[project @ 2005-01-27 10:45:47 by simonpj]

[ghc-base.git] / Foreign / Ptr.hs

diff --git a/Foreign/Ptr.hs b/Foreign/Ptr.hs
index ca6ed10..ad20da4 100644 (file)
--- a/Foreign/Ptr.hs
+++ b/Foreign/Ptr.hs
@@ -1,35 +1,34 @@
-{-# OPTIONS -fno-implicit-prelude #-}
+{-# OPTIONS_GHC -fno-implicit-prelude #-}
 -----------------------------------------------------------------------------
--- 
+-- |
 -- Module      :  Foreign.Ptr
 -- Copyright   :  (c) The FFI task force 2001
--- License     :  BSD-style (see the file libraries/core/LICENSE)
+-- License     :  BSD-style (see the file libraries/base/LICENSE)
 -- 
 -- Maintainer  :  ffi@haskell.org
 -- Stability   :  provisional
 -- Portability :  portable
 --
--- $Id: Ptr.hs,v 1.2 2001/07/03 11:37:50 simonmar Exp $
---
--- Pointer types.
+-- This module provides typed pointers to foreign data.  It is part
+-- of the Foreign Function Interface (FFI) and will normally be
+-- imported via the "Foreign" module.
 --
 -----------------------------------------------------------------------------
 
 module Foreign.Ptr (
-    --------------------------------------------------------------------
-    -- Data pointers.
+
+    -- * Data pointers
     
-    Ptr(..),      -- data Ptr a
+    Ptr,      -- data Ptr a
     nullPtr,      -- :: Ptr a
     castPtr,      -- :: Ptr a -> Ptr b
     plusPtr,      -- :: Ptr a -> Int -> Ptr b
     alignPtr,     -- :: Ptr a -> Int -> Ptr a
     minusPtr,     -- :: Ptr a -> Ptr b -> Int
     
-    --------------------------------------------------------------------
-    -- Function pointers.
+    -- * Function pointers
     
-    FunPtr(..),      -- data FunPtr a
+    FunPtr,      -- data FunPtr a
     nullFunPtr,      -- :: FunPtr a
     castFunPtr,      -- :: FunPtr a -> FunPtr b
     castFunPtrToPtr, -- :: FunPtr a -> Ptr b
@@ -40,16 +39,59 @@ module Foreign.Ptr (
 
  ) where
 
-import Data.Dynamic
-
 #ifdef __GLASGOW_HASKELL__
 import GHC.Ptr
 import GHC.IOBase
-import GHC.Err
+import GHC.Base
+import GHC.Num
+import GHC.List
+import GHC.Show
+import Numeric
 #endif
 
-foreign import "freeHaskellFunctionPtr" unsafe
-    freeHaskellFunPtr :: FunPtr a -> IO ()
+#ifdef __NHC__
+import NHC.FFI
+  ( Ptr
+  , nullPtr
+  , castPtr
+  , plusPtr
+  , alignPtr
+  , minusPtr
+  , FunPtr
+  , nullFunPtr
+  , castFunPtr
+  , castFunPtrToPtr
+  , castPtrToFunPtr
+  , freeHaskellFunPtr
+  )
+#endif
+
+#ifdef __HUGS__
+import Hugs.Ptr
+#endif
 
-#include "Dynamic.h"
-INSTANCE_TYPEABLE1(Ptr,ptrTc,"Ptr")
+#ifdef __GLASGOW_HASKELL__
+#include "MachDeps.h"
+
+#if (WORD_SIZE_IN_BITS == 32 || WORD_SIZE_IN_BITS == 64)
+instance Show (Ptr a) where
+   showsPrec p (Ptr a) rs = pad_out (showHex (word2Integer(int2Word#(addr2Int# a))) "") rs
+     where
+        -- want 0s prefixed to pad it out to a fixed length.
+       pad_out ls rs = 
+         '0':'x':(replicate (2*SIZEOF_HSPTR - length ls) '0') ++ ls ++ rs
+       -- word2Integer :: Word# -> Integer (stolen from Word.lhs)
+       word2Integer w = case word2Integer# w of
+                       (# s, d #) -> J# s d
+
+instance Show (FunPtr a) where
+   showsPrec p = showsPrec p . castFunPtrToPtr
+#endif
+
+-- | Release the storage associated with the given 'FunPtr', which
+-- must have been obtained from a wrapper stub.  This should be called
+-- whenever the return value from a foreign import wrapper function is
+-- no longer required; otherwise, the storage it uses will leak.
+foreign import ccall unsafe "freeHaskellFunctionPtr"
+    freeHaskellFunPtr :: FunPtr a -> IO ()
+#endif