replace all occurencies of a string

replace.hs

import Data.List (tails)
import Data.List.NonEmpty (NonEmpty, toList)
import Prelude

import qualified Data.List.NonEmpty as NE

type Tries = [NonEmpty Char]

tries :: String -> Tries
tries [] = []
tries xs = fmap NE.fromList $ init $ tails xs

match :: String -> String -> Bool
match (x : xs) (y : ys) = x == y && match xs ys
match [] _ = True
match _ _ = False

matching :: String -> String -> Tries -> String
matching _pattern _replace [] = []
matching pattern' replacement (x : xs)
    | pattern' `match` toList x =
        error "TODO"
    | otherwise =
        error "TODO"
  where
    lp = length pattern' - 1

replace :: String -> String -> String -> String
replace pattern' replace' = matching pattern' replace' . tries

--- Tests ---
spec :: (Show a, Eq a) => a -> a -> IO ()
spec x y
    | x == y = pure ()
    | otherwise =
        error
            $ "Assertion failed: " <> show x <> " == " <> show y

test :: IO ()
test = do
    spec
        do replace "foo" "bar" "foo"
        do "bar"
    spec
        do replace "foo" "bar" "foobar"
        do "barbar"
    spec
        do replace "foo" "bar" "foofoo"
        do "barbar"
    spec
        do replace "foo" "bar" "barfoo"
        do "barbar"
    spec
        do replace "foo" "bar" "barbar"
        do "barbar"
    spec
        do replace "foo" "bar" "bar"
        do "bar"
    spec
        do replace "foo" "bar" "baz"
        do "baz"
    spec
        do replace "foo" "bar" "fook"
        do "bark"
    spec
        do replace "foo" "bar" "fof"
        do "fof"
    spec
        do replace "foo" "bar" "ffoo"
        do "fbar"
    spec
        do replace "foo" "bar" "ffofoo"
        do "ffobar"
    spec
        do replace "foo" "bar" "barfoobar"
        do "barbarbar"
    -- -- are we really good ?
    spec
        do take 6 (replace "foo" "bar" $ cycle "ffofoo")
        do "ffobar"