Re: Object identity

[Barry Margolin]

In article <jwv3cdm7d8k.fsf-monnier+gnu.emacs.help@vor.iro.umontreal.ca>,
Stefan Monnier  <monnier@iro.umontreal.ca> wrote:
>>> I still have no clue what it's useful for, so I tend to find such research
>>> rather pointless.  But I'm probably just missing the point.
>
>> The OP explained what it's useful for: emulating weak hash tables in a
>> system that doesn't have them built in.
>
>That's not how I understood his article.  He seemed to say that he
>currently uses an implementation of object-identity which relies
>on a weak hash-table but that his Emacs's doesn't implement weakness.
>I.e. he seemed to say he needed weak hash-tables to implement
>oject-identity, not the other way around.

I just reread it and you're correct.

>> it's likely that this overhead will be much greater than the memory leak in
>> his application.
>
>If the application is long running a 50% overhead can still be
>significantly better than a memory leak.

50% overhead on every object versus leaking something like 1% of objects.
I think I'd prefer the latter.

-- 
Barry Margolin, barry.margolin@level3.com
Level(3), Woburn, MA
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