Received: from mx0.gmx.net (mx0.gmx.net [213.165.64.100]) by h1439878.stratoserver.net (8.14.2/8.14.2/Debian-2build1) with SMTP id p05IWk59025752 for ; Wed, 5 Jan 2011 19:32:48 +0100 Received: (qmail 4212 invoked by alias); 5 Jan 2011 18:32:41 -0000 Delivered-To: GMX delivery to rainer.schoepf@gmx.net Received: (qmail invoked by alias); 05 Jan 2011 18:32:40 -0000 Received: from relay.uni-heidelberg.de (EHLO relay.uni-heidelberg.de) [129.206.100.212] by mx0.gmx.net (mx008) with SMTP; 05 Jan 2011 19:32:40 +0100 Received: from listserv.uni-heidelberg.de (listserv.uni-heidelberg.de [129.206.100.94]) by relay.uni-heidelberg.de (8.14.1/8.14.1) with ESMTP id p05IUgPc005577 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 5 Jan 2011 19:30:42 +0100 Received: from listserv.uni-heidelberg.de (localhost.localdomain [127.0.0.1]) by listserv.uni-heidelberg.de (8.13.1/8.13.1) with ESMTP id p05HVxZQ002376; Wed, 5 Jan 2011 19:30:31 +0100 Received: by LISTSERV.UNI-HEIDELBERG.DE (LISTSERV-TCP/IP release 16.0) with spool id 810259 for LATEX-L@LISTSERV.UNI-HEIDELBERG.DE; Wed, 5 Jan 2011 19:30:31 +0100 Received: from relay.uni-heidelberg.de (relay.uni-heidelberg.de [129.206.100.212]) by listserv.uni-heidelberg.de (8.13.1/8.13.1) with ESMTP id p05IUVJs002451 for ; Wed, 5 Jan 2011 19:30:31 +0100 Received: from moutng.kundenserver.de (moutng.kundenserver.de [212.227.17.9]) by relay.uni-heidelberg.de (8.14.1/8.14.1) with ESMTP id p05IUQkD005033 for ; Wed, 5 Jan 2011 19:30:30 +0100 Received: from morse.mittelbach-online.de (p3EE3E037.dip.t-dialin.net [62.227.224.55]) by mrelayeu.kundenserver.de (node=mrbap1) with ESMTP (Nemesis) id 0MZfXq-1PtrfI0rhG-00LpIJ; Wed, 05 Jan 2011 19:30:26 +0100 Received: by morse.mittelbach-online.de (Postfix, from userid 501) id 3D90374DC4; Wed, 5 Jan 2011 19:30:22 +0100 (CET) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit References: <4D22486F.5000506@morningstar2.co.uk> X-Mailer: VM 7.19 under Emacs 21.3.1 X-Provags-ID: V02:K0:cwcGo8lVqjq02dlKT6wJdjZvthyaNlX4yXdN22pwVft XCYsz/LVJxbz3UnFAXlnGFpXVCybY4zNVbCWEjI/ZaznKfbZgX Ep7KkGYxRT7wEmQXLmPQoqu1IbQXby1f9jvCa1DUeftP5vERZz 1lhajHmoJYB/OwEKRIy7pf6oi8dFwKwKEYDXkEadZDUerKX2m3 i7llww59iu3mZOYW9/M5A== X-Spam-Whitelist-Provider: Message-ID: <19748.47294.93978.108113@morse.mittelbach-online.de> Date: Wed, 5 Jan 2011 19:30:22 +0100 Reply-To: Mailing list for the LaTeX3 project Sender: Mailing list for the LaTeX3 project From: Frank Mittelbach Subject: Re: \box_if_empty:N(TF) To: LATEX-L@listserv.uni-heidelberg.de In-Reply-To: <4D22486F.5000506@morningstar2.co.uk> Precedence: list List-Help: , List-Unsubscribe: List-Subscribe: List-Owner: List-Archive: X-GMX-Antispam: 0 (Mail was not recognized as spam); Detail=5D7Q89H36p77e5KAPs1l6v/Sb97LojnDtMgfETrECMLUO9erHzOJe7j3G660N4yBY6XHH YPYtmQj6mbYUTZ3LnaFANLWrKE7/wIDhnv+VrW0hxOapLRUwuY9oBqo5h+Dh9B42XlFTMTKlXDju GaV8Q==V1; X-Resent-By: Forwarder X-Resent-For: rainer.schoepf@gmx.net X-Resent-To: rainer@rainer-schoepf.de Status: R X-Status: X-Keywords: X-UID: 6521 Joseph Wright writes: > Hello all, > > Working on the galley (see the latest SVN checkin), I find that > \box_if_empty:NTF is misleading. The test is for a void box, not an > empty one: > > \box_new:N \l_my_box > \hbox_set:Nn \l_my_box {} > \box_if_empty:NTF \l_my_box { NOPE } { OOPS } > > I think it should be \box_if_void:NTF - any objections? well, I think we can clearly state that the l3box module is far from being what it should be, both in the sense of being incomplete as well as in the sense of being partly wrong or containing badly named commands. The above probably being an example of the latter. However, I'm not sure that "void" is the best word either. Ok, there is the meaning "voiding something" ie making it invalid and to some extense that is what a void box register is: you can't do most of the operations on it. But there is also the meaning of void that is closer to empty and that is what I think makes both void and empty a bad choice as there is clearly also something like an empty hbox (\null) or \vbox{} ie a box that has no content but is set in terms of what input it could have had. maybe \box_if_unset:NTF is closer to its meaning. A similar question goes for \box_use_clear:N ... that boxed isn't "cleared" it is unset too afterwards. Heiko's test for emptyness is testing for something quite different, isn't it? Not sure there is an application for it, but perhaps there is (but probably only if you provide other complex box manipulation commands as well) frank