865,6 +1966,7 @@ mod tests {
         {
             let mut iter = stackful_preorder_iter(
                 &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
                 heap_loc_as_cell!(0),
             );
 
@@ -1899,6 +2001,7 @@ mod tests {
         {
             let mut iter = stackful_preorder_iter(
                 &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
                 heap_loc_as_cell!(0),
             );
 
@@ -1933,7 +2036,11 @@ mod tests {
             .extend(functor!(f_atom, [atom(a_atom), atom(b_atom)]));
 
         {
-            let mut iter = stackful_post_order_iter(&mut wam.machine_st.heap, str_loc_as_cell!(0));
+            let mut iter = stackful_post_order_iter(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                str_loc_as_cell!(0),
+            );
 
             assert_eq!(
                 unmark_cell_bits!(iter.next().unwrap()),
@@ -1964,7 +2071,11 @@ mod tests {
         ));
 
         for _ in 0..20 { // 0000 {
-            let mut iter = stackful_post_order_iter(&mut wam.machine_st.heap, str_loc_as_cell!(0));
+            let mut iter = stackful_post_order_iter(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                str_loc_as_cell!(0),
+            );
 
             assert_eq!(
                 unmark_cell_bits!(iter.next().unwrap()),
@@ -1994,7 +2105,12 @@ mod tests {
         {
             wam.machine_st.heap.push(heap_loc_as_cell!(0));
 
-            let mut iter = stackful_post_order_iter(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = stackful_post_order_iter(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                heap_loc_as_cell!(0),
+            );
+
             let mut var = heap_loc_as_cell!(0);
 
             // self-referencing variables are copied with their forwarding
@@ -2016,7 +2132,11 @@ mod tests {
             wam.machine_st.heap.push(heap_loc_as_cell!(1));
             wam.machine_st.heap.push(heap_loc_as_cell!(0));
 
-            let mut iter = stackful_post_order_iter(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = stackful_post_order_iter(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                heap_loc_as_cell!(0),
+            );
 
             assert_eq!(
                 unmark_cell_bits!(iter.next().unwrap()),
@@ -2036,7 +2156,11 @@ mod tests {
         wam.machine_st.heap.push(empty_list_as_cell!());
 
         {
-            let mut iter = stackful_post_order_iter(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = stackful_post_order_iter(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                heap_loc_as_cell!(0),
+            );
 
             assert_eq!(
                 unmark_cell_bits!(iter.next().unwrap()),
@@ -2068,7 +2192,11 @@ mod tests {
         wam.machine_st.heap.push(heap_loc_as_cell!(0));
 
         {
-            let mut iter = stackful_post_order_iter(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = stackful_post_order_iter(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                heap_loc_as_cell!(0),
+            );
 
             // the cycle will be iterated twice before being detected.
             assert_eq!(
@@ -2098,6 +2226,7 @@ mod tests {
         {
             let mut iter = stackful_post_order_iter(
                 &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
                 heap_loc_as_cell!(0),
             );
 
@@ -2133,7 +2262,11 @@ mod tests {
         let pstr_cell = wam.machine_st.heap[pstr_var_cell.get_value() as usize];
 
         {
-            let mut iter = stackful_post_order_iter(&mut wam.machine_st.heap, pstr_loc_as_cell!(0));
+            let mut iter = stackful_post_order_iter(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                pstr_loc_as_cell!(0),
+            );
 
             assert_eq!(
                 unmark_cell_bits!(iter.next().unwrap()),
@@ -2152,7 +2285,11 @@ mod tests {
         let pstr_second_cell = wam.machine_st.heap[pstr_second_var_cell.get_value() as usize];
 
         {
-            let mut iter = stackful_post_order_iter(&mut wam.machine_st.heap, pstr_loc_as_cell!(0));
+            let mut iter = stackful_post_order_iter(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                pstr_loc_as_cell!(0),
+            );
 
             assert_eq!(
                 unmark_cell_bits!(iter.next().unwrap()),
@@ -2171,7 +2308,11 @@ mod tests {
         wam.machine_st.heap.push(fixnum_as_cell!(Fixnum::build_with(0i64)));
 
