From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Sergei Organov Newsgroups: gmane.emacs.help Subject: Re: Problem advising nreverse. Date: Tue, 15 Dec 2009 15:02:39 +0300 Message-ID: References: <87skbg8jww.fsf@galatea.local> <87bpi1n1z7.fsf@galatea.local> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1260879394 5165 80.91.229.12 (15 Dec 2009 12:16:34 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 15 Dec 2009 12:16:34 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Tue Dec 15 13:16:27 2009 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1NKWKF-0006hx-LK for geh-help-gnu-emacs@m.gmane.org; Tue, 15 Dec 2009 13:16:24 +0100 Original-Received: from localhost ([127.0.0.1]:52720 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NKWKC-00076Y-Vz for geh-help-gnu-emacs@m.gmane.org; Tue, 15 Dec 2009 07:16:21 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NKW7Z-0005wh-KC for help-gnu-emacs@gnu.org; Tue, 15 Dec 2009 07:03:17 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NKW7U-0005tM-Ve for help-gnu-emacs@gnu.org; Tue, 15 Dec 2009 07:03:17 -0500 Original-Received: from [199.232.76.173] (port=37639 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NKW7U-0005tA-P5 for help-gnu-emacs@gnu.org; Tue, 15 Dec 2009 07:03:12 -0500 Original-Received: from lo.gmane.org ([80.91.229.12]:55414) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1NKW7U-0000Kv-4w for help-gnu-emacs@gnu.org; Tue, 15 Dec 2009 07:03:12 -0500 Original-Received: from list by lo.gmane.org with local (Exim 4.50) id 1NKW7N-0001rk-5O for help-gnu-emacs@gnu.org; Tue, 15 Dec 2009 13:03:05 +0100 Original-Received: from 89.175.180.246 ([89.175.180.246]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 15 Dec 2009 13:03:05 +0100 Original-Received: from osv by 89.175.180.246 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 15 Dec 2009 13:03:05 +0100 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 58 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 89.175.180.246 User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6 (newer, 3) 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:70657 Archived-At: Kevin Rodgers writes: > [I'm responding to this message, because subsequently the thread spun out of > control beyond my comprehension.] > > Sergei Organov wrote: >> pjb@informatimago.com (Pascal J. Bourguignon) writes: > ... >>> Redefining nreverse and reloading the ewoc-collect function would help >>> as indicated... >> >> Yeah, but: >> >> 1. I don't really want `nreverse' to be always redefined. > > If you know the bug is in ewoc, you don't want nreverse redefined ever. > >> 2. I don't know how to reload `ewoc-collect' (from elisp) provided it's >> already byte-compiled. > > Put the new defun in a file and explicitly reload it. Copy-paste the original and fix that? This has its own drawbacks. Think what will happen when new version of the package with incompatible function appears. >> Here what I've actually originally tried (that didn't work): >> >> (defadvice ewoc-collect (around fix-ewoc-collect activate) >> "Fix buggy `ewoc-collect' by reversing its result provided it >> was altered by `nreverse'." >> (let ((last-nreverse-result)) >> (unwind-protect >> (progn >> (defadvice nreverse (after notice-nreverse activate) >> (setq last-nreverse-result ad-return-value)) >> ad-do-it) > > ad-do-it is not a variable: it is a form that can only be meaningfully > referenced *within* a defadvice form. But it *is* within 'fix-ewoc-collect' defadvice form (look at top-level). > >> (ad-unadvise 'nreverse)) >> (if (eq last-nreverse-result ad-return-value) >> (setq ad-return-value (nreverse ad-return-value))))) > > I don't understand: How can you determine whether any value "was > altered by nreverse"? That is not Lispish thinking. Yeah, probably it is not Lispish. Another option was to make 'nreverse' a no-op for duration of 'ewoc-collect' call, but that didn't work either, apparently due to the same reason defadvice of nreverse doesn't work. -- Sergei.