* Length of obarray vectors
@ 2009-11-06 10:18 Nordlöw
2009-11-06 10:20 ` Nordlöw
0 siblings, 1 reply; 4+ messages in thread
From: Nordlöw @ 2009-11-06 10:18 UTC (permalink / raw)
To: help-gnu-emacs
What length should I use when I create a vector that will act as an
obarray?
My suggestion: The smallest prime larger than the number of symbols
that should be interned?
If this is correct why does (length obarray) give such a small number,
15
Thanks,
Nordlöw
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Length of obarray vectors
2009-11-06 10:18 Length of obarray vectors Nordlöw
@ 2009-11-06 10:20 ` Nordlöw
2009-11-06 11:16 ` Pascal J. Bourguignon
0 siblings, 1 reply; 4+ messages in thread
From: Nordlöw @ 2009-11-06 10:20 UTC (permalink / raw)
To: help-gnu-emacs
On Nov 6, 11:18 am, Nordlöw <per.nord...@gmail.com> wrote:
> What length should I use when I create a vector that will act as an
> obarray?
> My suggestion: The smallest prime larger than the number of symbols
> that should be interned?
> If this is correct why does (length obarray) give such a small number,
> 15
>
> Thanks,
> Nordlöw
It should be 1511, not 15.
Forgot one thing: My guess: Is it a trade-off of performance (big
length) and memory usage (small length)?
Thanks,
Nordlöw
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Length of obarray vectors
2009-11-06 10:20 ` Nordlöw
@ 2009-11-06 11:16 ` Pascal J. Bourguignon
2009-11-06 12:03 ` Pascal J. Bourguignon
0 siblings, 1 reply; 4+ messages in thread
From: Pascal J. Bourguignon @ 2009-11-06 11:16 UTC (permalink / raw)
To: help-gnu-emacs
Nordlöw <per.nordlow@gmail.com> writes:
> On Nov 6, 11:18 am, Nordlöw <per.nord...@gmail.com> wrote:
>> What length should I use when I create a vector that will act as an
>> obarray?
>> My suggestion: The smallest prime larger than the number of symbols
>> that should be interned?
>> If this is correct why does (length obarray) give such a small number,
>> 15
>>
>> Thanks,
>> Nordlöw
>
> It should be 1511, not 15.
>
> Forgot one thing: My guess: Is it a trade-off of performance (big
> length) and memory usage (small length)?
The reason is that obarrays are not arrays, but trees. You're watching
only the root of the tree.
--
__Pascal Bourguignon__
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Length of obarray vectors
2009-11-06 11:16 ` Pascal J. Bourguignon
@ 2009-11-06 12:03 ` Pascal J. Bourguignon
0 siblings, 0 replies; 4+ messages in thread
From: Pascal J. Bourguignon @ 2009-11-06 12:03 UTC (permalink / raw)
To: help-gnu-emacs
pjb@informatimago.com (Pascal J. Bourguignon) writes:
> Nordlöw <per.nordlow@gmail.com> writes:
>
>> On Nov 6, 11:18 am, Nordlöw <per.nord...@gmail.com> wrote:
>>> What length should I use when I create a vector that will act as an
>>> obarray?
>>> My suggestion: The smallest prime larger than the number of symbols
>>> that should be interned?
>>> If this is correct why does (length obarray) give such a small number,
>>> 15
>>>
>>> Thanks,
>>> Nordlöw
>>
>> It should be 1511, not 15.
>>
>> Forgot one thing: My guess: Is it a trade-off of performance (big
>> length) and memory usage (small length)?
>
> The reason is that obarrays are not arrays, but trees. You're watching
> only the root of the tree.
Sorry, not trees, but kinds of hash-tables.
--
__Pascal Bourguignon__
^ permalink raw reply [flat|nested] 4+ messages in thread
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2009-11-06 10:18 Length of obarray vectors Nordlöw
2009-11-06 10:20 ` Nordlöw
2009-11-06 11:16 ` Pascal J. Bourguignon
2009-11-06 12:03 ` Pascal J. Bourguignon
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