1 files changed, 17 insertions, 0 deletions
diff --git a/builtins.c b/builtins.c
index d1f70b9..79c71f0 100644
--- a/builtins.c
+++ b/builtins.c
@@ -70,6 +70,7 @@ BuiltinProto(builtinsetstreamposition);
 BuiltinProto(builtinop);
 BuiltinProto(builtincurrentops);
 BuiltinProto(builtinnewemptymodule);
+BuiltinProto(builtinhalt);
 
 int compareterms(Term *, Term *);
 
@@ -199,6 +200,8 @@ findbuiltin(Term *goal)
 		return builtincurrentops;
 	if(Match(L"$new_empty_module", 1))
 		return builtinnewemptymodule;
+	if(Match(L"$halt", 1))
+		return builtinhalt;
 
 	return nil;
 }
@@ -1649,3 +1652,17 @@ builtinnewemptymodule(Term *goal, Binding **bindings, Module *module)
 	addemptymodule(name);
 	return 1;
 }
+
+int
+builtinhalt(Term *goal, Binding **bindings, Module *module)
+{
+	USED(bindings);
+	USED(module);
+	vlong exitcode = goal->children->ival;
+	char *msg = nil;
+	if(exitcode != 0)
+		msg = smprint("pprolog exit code: %lld\n", exitcode);
+
+	exits(msg);
+	return 1;
+}