From mboxrd@z Thu Jan  1 00:00:00 1970
Path: main.gmane.org!not-for-mail
From: Eli Zaretskii <eliz@gnu.org>
Newsgroups: gmane.emacs.devel
Subject: Re: performance of converting alist to hash table
Date: 16 May 2004 13:18:07 +0200
Sender: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org
Message-ID: <uy8nsy61c.fsf@gnu.org>
References: <20040516095522.GA1625@SDF.LONESTAR.ORG>
Reply-To: Eli Zaretskii <eliz@gnu.org>
NNTP-Posting-Host: deer.gmane.org
X-Trace: sea.gmane.org 1084702838 15505 80.91.224.253 (16 May 2004 10:20:38 GMT)
X-Complaints-To: usenet@sea.gmane.org
NNTP-Posting-Date: Sun, 16 May 2004 10:20:38 +0000 (UTC)
Cc: emacs-devel@gnu.org
Original-X-From: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Sun May 16 12:20:32 2004
Return-path: <emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org>
Original-Received: from quimby.gnus.org ([80.91.224.244])
	by deer.gmane.org with esmtp (Exim 3.35 #1 (Debian))
	id 1BPIky-0004ys-00
	for <emacs-devel@deer.gmane.org>; Sun, 16 May 2004 12:20:32 +0200
Original-Received: from monty-python.gnu.org ([199.232.76.173])
	by quimby.gnus.org with esmtp (Exim 3.35 #1 (Debian))
	id 1BPIkx-0006eF-00
	for <emacs-devel@quimby.gnus.org>; Sun, 16 May 2004 12:20:31 +0200
Original-Received: from localhost ([127.0.0.1] helo=monty-python.gnu.org)
	by monty-python.gnu.org with esmtp (Exim 4.34)
	id 1BPIjL-0004Js-I2
	for emacs-devel@quimby.gnus.org; Sun, 16 May 2004 06:18:51 -0400
Original-Received: from list by monty-python.gnu.org with tmda-scanned (Exim 4.34)
	id 1BPIif-0004H4-Ko
	for emacs-devel@gnu.org; Sun, 16 May 2004 06:18:09 -0400
Original-Received: from mail by monty-python.gnu.org with spam-scanned (Exim 4.34)
	id 1BPIgk-0003GM-Fm
	for emacs-devel@gnu.org; Sun, 16 May 2004 06:16:50 -0400
Original-Received: from [207.232.27.5] (helo=WST0035)
	by monty-python.gnu.org with asmtp (Exim 4.34)
	id 1BPIgi-0003Dl-EN; Sun, 16 May 2004 06:16:09 -0400
Original-To: Dai Yuwen <daiyuwen@sdf.lonestar.org>
In-reply-to: <20040516095522.GA1625@SDF.LONESTAR.ORG> (message from Dai Yuwen
	on Sun, 16 May 2004 09:55:22 +0000)
X-BeenThere: emacs-devel@gnu.org
X-Mailman-Version: 2.1.4
Precedence: list
List-Id: "Emacs development discussions." <emacs-devel.gnu.org>
List-Unsubscribe: <http://mail.gnu.org/mailman/listinfo/emacs-devel>,
	<mailto:emacs-devel-request@gnu.org?subject=unsubscribe>
List-Archive: <http://mail.gnu.org/pipermail/emacs-devel>
List-Post: <mailto:emacs-devel@gnu.org>
List-Help: <mailto:emacs-devel-request@gnu.org?subject=help>
List-Subscribe: <http://mail.gnu.org/mailman/listinfo/emacs-devel>,
	<mailto:emacs-devel-request@gnu.org?subject=subscribe>
Errors-To: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org
Xref: main.gmane.org gmane.emacs.devel:23525
X-Report-Spam: http://spam.gmane.org/gmane.emacs.devel:23525

> Date: Sun, 16 May 2004 09:55:22 +0000
> From: Dai Yuwen <daiyuwen@sdf.lonestar.org>
> 
> I'm trying to convert a large alist(nearly 7000 elements in it) to a
> hash table. But I found the performence of my function is poor: on a
> Celeron 333MHz, 196M memory system, it'll take 15 seconds to finish
> converting. 
> 
> This is the function:
> 
> (defun convert-alist-to-hash (table  w)
>   (let ((l w))
>      (while l
>        (setq char (car (car l))
>              key (car (cdr (car l)))
>              l (cdr l))
>        (puthash char key table))))

Did you try `mapcar' and its variants?