add randomness predicates, small but consequential changes to TrailRef

2019-10-17 00:21:21 -06:00
parent a641822a1b
commit ab9a14cc6a
6 changed files with 99 additions and 17 deletions
--- a/src/prolog/machine/machine_indices.rs
+++ b/src/prolog/machine/machine_indices.rs
@@ -178,10 +178,11 @@ impl From<Ref> for Addr {
    }
 }

-#[derive(Clone)]
+#[derive(Clone, Copy)]
 pub enum TrailRef {
    Ref(Ref),
-    AttrVarLink(usize, Addr),
+    AttrVarHeapLink(usize),
+    AttrVarListLink(usize, usize),
 }

 impl From<Ref> for TrailRef {