Hi All, I wrote a program which permutates a list words with some rules. For example if I feed it a list like: banana waterloo vraag It gives back the list: banana b@nana ban@na b@n@na banan@ b@nan@ ban@n@ b@n@n@ waterloo wa+erloo water|oo waterl0o etc However I have the feeling I am doing things to complicated. I am still a beginner. Would someone like to help me simplify somethings. If you think this is inappropriate please state also. I am not offended then. I understand you are offering your spare time to help me. The first thing I don't get is this. I recognize some things could be rewritten with a bind operator (because of the concat $ fmap), but I am puzzled how: mutateWords :: [Char] -> [[Char]] mutateWords word = nub.concat $ fmap snd <$> fmap unzip <$> ( foldr(\x z -> let char = snd x nm = number word lst = fst x in (insertAt char nm <$> lst) : z ) [[]] $ mw word ) Here is the full code: import Data.List import System import System.IO import Control.Applicative ---CONFIG section leat = ['s' ==> '$', 't' ==> '+', 'l' ==> '|', 'o' ==> '0','e' ==> '3', 'a' ==> '@', 'v' ==> '^'] leata = fst.unzip $ leat leatb = snd.unzip $ leat -- Perl like assoc lists infixl 1 ==> a ==> b = (a, b) -- Flipped fmap sometimes nicer infixl 4 <$$> xs <$$> f = f <$> xs -- first I need to find the positions of the mutatable charachters. findPositions :: [Char] -> [[Int]] findPositions xs = take (length index) $ index <*> [xs] where index = elemIndices <$> leata -- And generate all subsequences findSubSeq :: [Char] -> [[[Int]]] findSubSeq = fmap subsequences <$> findPositions -- Only change elements which needs to be changed insertAt :: Char -> [(Int, Char)] -> [Int] -> [(Int,Char)] insertAt c xs ps = xs <$$> (\x -> if (fst x) `elem` ps then (fst x , c) else x ) -- Couples character to mutable positions mw word = (findSubSeq word) `zip` leatb number = zip [0..] mutateWords :: [Char] -> [[Char]] mutateWords word = nub.concat $ fmap snd <$> fmap unzip <$> ( foldr(\x z -> let char = snd x nm = number word lst = fst x in (insertAt char nm <$> lst) : z ) [[]] $ mw word ) generateAll :: [Char] -> [[Char]] generateAll word = g lea $ mutateWords word where g 0 words = words g n words = g (n - 1) (nub $ words >>= mutateWords ) lea = length leata main = do filename <- getArgs wordlist <- readFile $ filename !! 0 let a = (words wordlist) >>= generateAll mapM_ putStrLn a -- Flatliner ICT Service, Email: Edgar.klerks@gmail.com, Tel: +31727851429 Fax: +31848363080 Skype: edgar.klerks Website: flatlinerict.nl Adres: Koelmalaan 258, 1813JD, Alkmaar Nederland