         {
-            let mut iter = stackful_post_order_iter(&mut wam.machine_st.heap, pstr_loc_as_cell!(0));
+            let mut iter = stackful_post_order_iter(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                pstr_loc_as_cell!(0),
+            );
 
             assert_eq!(iter.next().unwrap(), fixnum_as_cell!(Fixnum::build_with(0i64)));
             assert_eq!(unmark_cell_bits!(iter.next().unwrap()), pstr_offset_as_cell!(0));
@@ -2186,7 +2327,11 @@ mod tests {
         wam.machine_st.heap.push(fixnum_as_cell!(Fixnum::build_with(1i64)));
 
         {
-            let mut iter = stackful_post_order_iter(&mut wam.machine_st.heap, pstr_loc_as_cell!(0));
+            let mut iter = stackful_post_order_iter(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                pstr_loc_as_cell!(0),
+            );
 
             assert_eq!(iter.next().unwrap(), fixnum_as_cell!(Fixnum::build_with(1i64)));
             assert_eq!(unmark_cell_bits!(iter.next().unwrap()), pstr_offset_as_cell!(0));
@@ -2210,7 +2355,11 @@ mod tests {
         wam.machine_st.heap.extend(functor);
 
         {
-            let mut iter = stackful_post_order_iter(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = stackful_post_order_iter(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                heap_loc_as_cell!(0),
+            );
 
             assert_eq!(
                 unmark_cell_bits!(iter.next().unwrap()),
@@ -2270,7 +2419,11 @@ mod tests {
         wam.machine_st.heap[4] = list_loc_as_cell!(1);
 
         {
-            let mut iter = stackful_post_order_iter(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = stackful_post_order_iter(
+                &mut wam.machine_st.heap,
+                &mut wam.machine_st.stack,
+                heap_loc_as_cell!(0),
+            );
 
             assert_eq!(
                 unmark_cell_bits!(iter.next().unwrap()),
@@ -2377,7 +2530,10 @@ mod tests {
         ));
 
         for _ in 0..20 {
-            let mut iter = stackless_post_order_iter(&mut wam.machine_st.heap, str_loc_as_cell!(0));
+            let mut iter = stackless_post_order_iter(
+                &mut wam.machine_st.heap,
+                str_loc_as_cell!(0),
+            );
 
             assert_eq!(unmark_cell_bits!(iter.next().unwrap()), str_loc_as_cell!(0));
 
@@ -2407,7 +2563,10 @@ mod tests {
         {
             wam.machine_st.heap.push(heap_loc_as_cell!(0));
 
-            let mut iter = stackless_post_order_iter(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = stackless_post_order_iter(
+                &mut wam.machine_st.heap,
+                heap_loc_as_cell!(0),
+            );
 
             assert_eq!(
                 unmark_cell_bits!(iter.next().unwrap()),
@@ -2423,7 +2582,10 @@ mod tests {
             wam.machine_st.heap.push(heap_loc_as_cell!(1));
             wam.machine_st.heap.push(heap_loc_as_cell!(0));
 
-            let mut iter = stackless_post_order_iter(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
+            let mut iter = stackless_post_order_iter(
+                &mut wam.machine_st.heap,
+                heap_loc_as_cell!(0),
+            );
 
             assert_eq!(
                 unmark_cell_bits!(iter.next().unwrap()),

diff --git a/src/heap_print.rs b/src/heap_print.rs
index c0ea5fa3abcec79f45ae965ded33615f44209327..910600ab0ea60418ac60ce8a718e9f788e305e95 100644 (file)
--- a/src/heap_print.rs
+++ b/src/heap_print.rs
@@ -116,7 +116,9 @@ impl<'a> StackfulPreOrderHeapIter<'a> {
         let mut parent_spec = DirectedOp::Left(atom!("-"), OpDesc::build_with(200, FY as u8));
 
