Parsing hangs even for simple ambiguous grammars

[ollef]

Parsing hangs even for simple ambiguous grammars

[ollef]

Hey, and thanks for getting in touch.

I would encourage you to read this section of the readme. Basically, you have to use rule whenever there's a recursive rule. This is what allows the Earley library to do something slightly more clever than most parser combinator libraries for recursive rules.

Your grammar should work fine if you use something along the lines of:

grammar = mdo
  s <- rule $ S <$> many a <*> b <*> many t
  t <- rule $ T <$> c <*> s
  return s

I hope that helps!

[rmanne]

Thanks! That's exactly what I needed.