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module Development.Shake.ByteString(parseMakefile, normalise, linesCR) where
import qualified Data.ByteString.Char8 as BS
import qualified System.FilePath as Native
import General.Base
import Data.List
endsSlash :: BS.ByteString -> Bool
endsSlash = BS.isSuffixOf (BS.singleton '\\')
parseMakefile :: BS.ByteString -> [(BS.ByteString, [BS.ByteString])]
parseMakefile = concatMap f . join . linesCR
where
join xs = case span endsSlash xs of
([], []) -> []
(xs, []) -> [BS.unwords $ map BS.init xs]
([], y:ys) -> y : join ys
(xs, y:ys) -> BS.unwords (map BS.init xs ++ [y]) : join ys
f x = [(a, BS.words $ BS.drop 1 b) | a <- BS.words a]
where (a,b) = BS.break (== ':') $ BS.takeWhile (/= '#') x
-- | This is a hot-spot, so optimised
linesCR :: BS.ByteString -> [BS.ByteString]
linesCR x = case BS.split '\n' x of
x:xs | Just ('\r',x) <- unsnoc x -> x : map (\x -> case unsnoc x of Just ('\r',x) -> x; _ -> x) xs
xs -> xs
where
-- the ByteString unsnoc was introduced in a newer version
unsnoc x | BS.null x = Nothing
| otherwise = Just (BS.last x, BS.init x)
normalise :: BS.ByteString -> BS.ByteString
normalise 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 (x:xs) = g (i-1) xs
split xs = BS.splitWith sep xs
dotDot = BS.pack ".."
dot = BS.singleton '.'
slash = BS.singleton '/'
|
