From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: Checking for loss of information on integer conversion Date: Sun, 18 Feb 2018 17:41:10 -0500 Message-ID: References: <7432641a-cedc-942c-d75c-0320fce5ba39@cs.ucla.edu> <87woza7wwi.fsf@trurl.irif.fr> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1518993598 1847 195.159.176.226 (18 Feb 2018 22:39:58 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sun, 18 Feb 2018 22:39:58 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.0.50 (gnu/linux) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sun Feb 18 23:39:54 2018 Return-path: Envelope-to: ged-emacs-devel@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 1enXcN-0007Kz-Vm for ged-emacs-devel@m.gmane.org; Sun, 18 Feb 2018 23:39:36 +0100 Original-Received: from localhost ([::1]:46797 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1enXeQ-00030Z-7Q for ged-emacs-devel@m.gmane.org; Sun, 18 Feb 2018 17:41:42 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:35073) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1enXeJ-00030L-Je for emacs-devel@gnu.org; Sun, 18 Feb 2018 17:41:36 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1enXeH-0004ox-1C for emacs-devel@gnu.org; Sun, 18 Feb 2018 17:41:35 -0500 Original-Received: from [195.159.176.226] (port=57775 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1enXeG-0004oQ-NW for emacs-devel@gnu.org; Sun, 18 Feb 2018 17:41:32 -0500 Original-Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1enXc4-0006AT-Ea for emacs-devel@gnu.org; Sun, 18 Feb 2018 23:39:16 +0100 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 15 Original-X-Complaints-To: usenet@blaine.gmane.org Cancel-Lock: sha1:wpgO9Oje/v3LawmNwqaDHd9/ilU= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 195.159.176.226 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 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:222887 Archived-At: >> Another possibility would be for Emacs to signal an error when reading any >> integer that does not fit in fixnum bounds. > Please do that. That would be a regression. On 32bit systems, there are various circumstances where we need to read a 32bit ID (i.e. one that doesn't fit within our 30bit fixnums), as well as situations where we read something like a file size which may also fail to fit. On 64bit systems (and 32bit systems built with wide-ints), I don't see such a clear need to convert a large integer into a float, so on those systems I think it's OK to just signal an error. Stefan "still living in the 32bit world"