module Data.Machines.Encoding.Text
 ( decodeLatin1
 , encodeUtf8, decodeUtf8
 ) where

import           Data.ByteString (ByteString)
import           Data.Machine
import           Data.Text (Text)
import qualified Data.Text.Encoding as TE

{- | Convert a stream of ByteStrings to a stream of Text
 -   by transorming the bytes from the Latin1 encoding.
 -}
decodeLatin1 :: Process ByteString Text
decodeLatin1 = auto TE.decodeLatin1
{-# INLINE decodeLatin1 #-}

{- | Convert a stream of Text to a stream of ByteStrings
 -   by transorming the symboles to the UTF-8 encoding.
 -}
encodeUtf8 :: Process Text ByteString
encodeUtf8 = auto TE.encodeUtf8
{-# LANGUAGE encodeUtf8 #-}

{- | Convert a stream of ByteStrings to a stream of Text
 -   by transorming the bytes from the UTF-8 encoding.
 -}
decodeUtf8 :: Process ByteString Text
decodeUtf8 = auto . Mealy $ runDecode . TE.streamDecodeUtf8
  where
    runDecode :: TE.Decoding -> (Text, Mealy ByteString Text)
    runDecode (TE.Some r _ c) = (r, Mealy $ runDecode . c)
    {-# INLINE runDecode #-}
{-# INLINE decodeUtf8 #-}