fizzbuzzについて、パターンが増える場合に対応するケースを作ってみた #Haskell

haskellの勉強を始めたので投稿してみた

FizzBuzz.hs

module FizzBuzz where

import Data.Monoid

-- | fizzbuzzについて、パターンが増える場合に対応するケース

type ModCondition = Int
type Message = String
type FBPattern = [(ModCondition, Message)]

-- | 3:fizz 5:buzz 7:woof
-- >>> fb 1
-- "1"
-- >>> fb 3
-- "fizz"
-- >>> fb 5
-- "buzz"
-- >>> fb 7
-- "woof"
-- >>> fb 15
-- "fizzbuzz"
-- >>> fb 21
-- "fizzwoof"
-- >>> fb 35
-- "buzzwoof"
-- >>> fb 105
-- "fizzbuzzwoof"
fb :: Int -> Message
fb n = case foldl1 mappend [conv n | conv <- fbMessConvert] of
    ""    -> show n
    mess  -> mess

fbMessConvert = map getMess fbPatterns

getMess (c,m) n
    | n `mod` c == 0 = m
    | otherwise = mempty

fbPatterns :: FBPattern
fbPatterns = [(3,"fizz"),(5,"buzz"),(7,"woof")]

main :: IO()
main = print $ map fb  [1..100]