added sum types

src/lib/objects/o_nullable.c

@@ -2,7 +2,7 @@
 #include "objects.h"
 
 static void walk(Object *self, void (*callback)(Object **referer, void *userp), void *userp);
-static bool istypeof(Object *self, Object *other);
+static bool istypeof(Object *self, Object *other, Heap *heap, Error *error);
 
 typedef struct {
     Object  base;
@@ -47,16 +47,18 @@ Object *Object_NewNullable(Object *item, Heap *heap, Error *error)
 
 static bool 
 istypeof(Object *self, 
-         Object *other)
+         Object *other, 
+         Heap   *heap, 
+         Error  *error)
 {
     NullableObject *nullable = (NullableObject*) self;
     if (Object_IsNone(other))
         return true;
-    return Object_IsTypeOf(nullable->item, other);
+    return Object_IsTypeOf(nullable->item, other, heap, error);
 }
 
 static void walk(Object *self, void (*callback)(Object **referer, void *userp), void *userp)
 {
     NullableObject *nullable = (NullableObject*) self;
     callback(&nullable->item, userp);
-}
+}