Removed Python2 incompatibility

lark/parser_frontends.py

@@ -107,7 +107,7 @@ class LALR_ContextualLexer(LALR_WithLexer):
 ###}
 
 class LALR_CustomLexer(LALR_WithLexer):
-    def __init__(self, lexer_cls, lexer_conf, parser_conf, *, options=None):
+    def __init__(self, lexer_cls, lexer_conf, parser_conf, options=None):
         self.lexer = lexer_cls(self.lexer_conf)
         debug = options.debug if options else False
         self.parser = LALR_Parser(parser_conf, debug=debug)