Resolved some remaining chicken and egg when parsing BNF nodes

src/core/sheerka/ExecutionContext.py

@@ -373,15 +373,15 @@ class ExecutionContext:
         :param predicate: what execution context to keep
         :param get_obj: lambda to compute what to return
         :param start_with_self: include the current execution context in the search
-        :param stop: stop the search if matched
+        :param stop: condition to stop
         :return:
         """
         current = self if start_with_self else self._parent
         while current:
-            if stop and stop(current):
-                break
-
             if predicate is None or predicate(current):
                 yield current if get_obj is None else get_obj(current)
 
+            if stop and stop(current):
+                break
+
             current = current._parent