Re: obarray confusion

[Pascal J. Bourguignon]

David Kastrup <dak@gnu.org> writes:

> pjb@informatimago.com (Pascal J. Bourguignon) writes:
>
>> Sean McAfee <eefacm@gmail.com> writes:
>>
>>> (mapatoms (lambda (s) (incf n))) tells me I have 43061 symbols defined.
>>> (length obarray) tells me the standard obarray has a size of 1511.
>>>
>>> My understanding is that an obarray is essentially a hash table with
>>> collision chaining.  But this would mean that the linked list of symbols
>>> in each bucket has an average length of 43061 / 1511 ≈ 28.
>>>
>>> Emacs's symbol lookup couldn't possibly be that inefficient, could it?
>>
>> Symbols are interned only when they are read, which doesn't occur often.
>
> 28 is quite the bucket size.  If the average bucket size is larger than
> 1 for the dumped Emacs already, that's just a case of bad defaults, and
> of course it should affect byte compilation times quite a bit.

Obviously, emacs is optimized for editing, not for compiling ;-)

I agree that the size of the obarray should adapt to its content.


-- 
__Pascal Bourguignon__                     http://www.informatimago.com/