From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Hans Aberg Newsgroups: gmane.lisp.guile.bugs Subject: Re: (+ (values 1 2)) should be 1 Date: Wed, 25 May 2011 10:41:23 +0200 Message-ID: <1BCD41C1-8A89-4202-B8E2-761790E2A0A0@telia.com> References: <6B109ACE-F9E4-463D-8314-A19CC40D5B50@telia.com> <87ei3nk4mg.fsf@netris.org> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable X-Trace: dough.gmane.org 1306337091 16141 80.91.229.12 (25 May 2011 15:24:51 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Wed, 25 May 2011 15:24:51 +0000 (UTC) Cc: bug-guile To: Mark H Weaver Original-X-From: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Wed May 25 17:24:47 2011 Return-path: Envelope-to: guile-bugs@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 1QPFwy-0005s8-IP for guile-bugs@m.gmane.org; Wed, 25 May 2011 17:24:44 +0200 Original-Received: from localhost ([::1]:42910 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QPFwy-0003Rb-5S for guile-bugs@m.gmane.org; Wed, 25 May 2011 11:24:44 -0400 Original-Received: from eggs.gnu.org ([140.186.70.92]:51348) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QPFwm-00034O-OJ for bug-guile@gnu.org; Wed, 25 May 2011 11:24:33 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QPFwl-00061O-RQ for bug-guile@gnu.org; Wed, 25 May 2011 11:24:32 -0400 Original-Received: from smtp-out11.han.skanova.net ([195.67.226.200]:53086) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QPFwl-0005zj-Cr for bug-guile@gnu.org; Wed, 25 May 2011 11:24:31 -0400 Original-Received: from [10.0.1.2] (217.210.127.13) by smtp-out11.han.skanova.net (8.5.133) (authenticated as u26619196) id 4D6512CA0231B1A2; Wed, 25 May 2011 10:41:25 +0200 In-Reply-To: <87ei3nk4mg.fsf@netris.org> X-Mailer: Apple Mail (2.1084) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 195.67.226.200 X-BeenThere: bug-guile@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Bug reports for GUILE, GNU's Ubiquitous Extension Language" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Original-Sender: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.bugs:5618 Archived-At: On 25 May 2011, at 02:25, Mark H Weaver wrote: >> Right, but as the result is unspecified according to the standard, = the >> Guile manual suggests that the value SCM_UNSPECIFIED as an >> interpretation of that. I merely say that I think it would be a good >> idea. ... > Having said all this, one could still make the case that we should > attempt to return SCM_UNSPECIFIED from expressions whose values are > unspecified by the standards whenever _practical_. However, doing = this > would prevent us from implementing extensions to many aspects of the > standard. Then sec. 10.2.5.2 of the manual needs to be clarified. It should say if = a returned value is SCM_UNSPECIFIED then the standard says it is = unspecified, but not the other way around. > Let's always keep in mind these two common rationales for unspecified > behavior in language specifications: >=20 > * to allow more efficient implementation > * to allow extensions to the standard Then it agrees with this for unspecified values. Hans