again: nullForeignPtr

[Alastair Reid]

> the discussion on ForeignPtrs without finalizers didn't come to a
> conclusion. I specifically need the nullForeignPtr which was easy enough
> with the FFI of GHC 5.04:
> [...]
> do I have to create a dummy C function?

Yes, create a dummy C function.
(Actually, you could use 'free' since it does nothing if passed NULL.)

--
Alastair

ps Personally, I would use

  Maybe (ForeignPtr a)

in the places where you are currently using a ForeignPtr which could be null 
with 'Just x' being used only when x is not null.

I haven't tried exactly this but I have lots of experience using  Maybe (Ptr 
a) in this way and it works great: Haskell's type system catches errors that 
would be runtime errors in C.