import Text.Regex.Posix import Data.Char import Data.List guessKeys line = concat $ intersperse "-" (modifiers ++ [map toLower key]) where modifiers = map (!!1) (line =~ "(mod|shift|control)Mask") (_, _, _, [key]) = line =~ "xK_(\\w+)" :: (String, String, String, [String]) aaa line = map (!!1) (line =~ "(mod|shift|control)Mask") bbb line = line =~ "xK_(\\w+)" :: (String, String, String, [String]) In ghci

guessKeys "modF1" "*** Exception: Test.hs:8:10-85: Irrefutable pattern failed for pattern (_, _, _ , [key])

aaa "modF1" <interactive>:1:0: No instance for (Text.Regex.Base.RegexLike.RegexContext Regex [Char] [[a]]) arising from a use of `aaa' at <interactive>:1:0-10

bbb "modF1" ("modF1","","",[])

I just extract the functions from where clause of guessKeys. But why are there different running result ? Sincerely! ----- fac n = foldr (*) 1 [1..n] -- View this message in context: http://old.nabble.com/About-Regex-question-tp26211696p26211696.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.