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|
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ViewPatterns #-}
module Util (
relativeDirFromPieces,
defaultMkRedirect,
replace,
remove,
dropLastIfNull,
) where
import Data.ByteString (ByteString)
import qualified Data.ByteString.Char8 as S8
import qualified Data.Text as T
import qualified Data.Text.Encoding as TE
import WaiAppStatic.Types
-- alist helper functions
replace :: Eq a => a -> b -> [(a, b)] -> [(a, b)]
replace k v [] = [(k, v)]
replace k v (x : xs)
| fst x == k = (k, v) : xs
| otherwise = x : replace k v xs
remove :: Eq a => a -> [(a, b)] -> [(a, b)]
remove _ [] = []
remove k (x : xs)
| fst x == k = xs
| otherwise = x : remove k xs
-- | Turn a list of pieces into a relative path to the root folder.
relativeDirFromPieces :: Pieces -> T.Text
relativeDirFromPieces pieces = T.concat $ map (const "../") (drop 1 pieces) -- last piece is not a dir
-- | Construct redirects with relative paths.
defaultMkRedirect :: Pieces -> ByteString -> S8.ByteString
defaultMkRedirect pieces newPath
| S8.null newPath
|| S8.null relDir
|| S8.last relDir /= '/'
|| S8.head newPath /= '/' =
relDir `S8.append` newPath
| otherwise = relDir `S8.append` S8.tail newPath
where
relDir = TE.encodeUtf8 (relativeDirFromPieces pieces)
dropLastIfNull :: [Piece] -> [Piece]
dropLastIfNull pieces = case pieces of
[fromPiece -> ""] -> []
(a : r) -> a : dropLastIfNull r
[] -> []
|
