Queue.hsc

--------------------------------------------------------------------------------
-- |
-- Module    : Sound.ALSA.Sequencer.Marshal.Queue
-- Copyright : (c) Henning Thielemann, 2010
--             (c) Iavor S. Diatchki, 2007
-- License   : BSD3
--
-- Maintainer: Henning Thielemann
-- Stability : provisional
--
-- PRIVATE MODULE.
--
-- Here we have the various types used by the library,
-- and how they are imported\/exported to C.
--
-- NOTE: In the translations bellow we make the following assumptions
-- about the sizes of C types.
-- CChar  = 8 bits
-- CShort = 16 bit
-- CInt   = 32 bits
--------------------------------------------------------------------------------

module Sound.ALSA.Sequencer.Marshal.Queue where

#include <alsa/asoundlib.h>
import qualified Sound.ALSA.Sequencer.Utility as U
import Foreign.C.Types (CInt, )
import Foreign.Storable (Storable, )
import Data.Word (Word8, )




-- | The type of queue identifiers.
newtype T = Cons Word8 deriving (Eq, Ord, Storable)

instance Show T where
   showsPrec prec (Cons x) =
      U.showsRecord prec "Queue" [U.showsField x]

imp :: CInt -> T
imp x = Cons (fromIntegral x)

exp :: T -> CInt
exp (Cons x) = fromIntegral x

#{enum T, Cons
 , direct = SND_SEQ_QUEUE_DIRECT
 }