{-# LANGUAGE CPP #-}
{-# OPTIONS_HADDOCK hide #-}
--------------------------------------------------------------------------------
-- |
-- Module      :  Graphics.Rendering.OpenGL.GL.Exception
-- Copyright   :  (c) Sven Panne 2002-2019
-- License     :  BSD3
--
-- Maintainer  :  Sven Panne <svenpanne@gmail.com>
-- Stability   :  stable
-- Portability :  portable
--
-- This is a purely internal module to compensate for differences between
-- Haskell implementations.
--
--------------------------------------------------------------------------------

module Graphics.Rendering.OpenGL.GL.Exception (
   bracket, bracket_, unsafeBracket_, finallyRet
) where

import Data.IORef ( newIORef, readIORef, writeIORef )

#ifdef __NHC__
import qualified IO ( bracket, bracket_ )

{-# INLINE bracket #-}
bracket  :: IO a -> (a -> IO b) -> (a -> IO c) -> IO c
bracket = IO.bracket

{-# INLINE bracket_ #-}
bracket_ :: IO a -> IO b -> IO c -> IO c
bracket_ before = IO.bracket_ before . const

finally :: IO a -> IO b -> IO a
finally = flip . bracket_ . return $ undefined
#else
import Control.Exception ( bracket, bracket_, finally )
#endif

{-# INLINE unsafeBracket_ #-}
unsafeBracket_ :: IO a -> IO b -> IO c -> IO c
unsafeBracket_ :: forall a b c. IO a -> IO b -> IO c -> IO c
unsafeBracket_ IO a
before IO b
after IO c
thing = do
   a
_ <- IO a
before
   c
r <- IO c
thing
   b
_ <- IO b
after
   c -> IO c
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return c
r

{-# INLINE finallyRet #-}
finallyRet :: IO a -> IO b -> IO (a, b)
IO a
a finallyRet :: forall a b. IO a -> IO b -> IO (a, b)
`finallyRet` IO b
sequel = do
   IORef b
r2Ref <- b -> IO (IORef b)
forall a. a -> IO (IORef a)
newIORef b
forall a. HasCallStack => a
undefined
   a
r1 <- IO a
a IO a -> IO () -> IO a
forall a b. IO a -> IO b -> IO a
`finally` (IO b
sequel IO b -> (b -> IO ()) -> IO ()
forall a b. IO a -> (a -> IO b) -> IO b
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= IORef b -> b -> IO ()
forall a. IORef a -> a -> IO ()
writeIORef IORef b
r2Ref)
   b
r2 <- IORef b -> IO b
forall a. IORef a -> IO a
readIORef IORef b
r2Ref
   (a, b) -> IO (a, b)
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (a
r1, b
r2)