7 ms·

ghc -e 'interact $ unlines . map reverse . lines'

• vertex-four 12y ago
  Or, on any *nix worth talking about, by default... perl -e 'print reverse <>'
• dbaupp 12y ago
  Isn't that `rev`, not `tac`? (I think `tac` should be `unlines . reverse . lines`.)
  • wyager 12y ago
    You are correct. For those not familiar with Haskell, unlines . map reverse . lines is the same thing as (python) lambda data : [line[::-1] for line in data] whereas unlines . reverse. lines is the same as lambda data : [line for line in data][::-1]
    • dbaupp 12y ago
      Well, you need '\n'.join(...) for the "unlines" bit.