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Re: Length of obarray vectors
From: |
Pascal J. Bourguignon |
Subject: |
Re: Length of obarray vectors |
Date: |
Fri, 06 Nov 2009 13:03:59 +0100 |
User-agent: |
Gnus/5.1008 (Gnus v5.10.8) Emacs/22.3 (darwin) |
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__