{-# LANGUAGE LambdaCase #-}
module Main where

import Control.Monad
import System.IO

data NumberType = Normal Int
                | Fizz
                | Buzz
                | FizzBuzz

numberType :: Int -> NumberType
numberType i = case (i `mod` 3 == 0, i `mod` 5 == 0) of
  (True, False) -> Fizz
  (False, True) -> Buzz
  (True, True) -> FizzBuzz
  _ -> Normal i

main :: IO ()
main = do
  putStrLn "FizzBuzz v. 1.0.0"
  putStr "From: "
  hFlush stdout
  from <- getLine
  putStr "To: "
  hFlush stdout
  to <- getLine
  forM_ (map numberType [read from .. read to]) $ \case
    Normal i -> putStrLn $ show i
    Fizz -> putStrLn "Fizz"
    Buzz -> putStrLn "Buzz"
    FizzBuzz -> putStrLn "FizzBuzz"