quyse/flaw

{-|
Module: Flaw.Network.MessageSocket
Description: Serializing wrapper over socket.
License: MIT
-}

{-# LANGUAGE GADTs #-}

module Flaw.Network.MessageSocket
  ( MessageSocket(..)
  , readMessageSocket
  , writeMessageSocket
  ) where

import Control.Concurrent.STM
import qualified Data.Serialize as S

import Flaw.Network

data MessageSocket i o where
  MessageSocket :: Socket s => s -> MessageSocket i o

readMessageSocket :: S.Serialize i => MessageSocket i o -> STM i
readMessageSocket (MessageSocket socket) = do
  eitherValue <- S.decode <$> readSocket socket
  return $ case eitherValue of
    Right value -> value
    Left err -> error err

writeMessageSocket :: S.Serialize o => MessageSocket i o -> o -> STM ()
writeMessageSocket (MessageSocket socket) = writeSocket socket . S.encode