ENHANCED: Performance of nth1/3 and nth0/3 for mode (-,+,?)

SWI-Prolog · Sep 4, 2023 · b1ad4aa · b1ad4aa
1 parent 5310dab
commit b1ad4aa
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/library/lists.pl b/library/lists.pl
@@ -279,7 +279,7 @@
 
 nth_gen(_, Elem, Elem, Base, Base).
 nth_gen([H|Tail], Elem, _, N, Base) :-
-    succ(N, M),
+    M is N + 1,
     nth_gen(Tail, Elem, H, M, Base).