[Haskell-cafe] Parsec combinator like Prolog's cut operator?
Erik de Castro Lopo
mle+hs at mega-nerd.com
Wed Jun 30 01:20:33 EDT 2010
Antoine Latter wrote:
> For Parsec, in the absence of the "try" combinator, a parser will
> never back-track once it consumes a portion of the input.
Thanks for reminding me.
> If "try" is pushed out into the leaves of you parser, you shouldn't
> run in to too much trouble with excessive backtracking.
I agree.
> What problems are you running in to?
Unfortunately I have an existing, mostly working and quite complex
parser which does indeed use Parsec.try quite close to the root of
the tree. I have tried on a number of ocassions to refactor this
to remove this particular usage of Parsec.try without success.
Cheers,
Erik
--
----------------------------------------------------------------------
Erik de Castro Lopo
http://www.mega-nerd.com/
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