Re: More Finaliser Trouble
Ashley Yakeley <[email protected]>
| Newsgroups | gmane.comp.lang.haskell.ffi |
|---|---|
| Organization | Myself |
| Message-ID | <[email protected]> |
In article <[email protected]>, Fergus Henderson <[email protected]> wrote: > > Should there perhaps be something like ... > > > > newForeignPtrWithUserData :: Ptr a -> Ptr b -> FunPtr (Ptr a -> Ptr b -> IO > > ()) -> IO (ForeignPtr a) > > > > ... where the second argument is a "userData" pointer that gets passed on > > to the finalizer? > > IMHO yes! Well now what if you want to pass two extra pointers? It's true you could "glue" them together, but equally, you can glue together the two pointers passed to newForeignPtrWithUserData. Bear in mind that your newForeignPtrWithUserData, "Ptr a" and "Ptr b" are effectively interchangeable. You have one object, a ForeignPtr, that holds two pointers. When the ForeignPtr gets finalised, it passes both pointers to its finaliser function (assuming it has exactly one). There really isn't a lot of difference between the two of them when there's only one finaliser. -- Ashley Yakeley, Seattle WA