From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.1 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id B8E801FD99 for ; Fri, 26 Aug 2016 16:20:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754487AbcHZQUE (ORCPT ); Fri, 26 Aug 2016 12:20:04 -0400 Received: from pb-smtp2.pobox.com ([64.147.108.71]:65064 "EHLO sasl.smtp.pobox.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751321AbcHZQUE (ORCPT ); Fri, 26 Aug 2016 12:20:04 -0400 Received: from sasl.smtp.pobox.com (unknown [127.0.0.1]) by pb-smtp2.pobox.com (Postfix) with ESMTP id BC1ED36C00; Fri, 26 Aug 2016 12:20:02 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type:content-transfer-encoding; s=sasl; bh=7lX3lDA4gnDl geK9Xe2TbzrzzGg=; b=Sa6/R9lY7T+31ASdvngJcD8e2YsCiXJnVu1ZHr6GpRre xtVk+wBpsB2aMZe6O+3Di9bG1sEQxJh2+o61znC7iEeBN5Y4jd5FcmcC2AHvNR73 yZ9lj32GRcWopclxqeQoSGYA1WA8Dj6pVmWj3AyZJ+CNjm7lMAF54FbyF3DBV4E= DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type:content-transfer-encoding; q=dns; s=sasl; b=gxtck4 7347U9hbEWYapebG3QNqsziLzdus51HkmGcAiM425WcFBnHvN8ocGhSDPTKF8k7s pLtexjYGzoven5vk1yjcrfW2GzMzUbKE8eAhQ+aDWm/5Mr8P8gWbkwoqFt8GVAbY LKPxKeVnMOKf37RuZMVphYD6iBrtbmkH5RJv8= Received: from pb-smtp2.nyi.icgroup.com (unknown [127.0.0.1]) by pb-smtp2.pobox.com (Postfix) with ESMTP id 90B4236BFD; Fri, 26 Aug 2016 12:20:02 -0400 (EDT) Received: from pobox.com (unknown [104.132.0.95]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by pb-smtp2.pobox.com (Postfix) with ESMTPSA id 3432C36BF8; Fri, 26 Aug 2016 12:20:01 -0400 (EDT) From: Junio C Hamano To: Jakub =?utf-8?Q?Nar=C4=99bski?= Cc: Philip Oakley , GitList , Marc Branchaud Subject: Re: [PATCH v6 06/12] doc: revisions: single vs multi-parent notation comparison References: <20160811215035.4108-1-philipoakley@iee.org> <20160812234522.7792-1-philipoakley@iee.org> <20160812234522.7792-3-philipoakley@iee.org> <6b37851f-0f2f-0379-c10e-52f7da6b7110@gmail.com> Date: Fri, 26 Aug 2016 09:19:58 -0700 In-Reply-To: <6b37851f-0f2f-0379-c10e-52f7da6b7110@gmail.com> ("Jakub =?utf-8?Q?Nar=C4=99bski=22's?= message of "Fri, 26 Aug 2016 17:30:59 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 X-Pobox-Relay-ID: F057309A-6BA8-11E6-8540-51057B1B28F4-77302942!pb-smtp2.pobox.com Content-Transfer-Encoding: quoted-printable Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Jakub Nar=C4=99bski writes: > W dniu 13.08.2016 o 01:45, Philip Oakley pisze: > >> +'HEAD{caret}2{caret}@', however you cannot say 'HEAD{caret}@{caret}2'= . > > Though I do wonder if it is implementation limitation, or if it is some= thing > inherent in the notation, namely that ^@ and ^! resolve (the = former > at least in general, though not for every ) to more than one revis= ion > specifier. I think that the answer you are giving to the question is the latter, and I tend to agree with you. You could define: A^@ followed by means first expand A^@, and then apply that to each and every one in the resulting set. But some may be merges and while others not. It is unclear what should happen to A^@^2 when one of A's parents has only one parent. In some use cases, it would be convenient if parents of A to which the operation cannot be applied, but in other use cases, it would be convenient if the whole thing caused an error. The notation is not detailed/rich enough to express the distinction.