Weird bind implementation? about parsy HOT 7 OPEN

Related: I seem to have to define wrap something like the following to get backtracking to work?

def wrap(fn):
  def thing(res):
    try:
      result = fn.parse(res)
      return success(result)
    except:
      return fail("idk")
  return thing

What's the correct way to do this?

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@jneen do you have any input on this? I've never actually used bind directly, perhaps you could answer this question more easily than me?

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Ok, this makes more sense when used like in #36 (comment) , I need to revisit this later.

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I'm not sure what you're trying to do, could you explain in a little more detail? The "pseudocode" example you gave passes a Parser instance to .bind - but .bind takes a function that returns a parser. It's a little hard to follow because your variable named fn is not actually a function, but a parser.

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Oh, I think I see what's happening. You are mixing strings and tokens, and want to "re-parse" the parse result when it's not a token. I... would suggest just tokenizing your entire input before passing it to parsy if that's the direction you want to go.

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If you are really dedicated to this approach you might want to define something like:

def reparse(parser):
    return test_item(lambda x: isinstance(x, unicode), 'not a string').map(parser.parse)

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@spookylukey for reference, bind is just a way to dynamically determine the next parser, which you can naturally do with @generate functions. These are equivalent:

parser = first.bind(second)

@generate
def parser():
    res = yield first
    return (yield second(res))

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