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: Tue, 10 Jul 2018 09:01:44 -0700 Organization: UCLA Computer Science Department Message-ID: <8e0320d9-e0d0-2b57-57cc-2df4399f133c@cs.ucla.edu> References: <29f933ac-a6bf-8742-66a7-0a9d6d3e5a88@disroot.org> <83bmecy6fx.fsf@gnu.org> <0d3175d8-d996-651e-b221-71978bde3a65@cs.ucla.edu> <87tvpdnzgy.fsf@tromey.com> <4c2a814f-c254-29e5-39cf-11b5f2e5c9c8@cs.ucla.edu> <49d8ba62-c9a5-9203-d882-8e900b441ff3@cs.ucla.edu> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: blaine.gmane.org 1531238863 4434 195.159.176.226 (10 Jul 2018 16:07:43 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 10 Jul 2018 16:07:43 +0000 (UTC) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 Cc: emacs-devel@gnu.org To: Stefan Monnier Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Jul 10 18:07:39 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 1fcvAw-00011O-KM for ged-emacs-devel@m.gmane.org; Tue, 10 Jul 2018 18:07:38 +0200 Original-Received: from localhost ([::1]:48677 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fcvD1-0002JC-W1 for ged-emacs-devel@m.gmane.org; Tue, 10 Jul 2018 12:09:48 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:49432) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fcv5O-0004aW-1w for emacs-devel@gnu.org; Tue, 10 Jul 2018 12:01:58 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fcv5K-0003Bl-Sx for emacs-devel@gnu.org; Tue, 10 Jul 2018 12:01:54 -0400 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:45770) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fcv5K-0003BP-JN for emacs-devel@gnu.org; Tue, 10 Jul 2018 12:01:50 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 4A99D160780; Tue, 10 Jul 2018 09:01:49 -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 dRk7w1zvfh3r; Tue, 10 Jul 2018 09:01:47 -0700 (PDT) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 7284F1607BA; Tue, 10 Jul 2018 09:01:47 -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 lEys1PVSAFy0; Tue, 10 Jul 2018 09:01:47 -0700 (PDT) Original-Received: from Penguin.CS.UCLA.EDU (Penguin.CS.UCLA.EDU [131.179.64.200]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id 524FA160780; Tue, 10 Jul 2018 09:01:47 -0700 (PDT) Openpgp: preference=signencrypt Autocrypt: addr=eggert@cs.ucla.edu; prefer-encrypt=mutual; keydata= xsFNBEyAcmQBEADAAyH2xoTu7ppG5D3a8FMZEon74dCvc4+q1XA2J2tBy2pwaTqfhpxxdGA9 Jj50UJ3PD4bSUEgN8tLZ0san47l5XTAFLi2456ciSl5m8sKaHlGdt9XmAAtmXqeZVIYX/UFS 96fDzf4xhEmm/y7LbYEPQdUdxu47xA5KhTYp5bltF3WYDz1Ygd7gx07Auwp7iw7eNvnoDTAl KAl8KYDZzbDNCQGEbpY3efZIvPdeI+FWQN4W+kghy+P6au6PrIIhYraeua7XDdb2LS1en3Ss mE3QjqfRqI/A2ue8JMwsvXe/WK38Ezs6x74iTaqI3AFH6ilAhDqpMnd/msSESNFt76DiO1ZK QMr9amVPknjfPmJISqdhgB1DlEdw34sROf6V8mZw0xfqT6PKE46LcFefzs0kbg4GORf8vjG2 Sf1tk5eU8MBiyN/bZ03bKNjNYMpODDQQwuP84kYLkX2wBxxMAhBxwbDVZudzxDZJ1C2VXujC OJVxq2kljBM9ETYuUGqd75AW2LXrLw6+MuIsHFAYAgRr7+KcwDgBAfwhPBYX34nSSiHlmLC+ KaHLeCLF5ZI2vKm3HEeCTtlOg7xZEONgwzL+fdKo+D6SoC8RRxJKs8a3sVfI4t6CnrQzvJbB n6gxdgCu5i29J1QCYrCYvql2UyFPAK+do99/1jOXT4m2836j1wARAQABzSBQYXVsIEVnZ2Vy dCA8ZWdnZXJ0QGNzLnVjbGEuZWR1PsLBfgQTAQIAKAUCTIByZAIbAwUJEswDAAYLCQgHAwIG FQgCCQoLBBYCAwECH In-Reply-To: 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:227214 Archived-At: On 07/09/2018 08:41 PM, Stefan Monnier wrote: > As long as `eq` treats bignums differently from fixnums, I think type-of > should return different values for the two I don't see how this folds into your earlier point about cl-generic's dispatch. I thought the idea of cl-generic was to define a generic function that finds the most specialized method for its arguments. (I'm no expert in cl-generic, so please bear with me if I'm wrong.) If so, why would someone want to specialize a method just for fixnums, as opposed to a method for integers? The basic operations +, -, * etc. aren't specialized for fixnums. Are you anticipating adding specialized variants fixnum-+, fixnum--, fixnum-*, etc., and then having people write methods with all this in mind? Or maybe having the bytecode optimizer use them? If so, I suspect that approach won't be needed for Emacs Lisp. Elisp programs are not typically intended for that sort of microptimization -- otherwise we'd already have operations like integer-+, integer--, integer-*, etc. And the complexity of the differing semantics (fixnum-+ would wrap around, whereas + would not) would probably not be worth the relatively minor performance benefits. If not, then I'm still not following the advantage of having (type-of 5) return something other than 'integer'.