acid-state-tls-0.9.0: examples/RemoteCommon.hs

{-# LANGUAGE TemplateHaskell, DeriveDataTypeable, TypeFamilies #-}
module RemoteCommon where

import Data.Acid

import Control.Monad.State
import Control.Monad.Reader
import System.Environment
import System.IO
import Data.SafeCopy

import Data.Typeable

------------------------------------------------------
-- The Haskell structure that we want to encapsulate

data StressState = StressState !Int
    deriving (Typeable)

$(deriveSafeCopy 0 'base ''StressState)

------------------------------------------------------
-- The transaction we will execute over the state.

pokeState :: Update StressState ()
pokeState = do StressState i <- get
               put (StressState (i+1))

queryState :: Query StressState Int
queryState = do StressState i <- ask
                return i

clearState :: Update StressState ()
clearState = put $ StressState 0

$(makeAcidic ''StressState ['pokeState, 'queryState, 'clearState])