92 lines
2.9 KiB
Haskell
92 lines
2.9 KiB
Haskell
-- module Encoding.Base62
|
|
-- ( enc62
|
|
-- , dec62
|
|
-- ) where
|
|
|
|
|
|
-- import qualified Data.Word.Base62 as B62
|
|
-- import Text.Read (readMaybe)
|
|
-- import Data.Maybe (fromMaybe)
|
|
-- import Data.ByteString.UTF8 as BSU -- from utf8-string
|
|
-- import qualified Data.Bytes as Bytes
|
|
-- import Data.Bytes.Text.Latin1 as Latin1
|
|
-- import qualified Data.ByteString.Char8 as C
|
|
-- import qualified Data.Text as T
|
|
-- import qualified Data.Text.Encoding as T
|
|
-- -- import qualified Data.Text.IO as T
|
|
|
|
|
|
-- dec62 :: String -> String
|
|
-- dec62 input =
|
|
-- let decoded = B62.decode128 (Bytes.fromByteString (BSU.fromString input))
|
|
-- in fromMaybe "Error decoding Base62.\n" (show <$> decoded)
|
|
-- let decoded = BC.unpack $ B62.decode128
|
|
|
|
-- stringToInt :: String -> Maybe Integer
|
|
-- stringToInt = readMaybe
|
|
|
|
-- enc62 :: String -> String
|
|
-- enc62 input =
|
|
-- let intValue = fromMaybe (error "Error: Unable to convert input string to integer") (stringToInt input)
|
|
-- encoded = B62.encode64 (fromIntegral intValue)
|
|
-- encodedText = T.decodeUtf8 (BSU.fromString (Latin1.toString (Bytes.fromByteArray encoded)))
|
|
-- in T.unpack encodedText
|
|
|
|
module Encoding.Base62
|
|
( enc62
|
|
, dec62
|
|
) where
|
|
|
|
import qualified Data.ByteString.Char8 as BC
|
|
import qualified Data.ByteString as BS
|
|
import Data.ByteString.Internal (c2w, w2c)
|
|
import Data.List (elemIndex)
|
|
import Data.Maybe (fromMaybe)
|
|
import Numeric (showIntAtBase)
|
|
import Data.Char (intToDigit)
|
|
import qualified Data.Text as T
|
|
import qualified Data.Text.Encoding as T
|
|
import System.IO.Unsafe (unsafePerformIO)
|
|
import qualified Data.List as List
|
|
|
|
base62Chars :: String
|
|
base62Chars = ['0'..'9'] ++ ['A'..'Z'] ++ ['a'..'z']
|
|
|
|
-- Convert a ByteString to an Integer
|
|
byteStringToInteger :: BS.ByteString -> Integer
|
|
byteStringToInteger = BC.foldl' (\acc w -> acc * 256 + fromIntegral (c2w w)) 0
|
|
|
|
-- Convert an Integer to a ByteString
|
|
integerToByteString :: Integer -> BS.ByteString
|
|
integerToByteString 0 = BC.singleton (w2c 0)
|
|
integerToByteString i = BC.reverse $ BC.unfoldr step i
|
|
where
|
|
step 0 = Nothing
|
|
step x = Just (w2c (fromIntegral (x `mod` 256)), x `div` 256)
|
|
|
|
-- Encode an Integer to a Base62 ByteString
|
|
encodeBase62 :: Integer -> BS.ByteString
|
|
encodeBase62 0 = BC.singleton (base62Chars !! 0)
|
|
encodeBase62 n = BC.reverse $ BC.unfoldr step n
|
|
where
|
|
step 0 = Nothing
|
|
step x = let (q, r) = x `divMod` 62
|
|
in Just (base62Chars !! fromIntegral r, q)
|
|
|
|
decodeBase62 :: BS.ByteString -> Integer
|
|
decodeBase62 = BC.foldl' (\acc w -> acc * 62 + fromIntegral (fromMaybe 0 (elemIndex w base62Chars))) 0
|
|
where
|
|
elemIndex :: Char -> String -> Maybe Int
|
|
elemIndex c str = List.findIndex (== c) str
|
|
|
|
enc62 :: BC.ByteString -> BC.ByteString
|
|
enc62 input =
|
|
let intValue = byteStringToInteger input
|
|
in encodeBase62 intValue
|
|
|
|
dec62 :: BC.ByteString -> BC.ByteString
|
|
dec62 input =
|
|
let decoded = decodeBase62 input
|
|
in integerToByteString decoded
|
|
|