From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Andre Spiegel Newsgroups: gmane.emacs.devel Subject: Re: Limitations of Emacs' vc when using modern backends Date: Thu, 15 Dec 2005 09:37:44 -0500 Message-ID: <1134657464.23436.74.camel@localhost> References: <7i8xunt9ub.fsf@lanthane.pps.jussieu.fr> NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit X-Trace: sea.gmane.org 1134666861 26708 80.91.229.2 (15 Dec 2005 17:14:21 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Thu, 15 Dec 2005 17:14:21 +0000 (UTC) Cc: rms@gnu.org, Stefan Monnier , emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Dec 15 18:14:18 2005 Return-path: Original-Received: from lists.gnu.org ([199.232.76.165]) by ciao.gmane.org with esmtp (Exim 4.43) id 1EmwdI-0002sy-6V for ged-emacs-devel@m.gmane.org; Thu, 15 Dec 2005 18:11:08 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Emwdw-0007Jk-4M for ged-emacs-devel@m.gmane.org; Thu, 15 Dec 2005 12:11:48 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1EmuH9-0004OP-G2 for emacs-devel@gnu.org; Thu, 15 Dec 2005 09:40:07 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1EmuGx-0004KI-NV for emacs-devel@gnu.org; Thu, 15 Dec 2005 09:40:03 -0500 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1EmuGv-0004Jf-U1 for emacs-devel@gnu.org; Thu, 15 Dec 2005 09:39:54 -0500 Original-Received: from [193.113.160.41] (helo=mail.o2.co.uk) by monty-python.gnu.org with esmtp (Exim 4.34) id 1EmuJ5-0002Oj-Lr; Thu, 15 Dec 2005 09:42:08 -0500 Original-Received: from [216.255.168.215] (216.255.168.215) by mail.o2.co.uk (7.0.045) id 436B9C6C0053000E; Thu, 15 Dec 2005 14:38:56 +0000 Original-To: Juliusz Chroboczek In-Reply-To: <7i8xunt9ub.fsf@lanthane.pps.jussieu.fr> X-Mailer: Evolution 2.2.3 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:47789 Archived-At: Juliusz, [ RMS, please see comments at the end ] > 1. It should be possible for a backend to override > vc-previous-version. Agreed, it surely has to be backend-dependent. > (2) CVS versions files, while modern systems version trees; the effect > is that the correct ``previous version'' depends on the file name. That's also reasonable. Out of curiosity, I wonder whether that is really the only place you came across where "versioning files" and "versioning trees" conflict? I would expect that there are more places, and vc-previous-version sounds like a pretty inocuous, although no doubt relevant spot. > I believe that the functionality of vc-darcs-rev-to-hash (getting a > canonical revision identifier for a given revision identifier) should > be moved into vc itself, and called whenever vc gets a revision from > the user. The default implementation would just be the identity, but > it should be possible for a backend to override it. Although the hash identifier seems rather specific to Darcs, I can see how this could be useful for other backends -- you can also refer to CVS and RCS revisions symbolically (both branches and individual revisions), and it would be nice to canonicalize those too (turning them into real version numbers), if only optionally. If this is done, auto-completion for symbolic revision names would be a logical next step (but certainly not now). So your suggested changes seem very low-impact to me (they would be trivial from the perspective of other backends). I don't see a reason not to make them right now, but perhaps RMS should have the final word on this. Richard?