From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Helmut Eller Newsgroups: gmane.emacs.devel Subject: Re: Using the GNU GMP Library for Bignums in Emacs Date: Thu, 03 May 2018 08:26:05 +0200 Message-ID: References: <29f933ac-a6bf-8742-66a7-0a9d6d3e5a88@disroot.org> <83bmecy6fx.fsf@gnu.org> <0d3175d8-d996-651e-b221-71978bde3a65@cs.ucla.edu> <42cbc5ab-2f02-4aa5-4b19-7b2357f91692@cs.ucla.edu> <1f58acbf-a7d8-bf4e-3d0e-a285515a22e6@cs.ucla.edu> <2549728d-8e40-b46a-009e-07cef0c24208@cs.ucla.edu> <63fdd138-77d3-89b9-aa69-490300f588a9@cs.ucla.edu> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1525328826 17652 195.159.176.226 (3 May 2018 06:27:06 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Thu, 3 May 2018 06:27:06 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.0.50 (gnu/linux) Cc: Paul Eggert , rms@gnu.org To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu May 03 08:27:02 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 1fE7hl-0004TN-Ue for ged-emacs-devel@m.gmane.org; Thu, 03 May 2018 08:27:02 +0200 Original-Received: from localhost ([::1]:54214 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fE7js-0004Na-Tk for ged-emacs-devel@m.gmane.org; Thu, 03 May 2018 02:29:12 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:42111) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fE7hA-0002rE-LK for emacs-devel@gnu.org; Thu, 03 May 2018 02:26:25 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fE7h6-0004M0-N3 for emacs-devel@gnu.org; Thu, 03 May 2018 02:26:24 -0400 Original-Received: from [195.159.176.226] (port=38629 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fE7h6-0004Kc-Ff for emacs-devel@gnu.org; Thu, 03 May 2018 02:26:20 -0400 Original-Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1fE7et-0001YZ-O8 for emacs-devel@gnu.org; Thu, 03 May 2018 08:24:03 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 22 Original-X-Complaints-To: usenet@blaine.gmane.org Cancel-Lock: sha1:sToxU8GSzU9izgg02jWLA8OUXqc= 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:225042 Archived-At: On Wed, May 02 2018, Paul Eggert wrote: > Richard Stallman wrote: >> That means the feature would need to specify the number of hex digits >> desired. > > We already have such a feature. For example, (format "%09x" 257) returns > "000000101", which is 257 hexadecimal, expressed using leading zeros > as needed so that at least 9 digits are used. Once Emacs supports > bignums, the same feature can print 40-hex-digit SHA-1 checksums by > using (format "%040x" n). I think the bitwise operations and the resulting negative numbers are the problematic part: E.g. (format "%016x" (lognot 257)) => "3ffffffffffffefe" but the 16-hex-digit string should be "fffffffffffffefe". Helmut