{-# LANGUAGE TypeFamilies #-}

-- |
-- Module     : Simulation.Aivika.RealTime.Ref.Base.Lazy
-- Copyright  : Copyright (c) 2016-2017, David Sorokin <david.sorokin@gmail.com>
-- License    : BSD3
-- Maintainer : David Sorokin <david.sorokin@gmail.com>
-- Stability  : experimental
-- Tested with: GHC 8.0.1
--
-- The 'RT' monad can be an instance of lazy 'MonadRef'.
--
module Simulation.Aivika.RealTime.Ref.Base.Lazy () where

import Data.IORef

import Control.Monad
import Control.Monad.Trans

import Simulation.Aivika.Trans.Internal.Types
import Simulation.Aivika.Trans.Ref.Base.Lazy

import Simulation.Aivika.RealTime.Internal.RT

-- | The 'RT' monad is an instance of 'MonadRef'.
instance (Monad m, MonadIO m) => MonadRef (RT m) where

  {-# SPECIALISE instance MonadRef (RT IO) #-}

  -- | A type safe wrapper for the 'IORef' reference.
  newtype Ref (RT m) a = Ref { Ref (RT m) a -> IORef a
refValue :: IORef a }

  {-# INLINE newRef #-}
  newRef :: a -> Simulation (RT m) (Ref (RT m) a)
newRef a
a =
    (Run (RT m) -> RT m (Ref (RT m) a))
-> Simulation (RT m) (Ref (RT m) a)
forall (m :: * -> *) a. (Run m -> m a) -> Simulation m a
Simulation ((Run (RT m) -> RT m (Ref (RT m) a))
 -> Simulation (RT m) (Ref (RT m) a))
-> (Run (RT m) -> RT m (Ref (RT m) a))
-> Simulation (RT m) (Ref (RT m) a)
forall a b. (a -> b) -> a -> b
$ \Run (RT m)
r ->
    do IORef a
x <- IO (IORef a) -> RT m (IORef a)
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO (IORef a) -> RT m (IORef a)) -> IO (IORef a) -> RT m (IORef a)
forall a b. (a -> b) -> a -> b
$ a -> IO (IORef a)
forall a. a -> IO (IORef a)
newIORef a
a
       Ref (RT m) a -> RT m (Ref (RT m) a)
forall (m :: * -> *) a. Monad m => a -> m a
return Ref :: forall (m :: * -> *) a. IORef a -> Ref (RT m) a
Ref { refValue :: IORef a
refValue = IORef a
x }
     
  {-# INLINE readRef #-}
  readRef :: Ref (RT m) a -> Event (RT m) a
readRef Ref (RT m) a
r = (Point (RT m) -> RT m a) -> Event (RT m) a
forall (m :: * -> *) a. (Point m -> m a) -> Event m a
Event ((Point (RT m) -> RT m a) -> Event (RT m) a)
-> (Point (RT m) -> RT m a) -> Event (RT m) a
forall a b. (a -> b) -> a -> b
$ \Point (RT m)
p ->
    IO a -> RT m a
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO a -> RT m a) -> IO a -> RT m a
forall a b. (a -> b) -> a -> b
$ IORef a -> IO a
forall a. IORef a -> IO a
readIORef (Ref (RT m) a -> IORef a
forall (m :: * -> *) a. Ref (RT m) a -> IORef a
refValue Ref (RT m) a
r)

  {-# INLINE writeRef #-}
  writeRef :: Ref (RT m) a -> a -> Event (RT m) ()
writeRef Ref (RT m) a
r a
a = (Point (RT m) -> RT m ()) -> Event (RT m) ()
forall (m :: * -> *) a. (Point m -> m a) -> Event m a
Event ((Point (RT m) -> RT m ()) -> Event (RT m) ())
-> (Point (RT m) -> RT m ()) -> Event (RT m) ()
forall a b. (a -> b) -> a -> b
$ \Point (RT m)
p -> 
    IO () -> RT m ()
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO () -> RT m ()) -> IO () -> RT m ()
forall a b. (a -> b) -> a -> b
$ IORef a -> a -> IO ()
forall a. IORef a -> a -> IO ()
writeIORef (Ref (RT m) a -> IORef a
forall (m :: * -> *) a. Ref (RT m) a -> IORef a
refValue Ref (RT m) a
r) a
a

  {-# INLINE modifyRef #-}
  modifyRef :: Ref (RT m) a -> (a -> a) -> Event (RT m) ()
modifyRef Ref (RT m) a
r a -> a
f = (Point (RT m) -> RT m ()) -> Event (RT m) ()
forall (m :: * -> *) a. (Point m -> m a) -> Event m a
Event ((Point (RT m) -> RT m ()) -> Event (RT m) ())
-> (Point (RT m) -> RT m ()) -> Event (RT m) ()
forall a b. (a -> b) -> a -> b
$ \Point (RT m)
p -> 
    do a
a <- IO a -> RT m a
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO a -> RT m a) -> IO a -> RT m a
forall a b. (a -> b) -> a -> b
$ IORef a -> IO a
forall a. IORef a -> IO a
readIORef (Ref (RT m) a -> IORef a
forall (m :: * -> *) a. Ref (RT m) a -> IORef a
refValue Ref (RT m) a
r)
       let b :: a
b = a -> a
f a
a
       IO () -> RT m ()
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO () -> RT m ()) -> IO () -> RT m ()
forall a b. (a -> b) -> a -> b
$ IORef a -> a -> IO ()
forall a. IORef a -> a -> IO ()
writeIORef (Ref (RT m) a -> IORef a
forall (m :: * -> *) a. Ref (RT m) a -> IORef a
refValue Ref (RT m) a
r) a
b

  {-# INLINE equalRef #-}
  equalRef :: Ref (RT m) a -> Ref (RT m) a -> Bool
equalRef (Ref r1) (Ref r2) = (IORef a
r1 IORef a -> IORef a -> Bool
forall a. Eq a => a -> a -> Bool
== IORef a
r2)

-- | The 'RT' monad is an instance of 'MonadRef0'.
instance MonadIO m => MonadRef0 (RT m) where

  {-# SPECIALISE instance MonadRef0 (RT IO) #-}

  {-# INLINE newRef0 #-}
  newRef0 :: a -> RT m (Ref (RT m) a)
newRef0 a
a =
    do IORef a
x <- IO (IORef a) -> RT m (IORef a)
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO (IORef a) -> RT m (IORef a)) -> IO (IORef a) -> RT m (IORef a)
forall a b. (a -> b) -> a -> b
$ a -> IO (IORef a)
forall a. a -> IO (IORef a)
newIORef a
a
       Ref (RT m) a -> RT m (Ref (RT m) a)
forall (m :: * -> *) a. Monad m => a -> m a
return Ref :: forall (m :: * -> *) a. IORef a -> Ref (RT m) a
Ref { refValue :: IORef a
refValue = IORef a
x }