wai-app-static/Util.hs · typeable/wai

git.iko.soy/typeable/wai

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1{-# LANGUAGE OverloadedStrings #-}

2module Util

3 ( relativeDirFromPieces

4 , defaultMkRedirect

5 , replace

6 , remove

7 ) where

9import WaiAppStatic.Types

10import qualified Data.Text as T

11import Data.ByteString (ByteString)

12import qualified Data.ByteString.Char8 as S8

13import qualified Data.Text.Encoding as TE

15-- alist helper functions

16replace :: Eq a => a -> b -> [(a, b)] -> [(a, b)]

17replace k v [] = [(k,v)]

18replace k v (x:xs) | fst x == k = (k,v):xs

19 | otherwise = x:replace k v xs

21remove :: Eq a => a -> [(a, b)] -> [(a, b)]

22remove _ [] = []

23remove k (x:xs) | fst x == k = xs

24 | otherwise = x:remove k xs

26-- | Turn a list of pieces into a relative path to the root folder.

27relativeDirFromPieces :: Pieces -> T.Text

28relativeDirFromPieces pieces = T.concat $ map (const "../") (drop 1 pieces) -- last piece is not a dir

30-- | Construct redirects with relative paths.

31defaultMkRedirect :: Pieces -> ByteString -> S8.ByteString

32defaultMkRedirect pieces newPath

33 | S8.null newPath || S8.null relDir ||

34 S8.last relDir /= '/' || S8.head newPath /= '/' =

35 relDir `S8.append` newPath

36 | otherwise = relDir `S8.append` S8.tail newPath

37 where

38 relDir = TE.encodeUtf8 (relativeDirFromPieces pieces)