I got asked how to do one particular thing in excel, which led to discssion with "our local MSOffice expert". During the discussion I stated that's it too much of a PITA and that I'd rather write a script. Long story short, I promised him a one-liner to "show the power and beauty of Haskell". I got the csv package from hackage, modified the parseCSVFromFile so it's returns IO CSV rather than IO (Either ParseError CSV), and finished with following code (writeFile "output.csv") =<< (liftM printCSV $ liftM (map updateLine) $ parseCSVFromFile "input.csv") Is there room for improvement ? Could it still be made into one-liner without modifying the csv module (and without resorting to case parseCSVFromFile "input.csv" of { Left _ -> []; Right x -> x} kind of tricks) ? Thanks, wman.