Writable class

[EsounD.git] / Sound / EsounD / Internals.hs

diff --git a/Sound/EsounD/Internals.hs b/Sound/EsounD/Internals.hs
index f75f99a0dc1770777e9aa196505058a1854539f3..4f57a3b07e694772fc507bd2590041311411e73b 100644 (file)
--- a/Sound/EsounD/Internals.hs
+++ b/Sound/EsounD/Internals.hs
@@ -1,3 +1,7 @@
+{-# LANGUAGE
+    EmptyDataDecls
+  , UnicodeSyntax
+  #-}
 module Sound.EsounD.Internals
     ( Frame(..)
 
@@ -10,17 +14,17 @@ module Sound.EsounD.Internals
     , withCStrOrNull
     )
     where
-
 import Bindings.EsounD
 import Data.Int
 import Foreign.C.String
 import Foreign.C.Types
 import Foreign.Ptr
+import Foreign.Storable
 import System.IO
 import System.Posix.IO
 import System.Posix.Types
 
-class Frame fr where
+class Storable fr ⇒ Frame fr where
     frameFmt ∷ fr → C'esd_format_t
 
 instance Frame Int8 where
@@ -40,16 +44,15 @@ data Stereo
 instance Channels Stereo where
     channelFmt _ = c'ESD_STEREO
 
-
-wrapSocket :: String -> CInt → IO Handle
+wrapSocket ∷ String → CInt → IO Handle
 wrapSocket e (-1) = fail e
 wrapSocket _ fd   = fdToHandle (Fd fd)
 
-closeSocket :: Handle → IO ()
+closeSocket ∷ Handle → IO ()
 closeSocket h = do (Fd fd) ← handleToFd h
                    _       ← c'esd_close (fromIntegral fd)
                    return ()
 
-withCStrOrNull :: Maybe String → (CString → IO a) → IO a
+withCStrOrNull ∷ Maybe String → (CString → IO a) → IO a
 withCStrOrNull Nothing  f = f nullPtr
 withCStrOrNull (Just s) f = withCString s f