Re: Physical counterpart to Pervasives.compare?

Re: Physical counterpart to Pervasives.compare?

[Pascal Cuoq]

Christophe Raffalli <christophe.raffalli@univ-savoie.fr> wrote:
> Or, if all major GCs are compacting and the minor heap is at
> a higher adress than the major heap, then OCaml's could also
> preserve the adress order between GC ...

I do not think that the current minor GC algorithm does
any effort to copy the live blocks from the minor heap in order
(i.e. to copy first the blocks with the lower addresses).
It copies them as it finds them, recursively. Two blocks from
the minor heap may still see the order in which they are
in memory change when they are both copied
to the major heap.
For this reason, I do not think that the above trick would work.

Pascal

Physical counterpart to Pervasives.compare?

[Elnatan Reisner]

Is there something that can complete this analogy:
(=) is to (==) as Pervasives.compare is to ___?

That is, is there a polymorphic total ordering with respect to *physical*
entities, rather than to their structure?

I'm afraid of getting into trouble with Obj.magic, but what would this do:
let f (x:'a) (y:'a) = compare (Obj.magic x) (Obj.magic y)
? Or would annotations make any difference:
let f (x:'a) (y:'a) = compare (Obj.magic x : int) (Obj.magic y : int)

-Elnatan