Hi Neil, This is awesome, thank you. :-) It found a 'use liftM', 'use on' and three eta-reduces in Yogurt. It seems like the line numbers could be a bit more accurate: ./Network/Yogurt/IO.hs:54:3: Use liftM Found: rec >>= return . (c :) Why not: liftM (c :) rec Where the code is: 50 -- Waits for input, but once the first character is read, waits 51 -- no longer than the specified number of ms before giving up. 52 hGetImpatientLine :: Handle -> Int -> IO String 53 hGetImpatientLine h patience = rec where 54 rec = do 55 c <- hGetChar h 56 if c == '\n' 57 then return [c] 58 else do 59 b <- hWaitForInput h patience 60 if b 61 then rec >>= return . (c:) 62 else return [c] I imagine it could have told me to look at line 61 right away. Thanks, Martijn.