Changeset 4216 for trunk/library/varlist.lgt

Timestamp:

04/22/08 08:09:59 (8 months ago)

Author:

pmoura

Message:

Updated the definitions of the predicate valid/1 for the library objects "list", "list(Type)", "numberlist", "set", "set(Type)", "varlist" to fail for lists with unbound tails after discussion with Jan Wielemaker and Ulrich Neumerkel.

Files:

• trunk/library/varlist.lgt (modified) (2 diffs)

trunk/library/varlist.lgt

@@ -4 +4 @@
 
     :- info([
-        version is 1.0,
+        version is 1.1,
         author is 'Paulo Moura',
-        date is 2000/7/24,
+        date is 2008/4/22,
         comment is 'List of variables predicates.']).
 
@@ -26 +26 @@
         prefix(Tail1, Tail2).
 
-    valid(List) :-
-        nonvar(List),
-        \+ \+ valid2(List).
-
-    valid2([]).
-    valid2([Head| Tail]) :-
-        var(Head),
-        valid2(Tail).
+    valid(-) :-     % catch variables and lists with unbound tails
+        !,
+        fail.
+    valid([]).
+    valid([Element| List]) :-
+        var(Element),
+        valid(List).
 
 :- end_object.