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: Predicate for true lists Date: Sat, 7 Jul 2018 10:14:15 -0700 Organization: UCLA Computer Science Department Message-ID: <17d4bfb6-4c14-901f-716f-4aa50386eb9d@cs.ucla.edu> References: <87fu3vdjjk.fsf@tcd.ie> <87bmcqhhsf.fsf@tcd.ie> <87in6xgtpb.fsf@tcd.ie> <2af892df-26cb-60b2-4fd8-067fcb3d32e9@cs.ucla.edu> <87r2kh9uwx.fsf@tcd.ie> <83h8lcnbxb.fsf@gnu.org> <6fc589d1-2c21-3e9b-be47-b7700f61642d@cs.ucla.edu> <831scflefs.fsf@gnu.org> <5d0d79d3-6291-fbf0-1028-064f86787483@cs.ucla.edu> <837em7jrag.fsf@gnu.org> <87k1q7ytmr.fsf@tcd.ie> <83o9fjhvnk.fsf@gnu.org> <87efgfyomt.fsf@tcd.ie> <83k1q7ht51.fsf@gnu.org> 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 1530983586 12434 195.159.176.226 (7 Jul 2018 17:13:06 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 7 Jul 2018 17:13:06 +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: Eli Zaretskii , "Basil L. Contovounesios" Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Jul 07 19:13:01 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 1fbqlY-00030r-Ea for ged-emacs-devel@m.gmane.org; Sat, 07 Jul 2018 19:13:00 +0200 Original-Received: from localhost ([::1]:34414 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fbqnf-0006gj-GH for ged-emacs-devel@m.gmane.org; Sat, 07 Jul 2018 13:15:11 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:42072) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fbqn1-0006dc-E7 for emacs-devel@gnu.org; Sat, 07 Jul 2018 13:14:32 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fbqn0-00009v-IO for emacs-devel@gnu.org; Sat, 07 Jul 2018 13:14:31 -0400 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:33258) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fbqmw-000077-QI; Sat, 07 Jul 2018 13:14:27 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id ADD16160653; Sat, 7 Jul 2018 10:14:24 -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 3Qf38sa8w8Ht; Sat, 7 Jul 2018 10:14:23 -0700 (PDT) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id C1213160655; Sat, 7 Jul 2018 10:14:23 -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 i72VGVw7C6D6; Sat, 7 Jul 2018 10:14:23 -0700 (PDT) Original-Received: from [192.168.1.9] (unknown [47.154.30.119]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id 6E842160653; Sat, 7 Jul 2018 10:14:23 -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: <83k1q7ht51.fsf@gnu.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:227073 Archived-At: Eli Zaretskii wrote: > LGTM, pushed. I don't see why the change is needed; on the contrary, it is counterproductive. The documentation for "*" doesn't say that "*" signals an error if an argument is not a number or a marker; it says only that its arguments are numbers or markers. This wording means that if we later extend "*" (say, to support multiplication on vectors of numbers), we won't be making an incompatible change. Similarly, the documentation for "length" need not and should not say that it signals an error if its argument is not a sequence; it should merely say that its argument is a sequence. Otherwise, we'll be precluding future changes from being compatible with the existing documentation. If we document that "length" signals an error if its argument is the wrong type, for consistency shouldn't we have similar documentation for "*" and all other functions that signal errors for wrong-type arguments? That sounds like a lot of verbiage to add the manual, and its added length would be a cost that would exceed any benefit. Also, I still don't understand why this documentation change would be helpful for the proposed proper-list-p implementation. As Eli has acknowledged, the proposed implementation does not depend on 'length' signaling an error when given a non-sequence. So why is this documentation change needed even for this particulare case?