FIzz Buzz kata in haskell

FizzBuzz.hs

module FizzBuzz where
  
import Data.Maybe
import Data.List
import Data.Char (digitToInt)

type Rule = Int -> Maybe String

fizz = oR (word 3 "fizz") (contains 3 "fizz")
buzz = word 5 "buzz"
ticino = word 7 "ticino"
rules = [fizz, buzz, ticino]

oR :: Rule -> Rule -> Rule
oR x y = \n -> combineK [x, y] n
  where combineK [] _ = Nothing
        combineK (r:rs) n = if isJust (r n) then (r n) else combineK rs n

word :: Int -> String -> Rule
word d w = \n -> if n `mod` d == 0 then Just w else Nothing

contains :: Int -> String -> Rule
contains d w = \n -> if d `elem` (toDigits n) then Just w else Nothing
  where toDigits = map digitToInt . show

render :: Int -> String
render n = getOrElse folDMap n

folDMap :: Int -> Maybe String
folDMap x = if concats == "" then Nothing else Just concats
  where concats = foldMap (maybe "" id) (ruleResults x)
        ruleResults = (\x -> map (\f -> f x) rules)

getOrElse :: Rule -> Int -> String
getOrElse f x = if isJust (f x) then fromJust (f x) else show x

start = map render [1..49]