(list_comparator_t): New datatype.

(list_set_comparator): New function

@@ -38,6 +38,9 @@ typedef int list_action_t __PMT ((void* item, void* cbdata));
   
 extern int list_do       __P ((list_t list, list_action_t * action, void *cbdata));
 
+typedef int (*list_comparator_t) __PMT((const void*, const void*));
+
+extern list_comparator_t list_set_comparator __P((list_t, list_comparator_t));
   
 #ifdef __cplusplus
 }