From mboxrd@z Thu Jan 1 00:00:00 1970 From: "J. Bruce Fields" Subject: Re: my git problem Date: Tue, 29 Apr 2008 13:15:19 -0400 Message-ID: <20080429171519.GA21310@fieldses.org> References: <20080427112938.4dbe8e2a.akpm@linux-foundation.org> <20080427124454.6a606305.akpm@linux-foundation.org> <20080428114509.240ef4ae.akpm@linux-foundation.org> <20080428120917.dd9f01e8.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Johannes Schindelin , Andrew Morton , git@vger.kernel.org To: Linus Torvalds X-From: git-owner@vger.kernel.org Tue Apr 29 19:16:51 2008 connect(): Connection refused Return-path: Envelope-to: gcvg-git-2@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1JqtRE-0006rR-Ru for gcvg-git-2@gmane.org; Tue, 29 Apr 2008 19:16:21 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754375AbYD2RPY (ORCPT ); Tue, 29 Apr 2008 13:15:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753740AbYD2RPY (ORCPT ); Tue, 29 Apr 2008 13:15:24 -0400 Received: from mail.fieldses.org ([66.93.2.214]:35763 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753596AbYD2RPW (ORCPT ); Tue, 29 Apr 2008 13:15:22 -0400 Received: from bfields by fieldses.org with local (Exim 4.69) (envelope-from ) id 1JqtQF-0005mE-IX; Tue, 29 Apr 2008 13:15:19 -0400 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Mon, Apr 28, 2008 at 12:28:38PM -0700, Linus Torvalds wrote: > > > On Mon, 28 Apr 2008, Johannes Schindelin wrote: > > > > On Mon, 28 Apr 2008, Andrew Morton wrote: > > > > > > That's missing the "logical" bit :) > > > > Heh, you're right. I am too used to Git to think how other people would > > feel about these things... :-) > > No, you are both wrong. > > You're wrong because apparently you never did abstract algebra and set > theory in school. Hmph. I've got a PhD in algebra and still find that choice of operators confusing. (Which may just be further evidence that one can take a lot of classes and still be an idiot.) > If you know math, git actually does the rigth and very much the *logical* > thing. > > So ".." is a simple difference, while "..." is a more complex difference. > > They mean different things for different operation types, but that is > again something a math person takes for granted (ie in algebra, a "+" or > "-" is just a random operation that follows certain rules: "a-b" means one > thing for the set of real numbers, and something *totally* different if > you are talking about set algebra). I suspect one reason the set-difference operator is more commonly written with a backslash than a minus sign is that set difference is different enough from anything else usually called subtraction that most people find it confusing to use the same notation. I can sorta buy the argument that "A...B" means most generally "some kind of difference between the three sets A, A^B, and B", and that in the context of "git diff" it's most sensible to take ordering into account and produce some approximation of a diff between A^B and B. I'd personally have found an entirely separate operator simpler to understand. But perhaps there's only so many keys on the keyboard. --b.