         loop {
-            read_heap_cell!(self.heap[h],
+            let cell = self.read_cell(h);
+
+            read_heap_cell!(cell,
                 (HeapCellValueTag::Str, s) => {
                     read_heap_cell!(self.heap[s],
                         (HeapCellValueTag::Atom, (name, _arity)) => {
@@ -125,7 +127,7 @@ impl<'a> StackfulPreOrderHeapIter<'a> {
                                     if needs_bracketing(spec, &parent_spec) {
                                         return false;
                                     } else {
-                                        h = s + 1;
+                                        h = IterStackLoc::iterable_loc(s + 1, HeapOrStackTag::Heap);
                                         parent_spec = DirectedOp::Right(name, spec);
                                         continue;
                                     }
@@ -140,7 +142,7 @@ impl<'a> StackfulPreOrderHeapIter<'a> {
                     )
                 }
                 _ => {
-                    return property_check(self.heap[h]);
+                    return property_check(cell);
                 }
             )
         }
@@ -150,12 +152,12 @@ impl<'a> StackfulPreOrderHeapIter<'a> {
     where
         P: Fn(HeapCellValue) -> bool,
     {
-        let addr = match self.stack_last() {
-            Some(h) => self.heap[h],
+        let cell = match self.stack_last() {
+            Some(h) => self.read_cell(h),
             None => return false,
         };
 
-        property_check(addr)
+        property_check(cell)
     }
 }
 
@@ -475,7 +477,6 @@ pub struct HCPrinter<'a, Outputter> {
     outputter: Outputter,
     iter: StackfulPreOrderHeapIter<'a>,
     atom_tbl: &'a mut AtomTable,
-    stack: &'a Stack,
     op_dir: &'a OpDir,
     state_stack: Vec<TokenOrRedirect>,
     toplevel_spec: Option<DirectedOp>,
@@ -541,16 +542,15 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
     pub fn new(
         heap: &'a mut Heap,
         atom_tbl: &'a mut AtomTable,
-        stack: &'a Stack,
+        stack: &'a mut Stack,
         op_dir: &'a OpDir,
         output: Outputter,
         cell: HeapCellValue,
     ) -> Self {
         HCPrinter {
             outputter: output,
-            iter: stackful_preorder_iter(heap, cell),
+            iter: stackful_preorder_iter(heap, stack, cell),
             atom_tbl,
-            stack,
             op_dir,
             state_stack: vec![],
             toplevel_spec: None,
@@ -758,14 +758,14 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
     fn format_numbered_vars(&mut self) -> bool {
         let h = self.iter.stack_last().unwrap();
 
-        let addr = self.iter.heap[h];
-        let addr = heap_bound_store(
+        let cell = self.iter.read_cell(h);
+        let cell = heap_bound_store(
             &self.iter.heap,
-            heap_bound_deref(&self.iter.heap, addr),
+            heap_bound_deref(&self.iter.heap, cell),
         );
 
         // 7.10.4
-        if let Some(var) = numbervar(&self.numbervars_offset, addr) {
+        if let Some(var) = numbervar(&self.numbervars_offset, cell) {
             self.iter.pop_stack();
             self.state_stack.push(TokenOrRedirect::NumberedVar(var));
             return true;
@@ -809,11 +809,11 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
         };
     }
 
-    fn offset_as_string(&mut self, h: usize) -> Option<String> {
-        let addr = self.iter.heap[h];
+    fn offset_as_string(&mut self, h: IterStackLoc) -> Option<String> {
+        let cell = self.iter.read_cell(h);
 
-        if let Some(var) = self.var_names.get(&addr) {
-            read_heap_cell!(addr,
+        if let Some(var) = self.var_names.get(&cell) {
+            read_heap_cell!(cell,
                (HeapCellValueTag::Var | HeapCellValueTag::AttrVar | HeapCellValueTag::StackVar) => {
                    return Some(format!("{}", var.as_str()));
                }
@@ -824,7 +824,7 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
             );
         }
 
