encoding/Data/Encoding/KOI8R.hs
Henning Guenther 496761301f Initial commit
darcs-hash:20070802003505-a4fee-97432a586ed2453061ef246d1e7a81fec35d1bac
2007-08-01 17:35:05 -07:00

60 lines
2.2 KiB
Haskell

module Data.Encoding.KOI8R
(KOI8R(..)) where
import Control.Exception (throwDyn)
import Data.Array.Unboxed
import Data.ByteString.Base (c2w,w2c)
import qualified Data.ByteString.Lazy as Lazy
import Data.Map hiding (map,(!))
import Data.Word
import Prelude hiding (lookup)
import Data.Encoding.Base
data KOI8R = KOI8R
koi8rArr :: UArray Word8 Char
koi8rArr = listArray (128,255) koi8rList
koi8rMap :: Map Char Word8
koi8rMap = fromList (zip koi8rList [0..])
koi8rList :: [Char]
koi8rList =
['\x2500','\x2502','\x250c','\x2510','\x2514','\x2518','\x251c','\x2524'
,'\x252c','\x2534','\x253c','\x2580','\x2584','\x2588','\x258c','\x2590'
,'\x2591','\x2592','\x2593','\x2320','\x25a0','\x2219','\x221a','\x2248'
,'\x2264','\x2265','\x00a0','\x2321','\x00b0','\x00b2','\x00b7','\x00f7'
,'\x2550','\x2551','\x2552','\x0451','\x2553','\x2554','\x2555','\x2556'
,'\x2557','\x2558','\x2559','\x255a','\x255b','\x255c','\x255d','\x255e'
,'\x255f','\x2560','\x2561','\x0401','\x2562','\x2563','\x2564','\x2565'
,'\x2566','\x2567','\x2568','\x2569','\x256a','\x256b','\x256c','\x00a9'
,'\x044e','\x0430','\x0431','\x0446','\x0434','\x0435','\x0444','\x0433'
,'\x0445','\x0438','\x0439','\x043a','\x043b','\x043c','\x043d','\x043e'
,'\x043f','\x044f','\x0440','\x0441','\x0442','\x0443','\x0436','\x0432'
,'\x044c','\x044b','\x0437','\x0448','\x044d','\x0449','\x0447','\x044a'
,'\x042e','\x0410','\x0411','\x0426','\x0414','\x0415','\x0424','\x0413'
,'\x0425','\x0418','\x0419','\x041a','\x041b','\x041c','\x041d','\x041e'
,'\x041f','\x042f','\x0420','\x0421','\x0422','\x0423','\x0416','\x0412'
,'\x042c','\x042b','\x0417','\x0428','\x042d','\x0429','\x0427','\x042a']
koi8rDecode :: Word8 -> Char
koi8rDecode ch
| ch < 128 = w2c ch
| otherwise = koi8rArr!ch
koi8rEncode :: Char -> Word8
koi8rEncode ch
| ch < '\128' = c2w ch
| otherwise = case lookup ch koi8rMap of
Just w -> w
Nothing -> throwDyn (HasNoRepresentation ch)
instance Encoding KOI8R where
encode _ = encodeSinglebyte koi8rEncode
encodeLazy _ = encodeSinglebyteLazy koi8rEncode
encodable _ c = (c < '\128') || (member c koi8rMap)
decode _ = decodeSinglebyte koi8rDecode
decodeLazy _ str = concatMap (decodeSinglebyte koi8rDecode) (Lazy.toChunks str)
decodable _ = const True