Bugfix #25: Ambiguity resolver sometimes failed under Python3

2017-09-14 01:04:34 +03:00 · 2017-09-14 01:04:34 +03:00 · 5c02166c3f
parent 063c7fbdab
commit 5c02166c3f
1 changed files with 4 additions and 1 deletions
--- a/lark/parsers/resolve_ambig.py
+++ b/lark/parsers/resolve_ambig.py
@ -24,7 +24,10 @@ def _compare_rules(rule1, rule2):

 def _compare_drv(tree1, tree2):
    if not (isinstance(tree1, Tree) and isinstance(tree2, Tree)):
-        return -compare(tree1, tree2)
+        try:
+            return -compare(tree1, tree2)
+        except TypeError:
+            return 0

    try:
        rule1, rule2 = tree1.rule, tree2.rule