py: Add MP_OBJ_STOP_ITERATION and make good use of it.

Also make consistent use of MP_OBJ_NOT_SUPPORTED and MP_OBJ_NULL.
This helps a lot in debugging and understanding of function API.

1 files changed, 1 insertions, 1 deletions

diff --git a/py/objrange.c b/py/objrange.c
index 45f83580d..7815a5951 100644
--- a/py/objrange.c
+++ b/py/objrange.c
@@ -25,7 +25,7 @@ STATIC mp_obj_t range_it_iternext(mp_obj_t o_in) {
         o->cur += o->step;
         return o_out;
     } else {
-        return MP_OBJ_NULL;
+        return MP_OBJ_STOP_ITERATION;
     }
 }