unify might bound a multi-assignment variable?\027?\024

git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@480 b08c6af1-5177-4d33-ba66-4b1c6b8b522a

H/amiops.h

@@ -371,10 +371,28 @@ Int unify(Term t0, Term t1)
     return(TRUE);
   } else {
     while(TR != TR0) {
-      CELL *p;
+      CELL d1;
       --TR;
-      p = (CELL *)TrailTerm(TR);
-      RESET_VARIABLE(p);
+      d1 = TrailTerm(TR);
+#ifdef MULTI_ASSIGNMENT_VARIABLES
+      if (IsVarTerm(d1)) {
+#endif
+	CELL *pt = (CELL *)d1;
+	RESET_VARIABLE(pt);
+#ifdef MULTI_ASSIGNMENT_VARIABLES
+      } else {
+	  CELL *pt = RepAppl(d1);
+	  /* AbsAppl means */
+	  /* multi-assignment variable */
+	  /* so the next cell is the old value */ 
+	  TR--;
+#if FROZEN_STACKS
+	  pt[0] = TrailVal(TR);
+#else
+	  pt[0] = TrailTerm(TR);
+#endif
+      }
+#endif
     }
     return(FALSE);
   }

docs/yap.tex

@@ -2291,7 +2291,7 @@ over @var{G}.
 If you want @var{G} to be deterministic you should use if-then-else, as
 it is both more efficient and more portable.
 
-@item once(+@var{G}) [IS0]
+@item once(:@var{G}) [IS0]
 @findex once/1
 @snindex once/1
 @cnindex once/1
@@ -4668,7 +4668,7 @@ long as they are not currently in use.
  Deletes the predicate with name @var{P} and arity @var{N}. It will remove
 both static and dynamic predicates.
 
-@item assert_static(+@var{C})
+@item assert_static(:@var{C})
 @findex assert_static/1
 @snindex assert_static/1
 @cnindex assert_static/1
@@ -4676,13 +4676,13 @@ both static and dynamic predicates.
 for a predicate while choice-points for the predicate are availabe has
 undefined results.
 
-@item asserta_static(+@var{C})
+@item asserta_static(:@var{C})
 @findex asserta_static/1
 @snindex asserta_static/1
 @cnindex asserta_static/1
  Adds clause @var{C} to the beginning of a static procedure. 
 
-@item assertz_static(+@var{C})
+@item assertz_static(:@var{C})
 @findex assertz_static/1
 @snindex assertz_static/1
 @cnindex assertz_static/1

pl/modules.yap

@@ -530,10 +530,13 @@ source_module(Mod) :-
 	all(?,:,?),
 	assert(:),
 	assert(:,+),
+	assert_static(:),
 	asserta(:),
 	asserta(:,+),
+	asserta_static(:),
 	assertz(:),
 	assertz(:,+),
+	assertz_static(:),
 	bagof(?,:,?),
 	bb_get(:,-),
 	bb_put(:,+),
@@ -565,6 +568,7 @@ source_module(Mod) :-
 	listing(:),
 	nospy(:),
         not(:),
+        once(:),
         phrase(:,?),
         phrase(:,?,+),
 	predicate_property(:,?),