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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal>I have the following code snippet:<o:p></o:p></p><p class=MsoNormal>import System.IO<o:p></o:p></p><p class=MsoNormal>import Data.String.Utils <o:p></o:p></p><p class=MsoNormal><o:p></o:p></p><p class=MsoNormal>main = withFile "test.txt" ReadMode $ \handle -> do<o:p></o:p></p><p class=MsoNormal> xs <- getwords handle<o:p></o:p></p><p class=MsoNormal> sequence_ $ map putStrLn (escapeRe xs)<o:p></o:p></p><p class=MsoNormal><o:p></o:p></p><p class=MsoNormal>getwords :: Handle -> IO [String]<o:p></o:p></p><p class=MsoNormal>getwords h = hGetContents h >>= return . words<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>What I want to to there is to get i.e. “word,” or “word!” etc. and arrive at “word”. I understand that escapeRe may do this. However, I always get some sort of mismatch errors like this:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>test.hs:6:38:<o:p></o:p></p><p class=MsoNormal> Couldn't match type `Char' with `[Char]'<o:p></o:p></p><p class=MsoNormal> Expected type: [String]<o:p></o:p></p><p class=MsoNormal> Actual type: String<o:p></o:p></p><p class=MsoNormal> In the return type of a call of `escapeRe'<o:p></o:p></p><p class=MsoNormal> In the second argument of `map', namely `(escapeRe xs)'<o:p></o:p></p><p class=MsoNormal> In the second argument of `($)', namely<o:p></o:p></p><p class=MsoNormal> `map putStrLn (escapeRe xs)'<o:p></o:p></p><p class=MsoNormal><o:p></o:p></p><p class=MsoNormal>test.hs:6:47:<o:p></o:p></p><p class=MsoNormal> Couldn't match type `[Char]' with `Char'<o:p></o:p></p><p class=MsoNormal> Expected type: String<o:p></o:p></p><p class=MsoNormal> Actual type: [String]<o:p></o:p></p><p class=MsoNormal> In the first argument of `escapeRe', namely `xs'<o:p></o:p></p><p class=MsoNormal> In the second argument of `map', namely `(escapeRe xs)'<o:p></o:p></p><p class=MsoNormal> In the second argument of `($)', namely<o:p></o:p></p><p class=MsoNormal> `map putStrLn (escapeRe xs)'<o:p></o:p></p><p class=MsoNormal><o:p></o:p></p><p class=MsoNormal>Now I have three questions:<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>1.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>Is escapeRe the right function to use here?<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>2.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>What do I do wrong?<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>3.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>I read in the Real World Haskell book that actually all these file/string operations are very very slow. The recommendation is to work with bytestrings instead. Is there any (fast) way to strip non-alphanumericals from bytestrings?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks,<o:p></o:p></p><p class=MsoNormal>--Joerg<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>