From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Predicate for true lists Date: Sat, 07 Jul 2018 09:58:47 +0300 Message-ID: <831scflefs.fsf@gnu.org> 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> NNTP-Posting-Host: blaine.gmane.org X-Trace: blaine.gmane.org 1530946642 478 195.159.176.226 (7 Jul 2018 06:57:22 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 7 Jul 2018 06:57:22 +0000 (UTC) Cc: contovob@tcd.ie, emacs-devel@gnu.org To: Paul Eggert Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Jul 07 08:57:17 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 1fbh9f-0008Nq-6Z for ged-emacs-devel@m.gmane.org; Sat, 07 Jul 2018 08:57:15 +0200 Original-Received: from localhost ([::1]:60796 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fbhBk-0006sl-SQ for ged-emacs-devel@m.gmane.org; Sat, 07 Jul 2018 02:59:24 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:38152) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fbhB9-0006sW-KO for emacs-devel@gnu.org; Sat, 07 Jul 2018 02:58:48 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fbhB6-0007JR-Di for emacs-devel@gnu.org; Sat, 07 Jul 2018 02:58:47 -0400 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:48996) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fbhB6-0007JK-9p; Sat, 07 Jul 2018 02:58:44 -0400 Original-Received: from [176.228.60.248] (port=3942 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1fbhB5-0005b1-Pa; Sat, 07 Jul 2018 02:58:44 -0400 In-reply-to: <6fc589d1-2c21-3e9b-be47-b7700f61642d@cs.ucla.edu> (message from Paul Eggert on Fri, 6 Jul 2018 11:04:55 -0700) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2001:4830:134:3::e 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:227034 Archived-At: > Cc: emacs-devel@gnu.org > From: Paul Eggert > Date: Fri, 6 Jul 2018 11:04:55 -0700 > > Eli Zaretskii wrote: > > Do we really want this usage of the function as a predicate? I find > > this slightly unnatural, > > Me too, but we haven't come up with a better function semantics, so let's just > live with them. I don't care whether the function is called proper-list-length > or proper-list-p. (As Drew mentioned, we could have both names.) I'd prefer proper-list-p, as this is going to be by far the most frequent use of the function, as evidenced by the patch. > > and also not future-proof enough, because you > > rely on the checks 'length' does internally. > > I see now that those checks of 'length' were documented incorrectly, so I > installed the attached documentation fix into the emacs-26 branch. It should be > OK to rely on these checks (after all, they're documented correctly now :-). Thanks, but the documentation still doesn't say that 'length' signals an error for anything that is not a sequence, which is what proper-list-p is relying on.