in reply to Re: Backtracking in Parse::RecDescent (solution)
in thread Backtracking in Parse::RecDescent

Thanks, that's a good answer. However, it does not quite do what I want, which is for the parser to try all possible alternatives in a production before failing. I suspect that the answer is that top-down parsers just do not work that way.
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Re: Re: Re: Backtracking in Parse::RecDescent (solution)
by Anonymous Monk on Dec 07, 2002 at 01:47 UTC
    The answer is that RecDescent parsers do not work that way. They don't backtrack on failure; they just fail. Of course, there's nothing to prevent a recursive descent parser from incorporating backtracking too, but RecDescent doesn't.

    So, if you need backtracking in part of your grammar, you need to use plain old regexes there. Sorry.

    Damian

[reply]
      Thanks Damian. It's one thing to suspect an explanation; quite another to have it confirmed :)

      Kevin

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