Re: Guile numerical work and uniform arrays

[Jim Blandy <jimb@red-bean.com>]

> > Should Guile call a hook associated with the array to free its space?
> 
> I can't think of exact reasons to shout "NO!", but that is what I want
> to do.  When things start to smell like C++, I get wary,
> 
> I think Guile should have the concept of "indirect" uniform vectors.
> These can appear in several situations: a pointer to something managed
> by C, a sub-vector of an existing vector, or as a "handle" to a
> vectored field of a record (heh, I had it all working here and then
> broke it :-().
> 
> In all the above situations, Guile's GC should have no control over
> the indirect vector.

Well, I guess what I had in mind was your indirect uniform vectors
(which Guile actually does have at the moment, if I understand the
code correctly), where Guile will call a function specified by the
owner of the underlying array when the indirect vector goes away.

If it's literally true that Guile's GC should have no control over the
underlying vector, then you can supply a null function for GC to call.
What I think you actually want in some circumstances is simply
notification that Guile isn't using the vector any more.  Which is all
the callback gives you.

Since the callback is implemented by the owner of the array, Guile's
GC not only has no control over the array, but will politely tell you
whether it's even referring to it.

Maybe it's still a bad idea.  I don't like destructors either.  But
that's my rationale.

> I have a (somewhat rough now) design for all this stuff.  When I get a
> couple of hours to quietly sit on it and write it all up, I'll post
> here.  Hopefull the fact that you see this promise will motivate me
> further :)

Looking forward to it.