Changeset 4216 for trunk/library/list1.lgt

Timestamp:

04/22/08 08:09:59 (6 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/list1.lgt (modified) (1 diff)

trunk/library/list1.lgt

@@ -4 +4 @@
 
     :- info([
-        version is 1.01,
+        version is 1.1,
         author is 'Paulo Moura',
-        date is 2006/4/25,
+        date is 2008/4/22,
         comment is 'List predicates with elements constrained to a single type.']).
 
-    valid(List) :-
-        nonvar(List),
+    valid(-) :-     % catch variables and lists with unbound tails
+        !,
+        fail.
+    valid([]).
+    valid([Element| List]) :-
         parameter(1, Type),
-        \+ \+ valid(List, Type).
-
-    valid([], _).
-    valid([Value| List], Type) :-
-        Type::valid(Value),
-        valid(List, Type).
+        Type::valid(Element),
+        valid(List).
 
 :- end_object.