
  copied from ndmitchell / shake / src / Development / Shake / Internal / FileName.hs commit 8a96542
module General.FileName(
  FileName,
  fileNameFromString, fileNameFromByteString,
  fileNameToString, fileNameToByteString,
  byteStringToFileName
  ) where

import qualified Data.ByteString.Char8 as BS
import qualified Data.ByteString.UTF8 as UTF8
import Development.Shake.Classes
import qualified System.FilePath as Native
import System.Info.Extra
import Data.List

---------------------------------------------------------------------
-- FileName newtype

  | The hash of the filename , and the UTF8 ByteString
data FileName = FileName Int !BS.ByteString
    deriving Eq

instance NFData FileName where
  rnf FileName{} = ()

instance Ord FileName where
  compare (FileName _ a) (FileName _ b) = compare a b

instance Hashable FileName where
    hashWithSalt _ = hash
    hash (FileName x _) = x

instance Show FileName where
  show = fileNameToString

fileNameToString :: FileName -> FilePath
fileNameToString = UTF8.toString . fileNameToByteString

fileNameToByteString :: FileName -> BS.ByteString
fileNameToByteString (FileName _ x) = x

fileNameFromString :: FilePath -> FileName
fileNameFromString = fileNameFromByteString . UTF8.fromString

fileNameFromByteString :: BS.ByteString -> FileName
fileNameFromByteString = byteStringToFileName . filepathNormalise

-- don't normalise
byteStringToFileName :: BS.ByteString -> FileName
byteStringToFileName x = FileName (hash x) x

---------------------------------------------------------------------
  NORMALISATION

-- | Equivalent to @toStandard . normaliseEx@ from "Development.Shake.FilePath".
filepathNormalise :: BS.ByteString -> BS.ByteString
filepathNormalise xs
    | isWindows, Just (a,xs) <- BS.uncons xs, sep a, Just (b,_) <- BS.uncons xs, sep b = '/' `BS.cons` f xs
    | otherwise = f xs
  where
    sep = Native.isPathSeparator
    f o = deslash o $ BS.concat $ (slash:) $ intersperse slash $ reverse $ (BS.empty:) $ g 0 $ reverse $ split o

    deslash o x
      | x == slash = case (pre,pos) of
                       (True,True) -> slash
                       (True,False) -> BS.pack "/."
                       (False,True) -> BS.pack "./"
                       (False,False) -> dot
      | otherwise = (if pre then id else BS.tail) $ (if pos then id else BS.init) x
      where pre = not (BS.null o) && sep (BS.head o)
            pos = not (BS.null o) && sep (BS.last o)

    g i [] = replicate i dotDot
    g i (x:xs) | BS.null x = g i xs
    g i (x:xs) | x == dotDot = g (i+1) xs
    g i (x:xs) | x == dot = g i xs
    g 0 (x:xs) = x : g 0 xs
    g i (_:xs) = g (i-1) xs -- equivalent to eliminating ../x

    split = BS.splitWith sep

dotDot = BS.pack ".."
dot = BS.singleton '.'
slash = BS.singleton '/'

-------------------------------------------------------------------
 FileName newtype
 don't normalise
-------------------------------------------------------------------
 | Equivalent to @toStandard . normaliseEx@ from "Development.Shake.FilePath".
 equivalent to eliminating ../x

  copied from ndmitchell / shake / src / Development / Shake / Internal / FileName.hs commit 8a96542
module General.FileName(
  FileName,
  fileNameFromString, fileNameFromByteString,
  fileNameToString, fileNameToByteString,
  byteStringToFileName
  ) where

import qualified Data.ByteString.Char8 as BS
import qualified Data.ByteString.UTF8 as UTF8
import Development.Shake.Classes
import qualified System.FilePath as Native
import System.Info.Extra
import Data.List


  | The hash of the filename , and the UTF8 ByteString
data FileName = FileName Int !BS.ByteString
    deriving Eq

instance NFData FileName where
  rnf FileName{} = ()

instance Ord FileName where
  compare (FileName _ a) (FileName _ b) = compare a b

instance Hashable FileName where
    hashWithSalt _ = hash
    hash (FileName x _) = x

instance Show FileName where
  show = fileNameToString

fileNameToString :: FileName -> FilePath
fileNameToString = UTF8.toString . fileNameToByteString

fileNameToByteString :: FileName -> BS.ByteString
fileNameToByteString (FileName _ x) = x

fileNameFromString :: FilePath -> FileName
fileNameFromString = fileNameFromByteString . UTF8.fromString

fileNameFromByteString :: BS.ByteString -> FileName
fileNameFromByteString = byteStringToFileName . filepathNormalise

byteStringToFileName :: BS.ByteString -> FileName
byteStringToFileName x = FileName (hash x) x

  NORMALISATION

filepathNormalise :: BS.ByteString -> BS.ByteString
filepathNormalise xs
    | isWindows, Just (a,xs) <- BS.uncons xs, sep a, Just (b,_) <- BS.uncons xs, sep b = '/' `BS.cons` f xs
    | otherwise = f xs
  where
    sep = Native.isPathSeparator
    f o = deslash o $ BS.concat $ (slash:) $ intersperse slash $ reverse $ (BS.empty:) $ g 0 $ reverse $ split o

    deslash o x
      | x == slash = case (pre,pos) of
                       (True,True) -> slash
                       (True,False) -> BS.pack "/."
                       (False,True) -> BS.pack "./"
                       (False,False) -> dot
      | otherwise = (if pre then id else BS.tail) $ (if pos then id else BS.init) x
      where pre = not (BS.null o) && sep (BS.head o)
            pos = not (BS.null o) && sep (BS.last o)

    g i [] = replicate i dotDot
    g i (x:xs) | BS.null x = g i xs
    g i (x:xs) | x == dotDot = g (i+1) xs
    g i (x:xs) | x == dot = g i xs
    g 0 (x:xs) = x : g 0 xs

    split = BS.splitWith sep

dotDot = BS.pack ".."
dot = BS.singleton '.'
slash = BS.singleton '/'
