From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: Return Date: Mon, 06 Dec 2010 14:11:47 -0500 Message-ID: References: <87mxojwu15.fsf@uwakimon.sk.tsukuba.ac.jp> <87k4jnweng.fsf@uwakimon.sk.tsukuba.ac.jp> <87fwubb7j2.fsf@lola.goethe.zz> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: dough.gmane.org 1291662843 8857 80.91.229.12 (6 Dec 2010 19:14:03 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Mon, 6 Dec 2010 19:14:03 +0000 (UTC) Cc: emacs-devel@gnu.org To: David Kastrup Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Dec 06 20:13:59 2010 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1PPgVY-000064-Ui for ged-emacs-devel@m.gmane.org; Mon, 06 Dec 2010 20:13:57 +0100 Original-Received: from localhost ([127.0.0.1]:58875 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PPgVY-00050o-9H for ged-emacs-devel@m.gmane.org; Mon, 06 Dec 2010 14:13:56 -0500 Original-Received: from [140.186.70.92] (port=43016 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PPgTX-0003t5-BI for emacs-devel@gnu.org; Mon, 06 Dec 2010 14:11:52 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PPgTW-000129-CR for emacs-devel@gnu.org; Mon, 06 Dec 2010 14:11:51 -0500 Original-Received: from ironport2-out.teksavvy.com ([206.248.154.183]:23462 helo=ironport2-out.pppoe.ca) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PPgTU-00011j-VI; Mon, 06 Dec 2010 14:11:49 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AicIAE/E/ExFxLmf/2dsb2JhbACiMIELcr5XhUkEhF+NfQ X-IronPort-AV: E=Sophos;i="4.59,306,1288584000"; d="scan'208";a="84683501" Original-Received: from 69-196-185-159.dsl.teksavvy.com (HELO ceviche.home) ([69.196.185.159]) by ironport2-out.pppoe.ca with ESMTP/TLS/ADH-AES256-SHA; 06 Dec 2010 14:11:48 -0500 Original-Received: by ceviche.home (Postfix, from userid 20848) id 95378661BF; Mon, 6 Dec 2010 14:11:47 -0500 (EST) In-Reply-To: <87fwubb7j2.fsf@lola.goethe.zz> (David Kastrup's message of "Mon, 06 Dec 2010 10:00:17 +0100") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.0.50 (gnu/linux) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:133464 Archived-At: > If you take a look at Elisp programs, you'll notice that in practice it > is primarily used as an imperative language, not a functional language > (that is: the focus is on executing actions, not on constructing > values). It doesn't really help that the fundamental data structure, > the list, is not an abstract data type but realised via a rather > low-level pointer to a statically allocated pair of user-accessible > values, cutting right through the idea of "functional programming" where > the output is a mathematic function/transformation of the input. Actually, I think that the cons cells are relatively harmless in this regard (setcar/setcdr are not used that often, tho maybe slightly more so via delq and friends) compared to the blow incurred by the inefficiency of Elisp recursion. Stefan