From: Markus Triska <triska@metalevel.at>
Date: Wed, 1 Dec 2021 19:58:38 +0000 (+0100)
Subject: FIXED: retract/1 issues due to module qualification
X-Git-Tag: v0.9.0~12^2
X-Git-Url: https://git.sagredo.dev/?a=commitdiff_plain;h=48cea6efdfd17b5661cec5c04813889c5bac744f;p=scryer-prolog.git

FIXED: retract/1 issues due to module qualification

This addresses #1125.
---

diff --git a/src/lib/builtins.pl b/src/lib/builtins.pl
index e3bd22a6..00a26238 100644
--- a/src/lib/builtins.pl
+++ b/src/lib/builtins.pl
@@ -998,14 +998,14 @@ retract_clause(Head, Body) :-
 
 :- meta_predicate retract(0).
 
-retract(Clause) :-
-    (  Clause \= (_ :- _) ->
-       Head = Clause,
-       Body = true,
-       retract_clause(Head, Body)
-    ;  Clause = (Head :- Body) ->
-       retract_clause(Head, Body)
-    ).
+retract(Clause0) :-
+    strip_module(Clause0, Module, Clause),
+    (   Clause = (Head :- Body) ->
+        true
+    ;   Head = Clause,
+        Body = true
+    ),
+    retract_clause(Module:Head, Body).
 
 
 :- meta_predicate retractall(0).