[project @ 2002-11-06 10:38:16 by simonmar]

- Add a Show instance for ForeignPtr

- Fix the Eq instance for ForeignPtr to match the behaviour specified
  by the spec.  Two ForeignPtrs are equal iff their underlying Ptrs
  are equal (previously they were equal iff they were the same
  ForeignPtr).

MERGE TO STABLE

diff --git a/Foreign/ForeignPtr.hs b/Foreign/ForeignPtr.hs
index b0dd4d5..09958dc 100644 (file)
--- a/Foreign/ForeignPtr.hs
+++ b/Foreign/ForeignPtr.hs
@@ -44,6 +44,7 @@ import GHC.IOBase
 import GHC.Num
 import GHC.Ptr ( Ptr(..) )
 import GHC.Err
+import GHC.Show
 #endif
 
 #ifdef __NHC__
@@ -82,13 +83,12 @@ data ForeignPtr a
   = ForeignPtr ForeignObj#
   | MallocPtr  (MutableByteArray# RealWorld)
 
-eqForeignPtr  :: ForeignPtr a -> ForeignPtr a -> Bool
-eqForeignPtr (ForeignPtr fo1#) (ForeignPtr fo2#) = eqForeignObj# fo1# fo2#
-eqForeignPtr (MallocPtr fo1#)  (MallocPtr fo2#)  = sameMutableByteArray# fo1# fo2#
-eqForeignPtr _ _ = False
-
 instance Eq (ForeignPtr a) where 
-    p == q = eqForeignPtr p q
+    p == q  =  foreignPtrToPtr p == foreignPtrToPtr q
+
+instance Show (ForeignPtr a) where
+    showsPrec p f = showsPrec p (foreignPtrToPtr f)
+
 
 newForeignPtr :: Ptr a -> IO () -> IO (ForeignPtr a)
 -- ^Turns a plain memory reference into a foreign object