From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: npostavs@users.sourceforge.net Newsgroups: gmane.emacs.bugs Subject: bug#24353: 25.1.1: looking-back wrong info Date: Fri, 02 Sep 2016 20:14:36 -0400 Message-ID: <87oa45on4j.fsf@users.sourceforge.net> References: <83lgzael08.fsf@gnu.org> <83k2euehyc.fsf@gnu.org> <1a485a01-87cd-db03-4a0b-2e9033754c46@yandex.ru> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1472861723 19080 195.159.176.226 (3 Sep 2016 00:15:23 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 3 Sep 2016 00:15:23 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) Cc: 24353@debbugs.gnu.org, Dmitry Gutov To: Drew Adams Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Sat Sep 03 02:15:19 2016 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1bfyc9-0004Ky-Af for geb-bug-gnu-emacs@m.gmane.org; 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a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:sender:from:to:cc:subject:references:date :in-reply-to:message-id:user-agent:mime-version; bh=jAF0RQ3uftOKW/8I4HDpS9e3BjWpWiD4YBW6Bz6V11w=; b=hkM7SuZUxbH035jZxNSOCcJV/Z2Rg/lOAnAevQ2qCyT/iSEg/sQPSK1T+fDCF//bK9 itKEKJMCbXa+lKfGyJxmfF/vTmsaMGj/SJz86DDchMytXsxnJbznH+Rgss1RlEhftKdg ho6I+sn1HQ/B5fKoAFf+seRIIhy5AJkV95EZSqprQk7VxScxOrpWM5x+rHhnsdVRCYrM KkizZqJcueU0WQbNFHHWU3rof4u3lQi9CN6qxHEJiy0b2C3ybY2j1nIpDLOcmpzjSdlu 5bfu5gLICe9iCFxgz3oixkl7UhoU6a+E5frDslM4HyUZg4GaXhhXgbPk2frkX1TuLBgL u5HA== X-Gm-Message-State: AE9vXwNulZfdBfJuNopYqxU+H/oCuvA+T5pD1xSSMXJxs2b/bKrgfJzw87wQkkzRjdUeMA== X-Received: by 10.36.20.9 with SMTP id 9mr7905031itg.24.1472861656055; Fri, 02 Sep 2016 17:14:16 -0700 (PDT) Original-Received: from zony ([45.2.7.130]) by smtp.googlemail.com with ESMTPSA id d13sm711380ioj.30.2016.09.02.17.14.15 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 02 Sep 2016 17:14:15 -0700 (PDT) In-Reply-To: (Drew Adams's message of "Fri, 2 Sep 2016 16:59:30 -0700 (PDT)") X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 208.118.235.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.org gmane.emacs.bugs:122872 Archived-At: Drew Adams writes: > > The right way to _encourage_ programmers to use it is to > tell them precisely that: "Using LIMIT is recommended - it > typically results in faster code." > > Or "strongly recommended". Or "You're nuts if you omit LIMIT!" > Or whatever other positive or negative encouragement you think > might be most effective and appropriate. > > Telling them nothing about this and, instead, just showing a > false signature, does NOT help them. So something like this: diff --git i/lisp/subr.el w/lisp/subr.el index e9e19d3..4d1267a 100644 --- i/lisp/subr.el +++ w/lisp/subr.el @@ -3533,7 +3533,10 @@ looking-back LIMIT. As a general recommendation, try to avoid using `looking-back' -wherever possible, since it is slow." +wherever possible, since it is slow. + +For backwards compatibility LIMIT may be omitted, but this usage +is deprecated." (declare (advertised-calling-convention (regexp limit &optional greedy) "25.1")) (let ((start (point)) >> > It should be a no-no to just change the advertized >> > signature of a function, without changing the actual >> > signature (code) and without otherwise changing the doc. >> >> You have some point there, but mentioning the last argument in the >> docstring would be rather awkward, considering it's absent in the >> advertised signature. The number (and names) of arguments have not been changed. > > 2. We removed this sentence, which was the only suggestion > related to performance: > > "As a general recommendation, try to avoid using > `looking-back' wherever possible, since it is slow." Not sure which version you're looking at, but that sentence is still present on both emacs-25 and master branches.