[rucksack-devel] How do you use rucksack?

[Arthur Lemmens]

Hi Christophe,

> I began to investigate building a simple application over the weekend,
> along the lines of an addressbook, and I thought I'd give rucksack a
> try for the persistent storage facility.  However, I quickly ran up
> against the problem of wanting to delete objects from indices.

Yeah, that's becoming something of a FAQ.  You may want to try out the
brand new RUCKSACK-DELETE-OBJECT function, which removes an object from
the root set (if necessary) and from all class and slot indexes in which
it appears.  I committed this function to the CVS repository today.

I haven't tested this function yet, and I'd be interested to know if it
works for you.

> Anything which is indexed is a root for the garbage collector, so it
> would appear that I can't have both indexing over some property of a
> class and also have instances of that class ever be reclaimed by the
> garbage collector.  Is that right?

Yes, that's right.  But you can remove an object from indexes; see the
implementation of RUCKSACK-DELETE-OBJECT.

If this doesn't answer your question, let me know.

Arthur