From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Mark H Weaver Newsgroups: gmane.lisp.guile.bugs Subject: bug#30426: division inconsistency? Date: Mon, 12 Feb 2018 16:15:51 -0500 Message-ID: <87sha5q588.fsf@netris.org> References: <874lmlrkgc.fsf@netris.org> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1518470160 18693 195.159.176.226 (12 Feb 2018 21:16:00 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Mon, 12 Feb 2018 21:16:00 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.3 (gnu/linux) Cc: 30426@debbugs.gnu.org To: bil@ccrma.Stanford.EDU Original-X-From: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Mon Feb 12 22:15:55 2018 Return-path: Envelope-to: guile-bugs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1elLRT-0002AO-10 for guile-bugs@m.gmane.org; Mon, 12 Feb 2018 22:15:15 +0100 Original-Received: from localhost ([::1]:54294 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1elLTU-0000zV-Sq for guile-bugs@m.gmane.org; Mon, 12 Feb 2018 16:17:20 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:55001) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1elLTH-0000xS-E1 for bug-guile@gnu.org; Mon, 12 Feb 2018 16:17:10 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1elLTC-00013i-9e for bug-guile@gnu.org; Mon, 12 Feb 2018 16:17:07 -0500 Original-Received: from debbugs.gnu.org ([208.118.235.43]:60448) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1elLTC-00013I-6W for bug-guile@gnu.org; Mon, 12 Feb 2018 16:17:02 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1elLTB-0000yL-Tz for bug-guile@gnu.org; Mon, 12 Feb 2018 16:17:01 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Mark H Weaver Original-Sender: "Debbugs-submit" Resent-CC: bug-guile@gnu.org Resent-Date: Mon, 12 Feb 2018 21:17:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 30426 X-GNU-PR-Package: guile X-GNU-PR-Keywords: Original-Received: via spool by 30426-submit@debbugs.gnu.org id=B30426.15184701913694 (code B ref 30426); Mon, 12 Feb 2018 21:17:01 +0000 Original-Received: (at 30426) by debbugs.gnu.org; 12 Feb 2018 21:16:31 +0000 Original-Received: from localhost ([127.0.0.1]:40111 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1elLSh-0000xV-FE for submit@debbugs.gnu.org; Mon, 12 Feb 2018 16:16:31 -0500 Original-Received: from world.peace.net ([50.252.239.5]:50022) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1elLSf-0000xI-LZ for 30426@debbugs.gnu.org; Mon, 12 Feb 2018 16:16:29 -0500 Original-Received: from pool-72-93-28-59.bstnma.east.verizon.net ([72.93.28.59] helo=jojen) by world.peace.net with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1elLSa-0004jv-1Q; Mon, 12 Feb 2018 16:16:24 -0500 In-Reply-To: <874lmlrkgc.fsf@netris.org> (Mark H. Weaver's message of "Mon, 12 Feb 2018 16:01:39 -0500") X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 208.118.235.43 X-BeenThere: bug-guile@gnu.org 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" Xref: news.gmane.org gmane.lisp.guile.bugs:9004 Archived-At: Mark H Weaver writes: > Our core '/' operator, as defined in numbers.c, raises an exception for > (/ x 0), for any 'x'. This does not conform to the R6RS, which > specifies that (/ 0.0 0) => +inf.0. I don't think that rule makes sense Sorry, I meant to write (/ 1.0 0) => +inf.0, which is one of the examples given in the R6RS. > because the sign of the result cannot be justified. (/ 1 0.0) => +inf.0 > and (/ 1 -0.0) => -inf.0 are more justifiable because of the signed > inexact zeroes, but an exact zero is not signed. > > However, it may be that we should change this to conform to the R6RS, > and certainly it would be good for our compiler and interpreter to agree > on all of these edge cases. Mark