{-# LANGUAGE CPP,TemplateHaskell,DeriveDataTypeable #-}
{- | This module implements Windows Codepage number 1251 which encodes languages that use the cyrillic alphabet.
     See <http://en.wikipedia.org/wiki/CP1251> for more information.
module Data.Encoding.CP1251
	(CP1251(..)) where

import Data.Array ((!),Array)
import Data.Word (Word8)
import Data.ByteString (all)
import Data.Map (Map,lookup,member)
import Data.Encoding.Base
import Prelude hiding (lookup,all)
import Control.Exception (throwDyn)
import Data.Typeable

data CP1251 = CP1251 deriving (Eq,Show,Typeable)

instance Encoding CP1251 where
	encode _ = encodeSinglebyte (\c -> case lookup c encodeMap of
		Just v -> v
		Nothing -> throwDyn (HasNoRepresentation c))
	encodable _ c = member c encodeMap
	decode _ = decodeSinglebyte (decodeArr!)
	decodable _ = all (\w -> decodeArr!w /= '\xFFFD')

decodeArr :: Array Word8 Char
#ifndef __HADDOCK__
decodeArr = $(decodingArray "CP1251.TXT")

encodeMap :: Map Char Word8
#ifndef __HADDOCK__
encodeMap =  $(encodingMap "CP1251.TXT")