RosettaCodeData/Task/FizzBuzz/Haskell/fizzbuzz-2.hs

fizzbuzz :: Int -> String
fizzbuzz n =
  '\n' :
  if null (fizz ++ buzz)
    then show n
    else fizz ++ buzz
  where
    fizz =
      if mod n 3 == 0
        then "Fizz"
        else ""
    buzz =
      if mod n 5 == 0
        then "Buzz"
        else ""

main :: IO ()
main = putStr $ concatMap fizzbuzz [1 .. 100]