$ inutile avec interact

haskell/columnv7.hs

@@ -1,3 +1,3 @@
 import Data.List
-main = interact $ (unlines . map unwords . transpose . map (pad ' ') . transpose . pad "" . map words . lines)
+main = interact (unlines . map unwords . transpose . map (pad ' ') . transpose . pad "" . map words . lines)
        where pad v m = map (\e -> e ++ replicate ((maximum $ map length m)- length e) v) m