Fix #1345 by not calling the callbacks from InteractiveParser.accepts

lark/parsers/lalr_interactive_parser.py

@@ -102,9 +102,14 @@ def choices(self):
     def accepts(self):
         """Returns the set of possible tokens that will advance the parser into a new valid state."""
         accepts = set()
+        conf_no_callbacks = copy(self.parser_state.parse_conf)
+        # We don't want to call callbacks here since those might have arbitrary side effects
+        # and are unnecessarily slow.
+        conf_no_callbacks.callbacks = {}
         for t in self.choices():
             if t.isupper(): # is terminal?
                 new_cursor = copy(self)
+                new_cursor.parser_state.parse_conf = conf_no_callbacks
                 try:
                     new_cursor.feed_token(self.lexer_thread._Token(t, ''))
                 except UnexpectedToken:

lark/parsers/lalr_parser.py

@@ -147,7 +147,7 @@ def feed_token(self, token, is_end=False):
                 else:
                     s = []
 
-                value = callbacks[rule](s)
+                value = callbacks[rule](s) if callbacks else s
 
                 _action, new_state = states[state_stack[-1]][rule.origin.name]
                 assert _action is Shift