From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: (0 <= i && i < N) is not "backwards" Date: Mon, 25 Mar 2013 07:35:51 -0700 Organization: UCLA Computer Science Department Message-ID: <515060C7.2070602@cs.ucla.edu> References: <514F88E9.2020600@cs.ucla.edu> <83d2un3n7t.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1364222705 11043 80.91.229.3 (25 Mar 2013 14:45:05 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 25 Mar 2013 14:45:05 +0000 (UTC) Cc: schwab@linux-m68k.org, Emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Mar 25 15:45:32 2013 Return-path: Envelope-to: ged-emacs-devel@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 1UK8eP-0000HC-C7 for ged-emacs-devel@m.gmane.org; Mon, 25 Mar 2013 15:45:29 +0100 Original-Received: from localhost ([::1]:42157 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UK8e1-0004v1-DW for ged-emacs-devel@m.gmane.org; Mon, 25 Mar 2013 10:45:05 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:52884) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UK8Vg-0000GF-Ul for Emacs-devel@gnu.org; Mon, 25 Mar 2013 10:36:30 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UK8V7-0007zu-1N for Emacs-devel@gnu.org; Mon, 25 Mar 2013 10:35:54 -0400 Original-Received: from smtp.cs.ucla.edu ([131.179.128.62]:55950) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UK8V6-0007zE-QJ; Mon, 25 Mar 2013 10:35:52 -0400 Original-Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp.cs.ucla.edu (Postfix) with ESMTP id DFDCE39E8108; Mon, 25 Mar 2013 07:35:51 -0700 (PDT) X-Virus-Scanned: amavisd-new at smtp.cs.ucla.edu Original-Received: from smtp.cs.ucla.edu ([127.0.0.1]) by localhost (smtp.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id DsksIGePaYCW; Mon, 25 Mar 2013 07:35:51 -0700 (PDT) Original-Received: from [192.168.1.9] (pool-71-189-154-249.lsanca.fios.verizon.net [71.189.154.249]) by smtp.cs.ucla.edu (Postfix) with ESMTPSA id 7B2B639E8106; Mon, 25 Mar 2013 07:35:51 -0700 (PDT) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 In-Reply-To: <83d2un3n7t.fsf@gnu.org> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x X-Received-From: 131.179.128.62 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 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-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:158144 Archived-At: On 03/25/2013 01:20 AM, Eli Zaretskii wrote: > Out of fairness, you introduced this style into Emacs sources I've certainly used it in the changes I made, and as a result it's become more popular, but I did not introduce it. That style has been used in Emacs, as a minority style, for many years. > If we want our code to be robust in the face of NaNs, we should > probably use 'isnan' explicitly That will slow the code down and make it harder to read. Perhaps a comment could be introduced; but must we really add a comment "watch out for NaNs!" every time we have a floating point comparison? > whether a NaN > should be considered greater or less than zero in the Emacs context is > debatable The documentation for one of the affected variables says "If the value is not a number, ...", so the behavior formerly matched the documentation and now no longer does so. This was not the only bug introduced by the change, I'm afraid.