From: David Kastrup <dak@gnu.org>
To: help-gnu-emacs@gnu.org
Subject: Re: Lists and Vectors
Date: Fri, 09 Oct 2009 12:44:20 +0200 [thread overview]
Message-ID: <87iqeodeyj.fsf@lola.goethe.zz> (raw)
In-Reply-To: 5c1869f3-21d3-4fef-aaac-635b43126751@v36g2000yqv.googlegroups.com
Nordlöw <per.nordlow@gmail.com> writes:
> If I have an association list say,
>
> '(
> ("key" sym1 val1 num1)
> ("key2" sym2 val2 num2)
> )
>
> , where each entry is a fixed sequence of various objects. I might
> aswell use a vector to represent an entry in this alist, right?
>
> In this case, what do I gain by using a vector instead of list?
conses.
> What about performance?: aref() faster than nth() only for large
> vectors?
Mostly.
> Is there vector-variant of assoc()? If not, why? Has any one already
> written such a function?
You would only put sym, val, num into the vector. If your association
list is long enough that key lookup would become slow, you'd rather use
a hashtable.
--
David Kastrup
next prev parent reply other threads:[~2009-10-09 10:44 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-09 10:28 Lists and Vectors Nordlöw
2009-10-09 10:44 ` David Kastrup [this message]
2009-10-09 17:19 ` Pascal J. Bourguignon
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