1 files changed, 63 insertions, 0 deletions

diff --git a/builtins.c b/builtins.c
index b33bc49..9699de1 100644
--- a/builtins.c
+++ b/builtins.c
@@ -63,6 +63,9 @@ BuiltinProto(builtincharcode);
 BuiltinProto(builtinchoicestacksize);
 BuiltinProto(builtincollectgarbage);
 BuiltinProto(builtinloadmodulefromfile);
+BuiltinProto(builtinflushoutput);
+BuiltinProto(builtinstreamproperties);
+BuiltinProto(builtinsetstreamposition);
 
 int compareterms(Term *, Term *);
 
@@ -178,6 +181,12 @@ findbuiltin(Term *goal)
 		return builtincollectgarbage;
 	if(Match(L"$load_module_from_file", 1))
 		return builtinloadmodulefromfile;
+	if(Match(L"flush_output", 1))
+		return builtinflushoutput;
+	if(Match(L"stream_properties", 1))
+		return builtinstreamproperties;
+	if(Match(L"set_stream_position", 2))
+		return builtinsetstreamposition;
 
 	return nil;
 }
@@ -1445,4 +1454,58 @@ builtinloadmodulefromfile(Term *goal, Binding **bindings, Module *module)
 		return 1;
 	else
 		return 0;
+}
+
+int
+builtinflushoutput(Term *goal, Binding **bindings, Module *module)
+{
+	USED(bindings);
+	USED(module);
+	Term *s = goal->children;
+
+	if(s->tag == VariableTerm)
+		Throw(instantiationerror());
+	if(s->tag != IntegerTerm && s->tag != AtomTerm)
+		Throw(domainerror(L"stream_or_alias", s));
+	if(!isopenstream(s))
+		Throw(existenceerror(L"stream", s));
+	if(!isoutputstream(s))
+		Throw(permissionerror(L"output", L"stream", s));
+
+	flushstream(s);
+	return 1;
+}
+
+int
+builtinstreamproperties(Term *goal, Binding **bindings, Module *module)
+{
+	USED(module);
+	USED(bindings);
+	Term *props = goal->children;
+	Term *list = streamsproperties();
+	Term *realprops = mklist(list);
+	return unify(props, realprops, bindings);
+}
+
+int
+builtinsetstreamposition(Term *goal, Binding **bindings, Module *module)
+{
+	USED(module);
+	USED(bindings);
+	Term *s = goal->children;
+	Term *pos = s->next;
+
+	if(s->tag == VariableTerm || pos->tag == VariableTerm)
+		Throw(instantiationerror());
+	if(s->tag != IntegerTerm && s->tag != AtomTerm)
+		Throw(domainerror(L"stream_or_alias", s));
+	if(pos->tag != IntegerTerm || pos->ival < 0)
+		Throw(domainerror(L"stream_position", pos));
+	if(!isopenstream(s))
+		Throw(existenceerror(L"stream", s));
+	if(!canreposition(s))
+		Throw(permissionerror(L"reposition", L"stream", s));
+
+	reposition(s, pos->ival);
+	return 1;
 }
\ No newline at end of file