diff options
Diffstat (limited to 'src/Erebos/Util.hs')
| -rw-r--r-- | src/Erebos/Util.hs | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/src/Erebos/Util.hs b/src/Erebos/Util.hs index ffca9c7..0381c3e 100644 --- a/src/Erebos/Util.hs +++ b/src/Erebos/Util.hs @@ -1,5 +1,14 @@ module Erebos.Util where +import Control.Monad + +import Data.ByteArray (ByteArray, ByteArrayAccess) +import Data.ByteArray qualified as BA +import Data.ByteString (ByteString) +import Data.ByteString qualified as B +import Data.Char + + uniq :: Eq a => [a] -> [a] uniq (x:y:xs) | x == y = uniq (x:xs) | otherwise = x : uniq (y:xs) @@ -35,3 +44,24 @@ intersectsSorted (x:xs) (y:ys) | x < y = intersectsSorted xs (y:ys) | x > y = intersectsSorted (x:xs) ys | otherwise = True intersectsSorted _ _ = False + + +showHex :: ByteArrayAccess ba => ba -> ByteString +showHex = B.concat . map showHexByte . BA.unpack + where showHexChar x | x < 10 = x + o '0' + | otherwise = x + o 'a' - 10 + showHexByte x = B.pack [ showHexChar (x `div` 16), showHexChar (x `mod` 16) ] + o = fromIntegral . ord + +readHex :: ByteArray ba => ByteString -> Maybe ba +readHex = return . BA.concat <=< readHex' + where readHex' bs | B.null bs = Just [] + readHex' bs = do (bx, bs') <- B.uncons bs + (by, bs'') <- B.uncons bs' + x <- hexDigit bx + y <- hexDigit by + (B.singleton (x * 16 + y) :) <$> readHex' bs'' + hexDigit x | x >= o '0' && x <= o '9' = Just $ x - o '0' + | x >= o 'a' && x <= o 'z' = Just $ x - o 'a' + 10 + | otherwise = Nothing + o = fromIntegral . ord |