Re: [Haskell-cafe] Parsing words with parsec
On Friday 30 March 2007 06:59, Stefan O'Rear wrote: Anyway, I think parsec is *far* too big a hammer for the nail you're trying to hit. In the end , the big hammer solution has become parseLine = fmap (map fst. filter snd) $ many parser where parser = do w - option (,False) parseAWord anyChar -- skip the separator return w parseAWord = try positive | (many1 nonSeparator return (,False)) positive = do c - wordChar (cs,tn) - option (,True) parseAWord return (c:cs,tn) wordChar = letter | oneOf _@ ? a word-character nonSeparator = wordChar | digit ? a non-separator while your, corrected not parsec solution is wordsOfLine isNonSeparator isWordChar = (filter (all isWordChar)). groupBy (\x y - (isNonSeparator x) == (isNonSeparator y)) Still ,I wonder if the parsec solution can be simplified. Thanks. (PS. I put an option on the ML software which sends me an ack on posting , so at least I know I sent the mail :) ) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Parsing words with parsec
On 3/30/07, Stefan O'Rear [EMAIL PROTECTED] wrote: On Fri, Mar 30, 2007 at 05:43:34AM +0200, paolino wrote: Hi, I had a bad time trying to parse the words of a text. I suspect I miss some parsec knowledge. I'd start by not sextuple-posting, it just sextuples the ugliness ;-) Mhh, still I don't see any them in my inbox mails , probably something buggy in gmail configuration, sorry :/. import Char( isAlpha ) import List( groupBy ) equating f x y = f x == f y -- in Data.Eq, iff you have GHC 6.7 isLetter x = isAlpha x || x == '_' || x == '@' myWords = filter (isLetter . head) . groupBy (equating isLetter) Testing your code, it misses the words with numbers inside exclusion and uses the number as separators. !runhaskell prova.hs [[EMAIL PROTECTED],sara,mimmo,ab,a,b,ab,cd] Thanks ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Parsing words with parsec
Hi, I had a bad time trying to parse the words of a text. I suspect I miss some parsec knowledge. In the end it seems working, though I haven't tested much and this example contains the main features I was looking. *Main parseTest (parseLine eof) [EMAIL PROTECTED] sara,mimmo! 9ab a9b ab9 cd\n [[EMAIL PROTECTED],sara,mimmo,cd] - manyTillT body terminator joiner = liftM2 joiner (manyTill body (lookAhead terminator)) terminator wordChar = letter | oneOf _@ ? a valid word character nonSeparator = wordChar | digit wordEnd = do x - wordChar notFollowedBy nonSeparator return x word = manyTillT wordChar (try wordEnd) (\b t - b ++ [t]) ? a word wordStart = do (try nonSeparator unexpected non separator) | anyChar lookAhead wordChar nextWord = manyTill anyChar (try wordStart) (try word | nextWord) parseLine end = do f - option [] $ return `fmap` try word r - many $ try nextWord manyTill anyChar end return (f ++ r) --- Any comment to simplify this code is welcome. Paolino. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Parsing words with parsec
Hi, I had a bad time trying to parse the words of a text. I suspect I miss some parsec knowledge. In the end it seems working, though I haven't tested much and this example contains the main features I was looking. *Main parseTest (parseLine eof) [EMAIL PROTECTED] sara,mimmo! 9ab a9b ab9 cd\n [[EMAIL PROTECTED],sara,mimmo,cd] - manyTillT body terminator joiner = liftM2 joiner (manyTill body (lookAhead terminator)) terminator wordChar = letter | oneOf _@ ? a valid word character nonSeparator = wordChar | digit wordEnd = do x - wordChar notFollowedBy nonSeparator return x word = manyTillT wordChar (try wordEnd) (\b t - b ++ [t]) ? a word wordStart = do (try nonSeparator unexpected non separator) | anyChar lookAhead wordChar nextWord = manyTill anyChar (try wordStart) (try word | nextWord) parseLine end = do f - option [] $ return `fmap` try word r - many $ try nextWord manyTill anyChar end return (f ++ r) --- Any comment to simplify this code is welcome. Paolino. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
