From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Lars Ingebrigtsen Newsgroups: gmane.emacs.devel Subject: Re: encode-time vs decode-time Date: Sun, 11 Aug 2019 16:39:19 -0700 Message-ID: <87mugfz2zc.fsf@mouse.gnus.org> References: <502b23f8-58ed-38ff-ae50-fae391129a10@cs.ucla.edu> <87v9viuivo.fsf@mouse.gnus.org> <83blx2cr2o.fsf@gnu.org> <8336iecfvr.fsf@gnu.org> <68d24d6a-d427-baef-27e9-ea1cbbd64c18@cs.ucla.edu> <83pnlhav7t.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="252322"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.0.50 (gnu/linux) Cc: eggert@cs.ucla.edu, andrewjmoreton@gmail.com, Stefan Monnier , emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Aug 12 01:39:49 2019 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hwxRD-0013Vo-F1 for ged-emacs-devel@m.gmane.org; Mon, 12 Aug 2019 01:39:47 +0200 Original-Received: from localhost ([::1]:42130 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hwxRB-0000cU-Pu for ged-emacs-devel@m.gmane.org; Sun, 11 Aug 2019 19:39:45 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:42509) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hwxR7-0000cM-01 for emacs-devel@gnu.org; Sun, 11 Aug 2019 19:39:42 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hwxR5-00050Y-V3 for emacs-devel@gnu.org; Sun, 11 Aug 2019 19:39:40 -0400 Original-Received: from quimby.gnus.org ([80.91.231.51]:56916) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hwxR5-000509-Oh; Sun, 11 Aug 2019 19:39:39 -0400 Original-Received: from 107-182-45-44.volcanocom.com ([107.182.45.44] helo=sandy) by quimby.gnus.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hwxQp-0007ux-Vi; Mon, 12 Aug 2019 01:39:26 +0200 In-Reply-To: <83pnlhav7t.fsf@gnu.org> (Eli Zaretskii's message of "Wed, 07 Aug 2019 17:47:18 +0300") X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 80.91.231.51 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 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:239327 Archived-At: Eli Zaretskii writes: >> Actually, while I agree that it's possible it will break something >> somewhere, it's rather unlikely. > > I think our record of making such predictions is rather poor. > > And anyway, suppose someone comes up with complaints about this > change: what exactly do we say in response? The reason for the change > is quite weak: it's basically an enhancement required by somewhat rare > niche use cases. How can we justify breaking someone's code on such > weak grounds? Having sub-second time resolution in calendar dates doesn't seem like a minor thing to me. I think if you say "now Emacs is ISO8601 compliant", then it's all the justification anybody could possibly need. I also think this is probably less likely to break anybody's code than when Emacs changed the output from `current-time' from being a list of two integers to four integers. The only possible real world problem I can see being slightly likely is somebody writing the output of `decode-time' to a file, and then reading it back in again. If the writer is a new Emacs, and the reader is an old Emacs (that calls `encode-time' on the data), then things will probably break. But I don't know of anybody doing stuff like that. -- (domestic pets only, the antidote for overdose, milk.) bloggy blog: http://lars.ingebrigtsen.no