On Wed, 2006-03-15 at 17:01 +0000, Brian Hulley wrote: > Simon Marlow wrote:
> > This is the way it used to be in GHC before the FFI. In the FFI we > > moved to withForeignPtr instead. IIRC, the motivation was something > > along these lines: > > > > - allowing ForeignPtr to be passed directly to a foreign function > > implies some magic that happens at the point of the foreign call > > to convert the ForeignPtr to a Ptr. > > > > - there also has to be some magic to ensure that the ForeignPtr > > couldn't be finalized until the call returns. This amounted to > > adding a touch# primitive to keep the ForeignPtr alive over the > > call. So internally the compiler was doing something like > > withForeignPtr anyway. This behaviour is quite hard to explain in > > the spec, withForeignPtr is much simpler. > > > The above two things were what I was expecting the compiler to do for me > instead of me having to manually write a wrapper function in Haskell using > withForeignPtr for each wrapper function for each foreign function... This is exactly the sort of thing that FFI tools automate. Indeed they can do this and much more. Duncan _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
