From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: Any interest in a function like this to add to subr.el? Date: Wed, 19 Oct 2016 21:48:15 -0400 Message-ID: References: <68978e0f-03a3-70ec-c18a-e2d12f91ea5c@yandex.ru> <6d541e6d-f7a1-beba-77f5-94d5a06f93cb@yandex.ru> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1476928158 8404 195.159.176.226 (20 Oct 2016 01:49:18 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Thu, 20 Oct 2016 01:49:18 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1.50 (gnu/linux) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Oct 20 03:49:14 2016 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1bx2TR-00077u-1i for ged-emacs-devel@m.gmane.org; Thu, 20 Oct 2016 03:48:49 +0200 Original-Received: from localhost ([::1]:51875 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bx2TT-0004S1-8Y for ged-emacs-devel@m.gmane.org; Wed, 19 Oct 2016 21:48:51 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:38917) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bx2TL-0004Rw-HW for emacs-devel@gnu.org; Wed, 19 Oct 2016 21:48:44 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bx2TG-0003qU-Nm for emacs-devel@gnu.org; Wed, 19 Oct 2016 21:48:43 -0400 Original-Received: from [195.159.176.226] (port=52763 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1bx2TG-0003pa-Gd for emacs-devel@gnu.org; Wed, 19 Oct 2016 21:48:38 -0400 Original-Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1bx2T5-0004Ry-EE for emacs-devel@gnu.org; Thu, 20 Oct 2016 03:48:27 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 11 Original-X-Complaints-To: usenet@blaine.gmane.org Cancel-Lock: sha1:84/hjgnddAELUlZDvT0r4seegFw= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 195.159.176.226 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:208518 Archived-At: >>> We'd want a destructive version of it as well, though. >> Why? > I was thinking for performance. I'd find it really surprising if N uses of `cons` would be sufficiently more expensive than N uses of `setcar` not to be drowned by the O(N*log N) funcalls and other processing. But it wouldn't be the first time I was wrong, of course. Stefan