-        read_heap_cell!(addr,
+        read_heap_cell!(cell,
             (HeapCellValueTag::Lis | HeapCellValueTag::Str, h) => {
                 Some(format!("{}", h))
             }
@@ -1167,7 +1167,7 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
 
     fn print_list_like(&mut self, mut max_depth: usize) {
         let focus = self.iter.focus();
-        let mut heap_pstr_iter = HeapPStrIter::new(self.iter.heap, focus);
+        let mut heap_pstr_iter = HeapPStrIter::new(self.iter.heap, focus.value() as usize);
 
         if heap_pstr_iter.next().is_some() {
             while let Some(_) = heap_pstr_iter.next() {}
@@ -1179,7 +1179,7 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
         let end_cell = heap_pstr_iter.focus;
 
         if self.check_max_depth(&mut max_depth) {
-            self.remove_list_children(focus);
+            self.remove_list_children(focus.value() as usize);
             self.state_stack.push(TokenOrRedirect::Atom(atom!("...")));
             return;
         }
@@ -1187,26 +1187,26 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
         let at_cdr = self.outputter.ends_with("|");
 
         if !at_cdr && !self.ignore_ops && end_cell.is_string_terminator(&self.iter.heap) {
-            self.remove_list_children(focus);
-            return self.print_proper_string(focus, max_depth);
+            self.remove_list_children(focus.value() as usize);
+            return self.print_proper_string(focus.value() as usize, max_depth);
         }
 
         if self.ignore_ops {
             self.at_cdr(",");
-            self.remove_list_children(focus);
+            self.remove_list_children(focus.value() as usize);
 
-            if !self.print_string_as_functor(focus, max_depth) {
+            if !self.print_string_as_functor(focus.value() as usize, max_depth) {
                 if end_cell == empty_list_as_cell!() {
                     append_str!(self, "[]");
                 } else {
                     self.state_stack.push(TokenOrRedirect::FunctorRedirect(max_depth));
-                    self.iter.push_stack(end_h);
+                    self.iter.push_stack(IterStackLoc::iterable_loc(end_h, HeapOrStackTag::Heap));
                 }
             }
         } else {
             let value = heap_bound_store(
                 self.iter.heap,
-                heap_bound_deref(self.iter.heap, self.iter.heap[focus]),
+                heap_bound_deref(self.iter.heap, self.iter.read_cell(focus)),
             );
 
             read_heap_cell!(value,
@@ -1217,7 +1217,7 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
                     let switch = Rc::new(Cell::new((!at_cdr, 0)));
                     self.state_stack.push(TokenOrRedirect::CloseList(switch.clone()));
 
-                    let (h, offset) = pstr_loc_and_offset(self.iter.heap, focus);
+                    let (h, offset) = pstr_loc_and_offset(self.iter.heap, focus.value() as usize);
                     let pstr = cell_as_string!(self.iter.heap[h]);
 
                     let pstr = pstr.as_str_from(offset.get_num() as usize);
@@ -1239,7 +1239,7 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
                         self.state_stack.push(TokenOrRedirect::HeadTailSeparator);
                     } else if end_cell != empty_list_as_cell!() {
                         if tag == HeapCellValueTag::PStrOffset {
-                            self.iter.push_stack(end_h);
+                            self.iter.push_stack(IterStackLoc::iterable_loc(end_h, HeapOrStackTag::Heap));
                         }
 
                         self.state_stack.push(TokenOrRedirect::FunctorRedirect(max_depth));
@@ -1597,8 +1597,6 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
 
     pub fn print(mut self) -> Outputter {
         let spec = self.toplevel_spec.take();
-
-        self.iter.iterate_over_machine_stack(self.stack);
         self.handle_heap_term(spec, false, self.max_depth);
 
