From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.help Subject: Re: no empty (zero) string predicate in Elisp Date: Sun, 26 Apr 2015 17:25:47 -0400 Message-ID: References: <87h9s4rhx5.fsf@debian.uxu> <874mo4jmb7.fsf@kuiper.lan.informatimago.com> <87wq0zild3.fsf@kuiper.lan.informatimago.com> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1430083615 32155 80.91.229.3 (26 Apr 2015 21:26:55 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 26 Apr 2015 21:26:55 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Sun Apr 26 23:26:47 2015 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1YmU4a-0006M8-Hz for geh-help-gnu-emacs@m.gmane.org; Sun, 26 Apr 2015 23:26:44 +0200 Original-Received: from localhost ([::1]:52269 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YmU4Z-0003i6-Qa for geh-help-gnu-emacs@m.gmane.org; Sun, 26 Apr 2015 17:26:43 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:52655) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YmU4O-0003fN-8n for help-gnu-emacs@gnu.org; Sun, 26 Apr 2015 17:26:32 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YmU4L-0001vQ-4t for help-gnu-emacs@gnu.org; Sun, 26 Apr 2015 17:26:32 -0400 Original-Received: from plane.gmane.org ([80.91.229.3]:44970) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YmU4K-0001vF-Tt for help-gnu-emacs@gnu.org; Sun, 26 Apr 2015 17:26:29 -0400 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1YmU4I-000643-U9 for help-gnu-emacs@gnu.org; Sun, 26 Apr 2015 23:26:27 +0200 Original-Received: from modemcable190.222-203-24.mc.videotron.ca ([24.203.222.190]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sun, 26 Apr 2015 23:26:26 +0200 Original-Received: from monnier by modemcable190.222-203-24.mc.videotron.ca with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sun, 26 Apr 2015 23:26:26 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 16 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: modemcable190.222-203-24.mc.videotron.ca User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.0.50 (gnu/linux) Cancel-Lock: sha1:2qLxUkypWxVZ3g4jq2+vVIsGFfQ= X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 80.91.229.3 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:104013 Archived-At: > This is exactly what I'm pointing to! If you want to consider how elisp > intgers are encoded on the native machine, then you definitely want a > zerop function, because there are BEQ and SEQ instructions. But that's not the case: Elisp is compiled to Emacs's byte-code "machine" which does not have such instructions. > Not in emacs-version "24.3.1" where I produced the disassembly > provided. But I'm happy to see it being optimized, this is one more > reason to keep it and use it. Indeed, the inefficiency of zerop was pointed out "recently" and has I think it's only fixed in Emacs-25. Stefan