CYK also working

lark/parser_frontends.py

@@ -194,13 +194,13 @@ class CYK(WithLexer):
         self.init_traditional_lexer()
 
         self._analysis = GrammarAnalyzer(parser_conf)
-        self._parser = cyk.Parser(parser_conf.rules, parser_conf.start)
+        self.parser = cyk.Parser(parser_conf.rules)
 
         self.callbacks = parser_conf.callbacks
 
     def parse(self, text, start):
         tokens = list(self.lex(text))
-        parse = self._parser.parse(tokens)
+        parse = self._parse(tokens, start)
         parse = self._transform(parse)
         return parse
 

lark/parsers/cyk.py

@@ -84,12 +84,11 @@ class RuleNode(object):
 class Parser(object):
     """Parser wrapper."""
 
-    def __init__(self, rules, start):
+    def __init__(self, rules):
         super(Parser, self).__init__()
         self.orig_rules = {rule: rule for rule in rules}
         rules = [self._to_rule(rule) for rule in rules]
         self.grammar = to_cnf(Grammar(rules))
-        self.start = NT(start[0])
 
     def _to_rule(self, lark_rule):
         """Converts a lark rule, (lhs, rhs, callback, options), to a Rule."""
@@ -100,13 +99,16 @@ class Parser(object):
             weight=lark_rule.options.priority if lark_rule.options and lark_rule.options.priority else 0,
             alias=lark_rule)
 
-    def parse(self, tokenized):  # pylint: disable=invalid-name
+    def parse(self, tokenized, start):  # pylint: disable=invalid-name
         """Parses input, which is a list of tokens."""
+        assert start
+        start = NT(start)
+
         table, trees = _parse(tokenized, self.grammar)
         # Check if the parse succeeded.
-        if all(r.lhs != self.start for r in table[(0, len(tokenized) - 1)]):
+        if all(r.lhs != start for r in table[(0, len(tokenized) - 1)]):
             raise ParseError('Parsing failed.')
-        parse = trees[(0, len(tokenized) - 1)][self.start]
+        parse = trees[(0, len(tokenized) - 1)][start]
         return self._to_tree(revert_cnf(parse))
 
     def _to_tree(self, rule_node):