On 13 August 2004 14:04, Remi Turk wrote:
How do you arrange to free a GMP integer when it is no longer referenced from the heap? You'd need finalizers, and that way lies madness. The memory allocation tricks we play with GMP are all to support GC of Integers.
Errr, I guess I'll have to start looking for a straitjacket then ;) Finalisers where exactly what I was thinking about, and though below implementation without doubt contains a bunch of bugs, perhaps even show-stoppers, the following code _does_ print True:
import Mpz
main= print $ show (z::Integer) == show (z::Mpz) where -- some random calculations x, y, z :: Blub a => a x = 2^64 - sum (take 100 $ iterate (63*) 3) y = 3^200 * 234233432 - (34 `pow` 38) + sum [1,87..20000] z = fac 5000 * (x + y) `div` (2^100)
Or are finalisers simply going to be too slow to take seriously for this?
You can't use mallocForeignPtr (because GMP needs to allocate its own memory), so you have to use full-blown ForeignPtrs with malloc/free and finalizers. Yes, these are very slow compared to using GC'd memory. Cheers, Simon