gistfile1.hs

{-# LANGUAGE TemplateHaskell, OverloadedStrings #-}
import Data.MessagePack
import qualified Data.ByteString.Lazy.Char8 as L
data OauthData = OauthData { key :: L.ByteString,
                             secret :: L.ByteString }
                 deriving(Show)
data Fake = Fake L.ByteString
            deriving(Show)

deriveObject True ''OauthData
deriveObject True ''Fake

main = do
  let l = pack $ OauthData "hi" "there"
  print l
  print $ (tryUnpack l :: Either String OauthData)