         while let Some(loc_data) = self.state_stack.pop() {
@@ -1670,7 +1668,7 @@ mod tests {
             let printer = HCPrinter::new(
                 &mut wam.machine_st.heap,
                 &mut wam.machine_st.atom_tbl,
-                &wam.machine_st.stack,
+                &mut wam.machine_st.stack,
                 &wam.op_dir,
                 PrinterOutputter::new(),
                 heap_loc_as_cell!(0)
@@ -1699,7 +1697,7 @@ mod tests {
             let printer = HCPrinter::new(
                 &mut wam.machine_st.heap,
                 &mut wam.machine_st.atom_tbl,
-                &wam.machine_st.stack,
+                &mut wam.machine_st.stack,
                 &wam.op_dir,
                 PrinterOutputter::new(),
                 heap_loc_as_cell!(0)
@@ -1723,7 +1721,7 @@ mod tests {
             let printer = HCPrinter::new(
                 &mut wam.machine_st.heap,
                 &mut wam.machine_st.atom_tbl,
-                &wam.machine_st.stack,
+                &mut wam.machine_st.stack,
                 &wam.op_dir,
                 PrinterOutputter::new(),
                 heap_loc_as_cell!(0)
@@ -1736,7 +1734,7 @@ mod tests {
             let mut printer = HCPrinter::new(
                 &mut wam.machine_st.heap,
                 &mut wam.machine_st.atom_tbl,
-                &wam.machine_st.stack,
+                &mut wam.machine_st.stack,
                 &wam.op_dir,
                 PrinterOutputter::new(),
                 heap_loc_as_cell!(0)
@@ -1769,7 +1767,7 @@ mod tests {
             let printer = HCPrinter::new(
                 &mut wam.machine_st.heap,
                 &mut wam.machine_st.atom_tbl,
-                &wam.machine_st.stack,
+                &mut wam.machine_st.stack,
                 &wam.op_dir,
                 PrinterOutputter::new(),
                 heap_loc_as_cell!(0),
@@ -1788,7 +1786,7 @@ mod tests {
             let printer = HCPrinter::new(
                 &mut wam.machine_st.heap,
                 &mut wam.machine_st.atom_tbl,
-                &wam.machine_st.stack,
+                &mut wam.machine_st.stack,
                 &wam.op_dir,
                 PrinterOutputter::new(),
                 heap_loc_as_cell!(0),
@@ -1805,7 +1803,7 @@ mod tests {
             let mut printer = HCPrinter::new(
                 &mut wam.machine_st.heap,
                 &mut wam.machine_st.atom_tbl,
-                &wam.machine_st.stack,
+                &mut wam.machine_st.stack,
                 &wam.op_dir,
                 PrinterOutputter::new(),
                 heap_loc_as_cell!(0)
@@ -1837,7 +1835,7 @@ mod tests {
             let mut printer = HCPrinter::new(
                 &mut wam.machine_st.heap,
                 &mut wam.machine_st.atom_tbl,
-                &wam.machine_st.stack,
+                &mut wam.machine_st.stack,
                 &wam.op_dir,
                 PrinterOutputter::new(),
                 heap_loc_as_cell!(0)
@@ -1860,7 +1858,7 @@ mod tests {
             let printer = HCPrinter::new(
                 &mut wam.machine_st.heap,
                 &mut wam.machine_st.atom_tbl,
-                &wam.machine_st.stack,
+                &mut wam.machine_st.stack,
                 &wam.op_dir,
                 PrinterOutputter::new(),
                 pstr_loc_as_cell!(0)
@@ -1888,7 +1886,7 @@ mod tests {
             let printer = HCPrinter::new(
                 &mut wam.machine_st.heap,
                 &mut wam.machine_st.atom_tbl,
-                &wam.machine_st.stack,
+                &mut wam.machine_st.stack,
                 &wam.op_dir,
                 PrinterOutputter::new(),
                 heap_loc_as_cell!(0),

diff --git a/src/machine/arithmetic_ops.rs b/src/machine/arithmetic_ops.rs
index 774b848f0730dce7186d8905ffba78c2f53de90e..f5aa982f5839995523eebb421603565f246c7279 100644 (file)
--- a/src/machine/arithmetic_ops.rs
+++ b/src/machine/arithmetic_ops.rs
@@ -1106,7 +1106,7 @@ impl MachineState {
 
     pub(crate) fn arith_eval_by_metacall(&mut self, value: HeapCellValue) -> Result<Number, MachineStub> {
         let stub_gen = || functor_stub(atom!("is"), 2);
-        let mut iter = stackful_post_order_iter(&mut self.heap, value);
+        let mut iter = stackful_post_order_iter(&mut self.heap, &mut self.stack, value);
 
         while let Some(value) = iter.next() {
             if value.get_forwarding_bit() {

diff --git a/src/machine/attributed_variables.rs b/src/machine/attributed_variables.rs
index 57ea1c225380454b5ae3873a77b16c8ad1c5ea57..633378a0cea82f6ad6a7b8b32633edb232207f45 100644 (file)
--- a/src/machine/attributed_variables.rs
+++ b/src/machine/attributed_variables.rs
@@ -136,7 +136,7 @@ impl MachineState {
         let mut seen_set = IndexSet::new();
         let mut seen_vars = vec![];
 
