From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: Using the GNU GMP Library for Bignums in Emacs Date: Sat, 21 Apr 2018 09:08:03 -0700 Organization: UCLA Computer Science Department Message-ID: <55c1e23c-1b9d-1a95-c683-5bf453967c51@cs.ucla.edu> References: <29f933ac-a6bf-8742-66a7-0a9d6d3e5a88@disroot.org> <83bmecy6fx.fsf@gnu.org> <0d3175d8-d996-651e-b221-71978bde3a65@cs.ucla.edu> <51e619e0-ee38-eb97-6c1d-0925b675290a@disroot.org> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Trace: blaine.gmane.org 1524326830 21819 195.159.176.226 (21 Apr 2018 16:07:10 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 21 Apr 2018 16:07:10 +0000 (UTC) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 Cc: emacs-devel@gnu.org To: "Siraphob (Ben) Phipathananunth" , Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Apr 21 18:07:06 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 1f9v2U-0005XV-FL for ged-emacs-devel@m.gmane.org; Sat, 21 Apr 2018 18:07:02 +0200 Original-Received: from localhost ([::1]:55040 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f9v4b-0001lC-65 for ged-emacs-devel@m.gmane.org; Sat, 21 Apr 2018 12:09:13 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:51198) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f9v3e-0001k3-4O for emacs-devel@gnu.org; Sat, 21 Apr 2018 12:08:15 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f9v3d-0006WT-1d for emacs-devel@gnu.org; Sat, 21 Apr 2018 12:08:14 -0400 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:53046) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1f9v3Y-0006Rs-Fj; Sat, 21 Apr 2018 12:08:08 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 3910616005C; Sat, 21 Apr 2018 09:08:06 -0700 (PDT) Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id PmV5WtyTPZMx; Sat, 21 Apr 2018 09:08:05 -0700 (PDT) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 92BBD160860; Sat, 21 Apr 2018 09:08:04 -0700 (PDT) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id 3Ay-D9ezGqAS; Sat, 21 Apr 2018 09:08:03 -0700 (PDT) Original-Received: from [192.168.1.9] (unknown [47.154.30.119]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id C7AD616005C; Sat, 21 Apr 2018 09:08:03 -0700 (PDT) In-Reply-To: <51e619e0-ee38-eb97-6c1d-0925b675290a@disroot.org> Content-Language: en-US X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 131.179.128.68 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:224769 Archived-At: Siraphob (Ben) Phipathananunth wrote: > Hopefully there isn't existing > Emacs Lisp code that relies on unsafe arithmetic /anywhere/. I'm afraid your hope will be in vain.... And it depends on what we mean by "unsafe". Is it safe to assume that (eq= (1+ 0)=20 1) returns t, for example? The Scheme standard says "no" but we might dec= ide=20 that 'eq' should "work" for fixnums in Emacs Lisp. That sort of thing. > If the functions + - * / operate on bignums (instead of dedicated bignu= m > functions), would that mean we drop 32/64 bit integers entirely? No, it'd mean we'd still have fixnums vs bignums internally, and most pro= grams=20 wouldn't care whether an integer is represented via fixnum or bignum, as = it'd be=20 an issue merely of efficiency. Some programs would probably still care th= ough=20 (for efficiency reasons), and GNU Calc quite possibly would be one such p= rogram. > It would make much more sense to have separate math functions for 32/64 > bit numbers and for bignums. In doing so, it should be obvious to the > Emacs Lisp programmer when to use what. That's not how other Lisps work, by and large. They have just one integer= type=20 and one set of functions. The goal is to simplify the job of writing a pr= ogram.