FizzBuzz.hs

module FizzBuzz where
import           Data.Maybe

data FizzBuzz = Fizz | Buzz deriving Show

whenDivisible :: Integral a => a -> b -> a -> Maybe b
whenDivisible d x n = if n `rem` d == 0 then Just x else Nothing

fizzbuzz :: (Show a, Integral a) => a -> String
fizzbuzz n = if null tags then show n else concatMap show tags
  where tags = catMaybes [fizz n, buzz n]
        fizz = whenDivisible 3 Fizz
        buzz = whenDivisible 5 Buzz

main = mapM_ (putStrLn . fizzbuzz) [1..50]