Another FizzBuzz. This time with lots of recursion.

FizzBuzz4.hs

module Main where

continue :: ([a] -> [b]) -> [a] -> [b]
continue _ []     = []
continue f (x:xs) = f (x:xs)

f1, f2, f3, b1, b2, b3, b4, b5 :: [Int] -> [(Bool, String)]

f1 (x:xs) = (False, show x):continue f2 xs
f2 (x:xs) = (False, show x):continue f3 xs
f3 (x:xs) = (True,  "Fizz"):continue f1 xs

b1 (x:xs) = (False, show x):continue b2 xs
b2 (x:xs) = (False, show x):continue b3 xs
b3 (x:xs) = (False, show x):continue b4 xs
b4 (x:xs) = (False, show x):continue b5 xs
b5 (x:xs) = (True,  "Buzz"):continue b1 xs

run :: [Int] -> [String]
run xs = zipWith go (f1 xs) (b1 xs)
  where
    go (False, s1) (False,  _) = s1
    go (True,  s1) (False,  _) = s1
    go (False,  _) (True,  s2) = s2
    go (True,  s1) (True,  s2) = s1 ++ s2

main :: IO ()
main = mapM_ putStrLn $ run [1..100]