-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Weak pointer extas
--   
--   Better weak pointer support for IORefs and ForeignPtrs.
@package weak
@version 0


module System.Mem.Weak.IORef

-- | Make an arbitrary <a>Weak</a> reference from a <a>IORef</a>.
--   
--   Provides a more general API than the crippled one offered by
--   <a>mkWeakIORef</a> to match the power of <a>mkWeak</a>.
mkWeakIORef' :: IORef k -> v -> Maybe (IO ()) -> IO (Weak v)

-- | Functions like <a>mkWeakPtr</a> but for <a>IORef</a>s.
--   
--   Make an arbitrary <a>Weak</a> reference from an <a>IORef</a> and an
--   optional finalizer.
--   
--   A specialised version of <a>mkWeakIORef'</a> where the key and value
--   are the same.
mkWeakIORefPtr :: IORef k -> Maybe (IO ()) -> IO (Weak (IORef k))

-- | A specialised version of <a>mkWeakIORef'</a> where the value is
--   actually a pair of the key and value passed to <a>mkWeakIORefPair</a>:
--   
--   <pre>
--   <a>mkWeakIORefPair</a> key val finalizer ≡ <a>mkWeakIORef'</a> key (key,val) finalizer
--   </pre>
--   
--   The advantage of this is that the key can be retrieved by
--   <a>deRefWeak</a> in addition to the value.
mkWeakIORefPair :: IORef k -> v -> Maybe (IO ()) -> IO (Weak (IORef k, v))


module System.Mem.Weak.ForeignPtr

-- | Make a <a>Weak</a> reference from a <a>ForeignPtr</a>. This attaches
--   to the <a>IORef</a> down inside of the <a>ForeignPtr</a> that holds
--   onto the finalizers. This is safer than attaching to the
--   <a>ForeignPtr</a> itself.
--   
--   However: this does not work with <a>PlainPtr</a> or
--   <a>FinalPtr</a>-based <a>ForeignPtr</a>s, so make sure you know how
--   you built your <a>ForeignPtr</a>.
mkWeakForeignPtr :: ForeignPtr k -> v -> Maybe (IO ()) -> IO (Weak v)

-- | Functions like <a>mkWeakPtr</a> but for <a>ForeignPtr</a>s.
--   
--   A specialised version of <a>mkWeakForeignPtr</a>, where the key and
--   the value are the same object:
--   
--   <pre>
--   <a>mkWeakForeignPtrPtr</a> key finalizer = <a>mkWeakForeignPtr</a> key key finalizer
--   </pre>
mkWeakForeignPtrPtr :: ForeignPtr a -> Maybe (IO ()) -> IO (Weak (ForeignPtr a))

-- | Functions like <a>mkWeakPair</a> but for <a>ForeignPtr</a>s.
--   
--   A specialised version of <a>mkWeakForeignPtr</a> where the value is
--   actually a pair of the key and value passed to
--   <a>mkWeakForeignPtrPair</a>: <tt> <a>mkWeakForeignPtrPair</a> key val
--   finalizer ≡ <a>mkWeakForeignPtr</a> key (key,val) finalizer </tt> The
--   advantage of this is that the key can be retrieved by <a>deRefWeak</a>
--   in addition to the value.
mkWeakForeignPtrPair :: ForeignPtr k -> v -> Maybe (IO ()) -> IO (Weak (ForeignPtr k, v))