From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.bugs Subject: bug#8611: fixnum arithmetic should not wrap around Date: Tue, 03 May 2011 18:19:26 -0700 Organization: UCLA Computer Science Department Message-ID: <4DC0A99E.3090706@cs.ucla.edu> References: <4DC0491D.7090404@cs.ucla.edu> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Trace: dough.gmane.org 1304473025 28338 80.91.229.12 (4 May 2011 01:37:05 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Wed, 4 May 2011 01:37:05 +0000 (UTC) Cc: 8611@debbugs.gnu.org To: Stefan Monnier Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Wed May 04 03:37:00 2011 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1QHR1Q-0004ej-NF for geb-bug-gnu-emacs@m.gmane.org; Wed, 04 May 2011 03:37:00 +0200 Original-Received: from localhost ([::1]:36503 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QHR1Q-0008Ey-93 for geb-bug-gnu-emacs@m.gmane.org; Tue, 03 May 2011 21:37:00 -0400 Original-Received: from eggs.gnu.org ([140.186.70.92]:37171) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QHR1M-0008Cb-Rq for bug-gnu-emacs@gnu.org; Tue, 03 May 2011 21:36:57 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QHR1L-0005uU-Gt for bug-gnu-emacs@gnu.org; Tue, 03 May 2011 21:36:56 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:33737) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QHR1L-0005uQ-E9 for bug-gnu-emacs@gnu.org; Tue, 03 May 2011 21:36:55 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.69) (envelope-from ) id 1QHQl1-0002bU-Aa; Tue, 03 May 2011 21:20:03 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Paul Eggert Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-To: owner@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 04 May 2011 01:20:03 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 8611 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 8611-submit@debbugs.gnu.org id=B8611.13044719869979 (code B ref 8611); Wed, 04 May 2011 01:20:03 +0000 Original-Received: (at 8611) by debbugs.gnu.org; 4 May 2011 01:19:46 +0000 Original-Received: from localhost ([127.0.0.1] helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1QHQkj-0002au-Lb for submit@debbugs.gnu.org; Tue, 03 May 2011 21:19:45 -0400 Original-Received: from smtp.cs.ucla.edu ([131.179.128.62]) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1QHQke-0002ac-GH for 8611@debbugs.gnu.org; Tue, 03 May 2011 21:19:45 -0400 Original-Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp.cs.ucla.edu (Postfix) with ESMTP id 523B439E8106; Tue, 3 May 2011 18:19:34 -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 Ci+tOb3mfR92; Tue, 3 May 2011 18:19:33 -0700 (PDT) Original-Received: from [192.168.1.10] (pool-71-189-109-235.lsanca.fios.verizon.net [71.189.109.235]) by smtp.cs.ucla.edu (Postfix) with ESMTPSA id AE11C39E80FA; Tue, 3 May 2011 18:19:33 -0700 (PDT) User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.14) Gecko/20110223 Thunderbird/3.1.8 In-Reply-To: X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list Resent-Date: Tue, 03 May 2011 21:20:03 -0400 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 140.186.70.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:46178 Archived-At: On 05/03/11 17:31, Stefan Monnier wrote: > Using floats has only been introduced in order to handle things like > file sizes larger than 4GB, i.e. the int-to-float conversion currently > only ever happens for values that come from some C function. Sorry, I don't follow. The Lisp reader currently sees "536870912" and generates a float. How is that "some C function"? The Lisp reader's behavior has nothing to do with the stat function or with file sizes or with anything other than how Emacs itself is implemented. I'm just trying to understand the general design principle here. On further thought: Would it be better to change Emacs to use bignums if available? I could do that, using GMP, I suppose. But surely it should return bignums consistently everywhere: the Lisp reader, string-to-number, arithmetic operations, etc. If bignums aren't feasible for some reason, and floats are our best approximation, shouldn't floats be used consistently whereever bignums would otherwise be used?