-        let mut iter = stackful_preorder_iter(&mut self.heap, cell);
+        let mut iter = stackful_preorder_iter(&mut self.heap, &mut self.stack, cell);
 
         while let Some(value) = iter.next() {
             read_heap_cell!(value,
@@ -147,7 +147,7 @@ impl MachineState {
 
                     let value = unmark_cell_bits!(value);
 
-                    if h != iter.focus() {
+                    if h != iter.focus().value() as usize {
                         let deref_value = heap_bound_store(iter.heap, heap_bound_deref(iter.heap, value));
 
                         if deref_value.is_compound(iter.heap) {
@@ -167,7 +167,7 @@ impl MachineState {
                     loop {
                         read_heap_cell!(iter.heap[l],
                             (HeapCellValueTag::Lis) => {
-                                iter.push_stack(l);
+                                iter.push_stack(IterStackLoc::iterable_loc(l, HeapOrStackTag::Heap));
                                 // l = elem + 1;
                                 break;
                             }

diff --git a/src/machine/gc.rs b/src/machine/gc.rs
index 8a884950cabe133896a2be1c7b89130a6c222846..1de28ffef2ec3b8b149a773b4ca3267989447eb3 100644 (file)
--- a/src/machine/gc.rs
+++ b/src/machine/gc.rs
@@ -3,7 +3,7 @@ use crate::machine::heap::*;
 use crate::types::*;
 
 #[cfg(test)]
-use crate::heap_iter::FocusedHeapIter;
+use crate::heap_iter::{IterStackLoc, FocusedHeapIter, HeapOrStackTag};
 
 use core::marker::PhantomData;
 
@@ -75,8 +75,8 @@ pub(crate) struct StacklessPreOrderHeapIter<'a, UMP: UnmarkPolicy> {
 #[cfg(test)]
 impl<'a> FocusedHeapIter for StacklessPreOrderHeapIter<'a, IteratorUMP> {
     #[inline]
-    fn focus(&self) -> usize {
-        self.current
+    fn focus(&self) -> IterStackLoc {
+        IterStackLoc::iterable_loc(self.current, HeapOrStackTag::Heap)
     }
 }
 

diff --git a/src/machine/loader.rs b/src/machine/loader.rs
index 616fe7ee207226b9e4462b28441d310e0bb2ac6e..989b963bcccf6bc40223cecc3e76c5614ba60eab 100644 (file)
--- a/src/machine/loader.rs
+++ b/src/machine/loader.rs
@@ -536,7 +536,7 @@ impl<'a, LS: LoadState<'a>> Loader<'a, LS> {
         let term_addr = machine_st[heap_term_loc];
 
         let mut term_stack = vec![];
-        let mut iter = stackful_post_order_iter(&mut machine_st.heap, term_addr);
+        let mut iter = stackful_post_order_iter(&mut machine_st.heap, &mut machine_st.stack, term_addr);
 
         while let Some(addr) = iter.next() {
             let addr = unmark_cell_bits!(addr);
@@ -568,7 +568,7 @@ impl<'a, LS: LoadState<'a>> Loader<'a, LS> {
                     term_stack.push(Term::Literal(Cell::default(), Literal::try_from(addr).unwrap()));
                 }
                 (HeapCellValueTag::Atom, (name, arity)) => {
-                    let h = iter.focus();
+                    let h = iter.focus().value() as usize;
                     let mut arity = arity;
 
                     if iter.heap.len() > h + arity + 1 {

diff --git a/src/machine/machine_state.rs b/src/machine/machine_state.rs
index 6deab8d10923542a5df55c86d2bdf5d5a783f1f6..08c12ccd9f17ae43d8d44de1f3a50f890b65cda4 100644 (file)
--- a/src/machine/machine_state.rs
+++ b/src/machine/machine_state.rs
@@ -558,10 +558,10 @@ impl MachineState {
 
                     let mut singleton_var_set: IndexMap<Ref, bool> = IndexMap::new();
 
