From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Mark H Weaver Newsgroups: gmane.lisp.guile.bugs Subject: bug#17296: Uh, wrong? Date: Tue, 03 Jun 2014 22:55:42 -0400 Message-ID: <87a99tv0wh.fsf@yeeloong.lan> References: <878ur25thj.fsf@yeeloong.lan> <87wqcx99zk.fsf@fencepost.gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1401850646 4073 80.91.229.3 (4 Jun 2014 02:57:26 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 4 Jun 2014 02:57:26 +0000 (UTC) Cc: 17296@debbugs.gnu.org To: David Kastrup Original-X-From: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Wed Jun 04 04:57:18 2014 Return-path: Envelope-to: guile-bugs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Ws1O9-00066v-Gs for guile-bugs@m.gmane.org; Wed, 04 Jun 2014 04:57:17 +0200 Original-Received: from localhost ([::1]:56953 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ws1O9-0007ge-81 for guile-bugs@m.gmane.org; Tue, 03 Jun 2014 22:57:17 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:53271) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ws1O0-0007fh-MP for bug-guile@gnu.org; Tue, 03 Jun 2014 22:57:14 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ws1Nu-0008KM-Oo for bug-guile@gnu.org; Tue, 03 Jun 2014 22:57:08 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:44004) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ws1Nu-0008KH-Lg for bug-guile@gnu.org; Tue, 03 Jun 2014 22:57:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1Ws1Nu-00068l-41 for bug-guile@gnu.org; Tue, 03 Jun 2014 22:57:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Mark H Weaver Original-Sender: "Debbugs-submit" Resent-CC: bug-guile@gnu.org Resent-Date: Wed, 04 Jun 2014 02:57:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 17296 X-GNU-PR-Package: guile X-GNU-PR-Keywords: patch Original-Received: via spool by 17296-submit@debbugs.gnu.org id=B17296.140185057123491 (code B ref 17296); Wed, 04 Jun 2014 02:57:01 +0000 Original-Received: (at 17296) by debbugs.gnu.org; 4 Jun 2014 02:56:11 +0000 Original-Received: from localhost ([127.0.0.1]:42880 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1Ws1N4-00066o-3n for submit@debbugs.gnu.org; Tue, 03 Jun 2014 22:56:10 -0400 Original-Received: from world.peace.net ([96.39.62.75]:50633 ident=hope6) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1Ws1Mv-000663-8H for 17296@debbugs.gnu.org; Tue, 03 Jun 2014 22:56:07 -0400 Original-Received: from 209-6-91-212.c3-0.smr-ubr1.sbo-smr.ma.cable.rcn.com ([209.6.91.212] helo=yeeloong.lan) by world.peace.net with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.72) (envelope-from ) id 1Ws1Mo-0000sE-Cr; Tue, 03 Jun 2014 22:55:54 -0400 In-Reply-To: <87wqcx99zk.fsf@fencepost.gnu.org> (David Kastrup's message of "Tue, 03 Jun 2014 19:30:23 +0200") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 140.186.70.43 X-BeenThere: bug-guile@gnu.org List-Id: "Bug reports for GUILE, GNU's Ubiquitous Extension Language" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Original-Sender: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.bugs:7486 Archived-At: David Kastrup writes: > So the behavior for length+ on a dotted list is strictly unspecified. > It is not even stated "it is an error". Actually, it is. At the end of the section that defines the "types" such a "clist" and "flist", it states: It is an error to pass a circular or dotted list to a procedure not defined to accept such an argument. While it is true that we are not required to signal an error, I'm wary extending 'length+' in this way. It also effectively extends 'map' and 'for-each' to support things like (map + '() 'foo), and thus potentially affects many other procedures both inside and outside of Guile that use 'map' and 'for-each'. Once we've done this, users are likely to grow dependent on it and we can never go back. > At any rate, what I am getting at is that I was going to submit the > following patch as a part of a series fixing other bugs, bugs that I > need a working "get the length of a dotted list" operator for. We don't > have any such operator in GUILE, and that's awkward. It might be helpful to add such a procedure, but I don't think 'length+' should be it. Regards, Mark