From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Jim Ottaway Newsgroups: gmane.emacs.help Subject: Re: puzzling byte-compile-file message: `=' called for effect Date: Tue, 15 Nov 2005 17:09:35 +0000 Message-ID: <87lkzpltww.fsf@lse.ac.uk> References: NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: sea.gmane.org 1132074647 9451 80.91.229.2 (15 Nov 2005 17:10:47 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Tue, 15 Nov 2005 17:10:47 +0000 (UTC) Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Tue Nov 15 18:10:46 2005 Return-path: Original-Received: from lists.gnu.org ([199.232.76.165]) by ciao.gmane.org with esmtp (Exim 4.43) id 1Ec4K2-0007ri-DN for geh-help-gnu-emacs@m.gmane.org; Tue, 15 Nov 2005 18:10:18 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Ec4K1-0007DV-Rg for geh-help-gnu-emacs@m.gmane.org; Tue, 15 Nov 2005 12:10:17 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Ec4JY-0007Bw-Sy for help-gnu-emacs@gnu.org; Tue, 15 Nov 2005 12:09:48 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Ec4JX-00079e-5C for help-gnu-emacs@gnu.org; Tue, 15 Nov 2005 12:09:48 -0500 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Ec4JW-00079L-WF for help-gnu-emacs@gnu.org; Tue, 15 Nov 2005 12:09:47 -0500 Original-Received: from [194.247.47.231] (helo=mailout.zetnet.co.uk) by monty-python.gnu.org with esmtp (TLS-1.0:RSA_AES_128_CBC_SHA:16) (Exim 4.34) id 1Ec4JW-00004u-HN for help-gnu-emacs@gnu.org; Tue, 15 Nov 2005 12:09:46 -0500 Original-Received: from irwell.zetnet.co.uk ([194.247.47.48] helo=zetnet.co.uk) by mailout.zetnet.co.uk with esmtp (Exim 4.50) id 1Ec4JS-0006Ok-QE for help-gnu-emacs@gnu.org; Tue, 15 Nov 2005 17:09:42 +0000 Original-Received: from runcible (53-186.adsl.zetnet.co.uk [194.247.53.186]) by zetnet.co.uk (8.13.4/8.13.4/Debian-3) with ESMTP id jAFH9g86003665 for ; Tue, 15 Nov 2005 17:09:42 GMT Original-Received: from jeho by runcible with local (Exim 4.50) id 1Ec4JL-00058X-MG for help-gnu-emacs@gnu.org; Tue, 15 Nov 2005 17:09:35 +0000 Original-To: help-gnu-emacs@gnu.org In-Reply-To: (Drew Adams's message of "Tue, 15 Nov 2005 08:39:13 -0800") User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.0.50 (gnu/linux) X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:31071 Archived-At: >>>>> Drew Adams writes: > The term "for effect" is correct here, but I don't think it is as clear as > it could be. The compiler is suggesting that, if the `=' expression is > useful, it must be useful because of side effects that occur during its > evaluation. > I think the compiler should explicitly say that the resulting _value_ of the > `=' expression is not used. It might also say that the `=' expression may be > useful for its side effects (or side effects of its subexpressions), but the > resulting value has no effect on the overall code. At a minimum, the word > "side" should be added to "effect". Yes, I agree. I was so puzzled by the elliptical message that I missed the obvious error in my code. > The message might better say: > "Warning: `=' return value ignored. Is the expression useful > for its side effects?" Something like that, I agree, even simply "`=' called for side effect alone". > Ccing emacs-devel, as I think the message should be clarified > somehow. Me too. Regards, -- Jim Ottaway