-                    for addr in stackful_preorder_iter(&mut self.heap, term) {
-                        let addr = unmark_cell_bits!(addr);
+                    for cell in stackful_preorder_iter(&mut self.heap, &mut self.stack, term) {
+                        let cell = unmark_cell_bits!(cell);
 
-                        if let Some(var) = addr.as_var() {
+                        if let Some(var) = cell.as_var() {
                             if !singleton_var_set.contains_key(&var) {
                                 singleton_var_set.insert(var, true);
                             } else {

diff --git a/src/machine/machine_state_impl.rs b/src/machine/machine_state_impl.rs
index b457ecaeed120f934ada825d426930fe3788e157..b4dc3fea353fd0c10389216abf86eee87ea55b63 100644 (file)
--- a/src/machine/machine_state_impl.rs
+++ b/src/machine/machine_state_impl.rs
@@ -1125,7 +1125,7 @@ impl MachineState {
             return false;
         }
 
-        let mut iter = stackful_preorder_iter(&mut self.heap, value);
+        let mut iter = stackful_preorder_iter(&mut self.heap, &mut self.stack, value);
 
         while let Some(value) = iter.next() {
             if value.get_forwarding_bit() {
@@ -1626,7 +1626,7 @@ impl MachineState {
             return true;
         }
 
-        let mut iter = stackful_preorder_iter(&mut self.heap, value);
+        let mut iter = stackful_preorder_iter(&mut self.heap, &mut self.stack, value);
 
         while let Some(value) = iter.next() {
             let value = unmark_cell_bits!(value);

diff --git a/src/machine/system_calls.rs b/src/machine/system_calls.rs
index e457a611cafeb0cbe1e1b2046bf649556354cfde..61bd9b67f665e5aa5dfc17f586b9ec45f53c6732 100644 (file)
--- a/src/machine/system_calls.rs
+++ b/src/machine/system_calls.rs
@@ -532,7 +532,7 @@ impl MachineState {
         seen_set: &mut IndexSet<HeapCellValue, S>,
         value: HeapCellValue,
     ) {
-        let mut iter = stackful_preorder_iter(&mut self.heap, value);
+        let mut iter = stackful_preorder_iter(&mut self.heap, &mut self.stack, value);
 
         while let Some(value) = iter.next() {
             let value = unmark_cell_bits!(value);
@@ -722,7 +722,7 @@ impl MachineState {
         let mut seen_set = IndexSet::new();
 
         {
-            let mut iter = stackful_post_order_iter(&mut self.heap, term);
+            let mut iter = stackful_post_order_iter(&mut self.heap, &mut self.stack, term);
 
             while let Some(value) = iter.next() {
                 if iter.parent_stack_len() >= max_depth {

diff --git a/src/machine/unify.rs b/src/machine/unify.rs
index 19445fe42af8e937044da6664b6efe985870aa2d..d6401b92933c339a2bec8e122d61e8cca2051731 100644 (file)
--- a/src/machine/unify.rs
+++ b/src/machine/unify.rs
@@ -651,10 +651,12 @@ fn bind_with_occurs_check<U: Unifier>(unifier: &mut U, r: Ref, value: HeapCellVa
     let mut occurs_triggered = false;
 
     if !value.is_constant() {
-        for addr in stackful_preorder_iter(&mut unifier.heap, value) {
-            let addr = unmark_cell_bits!(addr);
+        let machine_st: &mut MachineState = unifier.deref_mut();
 
-            if let Some(inner_r) = addr.as_var() {
+        for cell in stackful_preorder_iter(&mut machine_st.heap, &mut machine_st.stack, value) {
+            let cell = unmark_cell_bits!(cell);
+
+            if let Some(inner_r) = cell.as_var() {
                 if r == inner_r {
                     occurs_triggered = true;
                     break;