From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: =?ISO-8859-15?Q?Andreas_R=F6hler?= Newsgroups: gmane.emacs.devel Subject: Re: Should undefined behavior be encouraged in Emacs? Date: Mon, 03 Oct 2011 08:39:01 +0200 Message-ID: <4E895885.5060201@online.de> References: <4E89124D.8070405@cs.ucla.edu> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit X-Trace: dough.gmane.org 1317623960 6931 80.91.229.12 (3 Oct 2011 06:39:20 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Mon, 3 Oct 2011 06:39:20 +0000 (UTC) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Oct 03 08:39:16 2011 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([140.186.70.17]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1RAcBH-000244-CR for ged-emacs-devel@m.gmane.org; Mon, 03 Oct 2011 08:39:15 +0200 Original-Received: from localhost ([::1]:46708 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RAcBG-0006Mg-El for ged-emacs-devel@m.gmane.org; Mon, 03 Oct 2011 02:39:14 -0400 Original-Received: from eggs.gnu.org ([140.186.70.92]:51013) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RAcBE-0006Mb-N5 for emacs-devel@gnu.org; Mon, 03 Oct 2011 02:39:13 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RAcBD-0001wj-Gb for emacs-devel@gnu.org; Mon, 03 Oct 2011 02:39:12 -0400 Original-Received: from moutng.kundenserver.de ([212.227.17.9]:64663) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RAcBD-0001vm-5Z for emacs-devel@gnu.org; Mon, 03 Oct 2011 02:39:11 -0400 Original-Received: from [192.168.178.27] (brln-4dbc509b.pool.mediaWays.net [77.188.80.155]) by mrelayeu.kundenserver.de (node=mreu3) with ESMTP (Nemesis) id 0MTact-1RcMTk04cZ-00S0n7; Mon, 03 Oct 2011 08:39:07 +0200 User-Agent: Mozilla/5.0 (X11; U; Linux i686; de; rv:1.9.2.22) Gecko/20110907 SUSE/3.1.14 Thunderbird/3.1.14 In-Reply-To: X-Provags-ID: V02:K0:a4ll9JTXVVbiLa/47aKerHSP6dK+bV98Pt8XY7hqqNP 6Bgy2q6VIatcduXRaWi/DySOm8XXj+G8yn6bhdrkPazXwGtUOs jg+7BXpilR9RJgkeUXv9EPs1N7pQA3QtnN8b2cFDNcYroJKsl+ HjAqbHVgTK0iO9ISC0IN6M41Er1rcObQKRjDJCHUrAq+Is0BU3 HVTMyXel4zsKkaSflWMU//TYm7ncxhYJ21aw+1qVX4UDGG+Ezl /pc7mMpV7s7uR5qQWeRu6XGJVojIoztAjnbgpFnsnYgFLGxv58 e173LLvk502GqsEnNIYIbONuo7MaCjt8HbuVsMO6vtPYWjYyBw 0JPxRPiYliXEdocoX/EuZ9P86ShuBUQa9FOfPA+ns X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 212.227.17.9 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:144533 Archived-At: Am 03.10.2011 05:11, schrieb Stefan Monnier: >> The argument given for undefined behavior is that it simplifies >> maintenance of Emacs internals. > > I like to keep some corner of the behavior undefined, when I think > that user code that depends on such details is undesirable (e.g. return > values of primitives which are only called for side-effects). > > > Stefan > > Hi, my bet: undefined behavior sources bugs, makes maintenance difficult. Design at the user level certainly deserves a separate approach. It's up to implement convenient error-handling than rather than undefined behavior. Cheers, Andreas