Re: [Haskell-cafe] Parsers (Parsec and Iteratee-based Parsers)

2010/1/12 Günther Schmidt :

Hi John,

thanks for responding. As I said I've been using Parsec quite a lot, but wonder if there is a different approach possible/feasible to parsing. Parsec (2x) isn't an "online" parser, ie, it doesn't produce a result before the whole parse is completed.

This appears to be a common source of confusion. You can produce a result by not trying to parse the entire input in one go, instead parse as much as you want to consume, then return the rest of the input with the tokens that you have collected. For example, in Parsec 2 a regular approach I use is something like: get1 = do token <- parse1token remaining <- getInput return (remaining,token) Jeff