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Message-ID:  <20080910110725.GA3944@irwin.vpn.uni-freiburg.de>
Date:         Wed, 10 Sep 2008 13:07:25 +0200
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From: Heiko Oberdiek <oberdiek@UNI-FREIBURG.DE>
Subject: Re: expl3 variant expansion forms
To: LATEX-L@LISTSERV.UNI-HEIDELBERG.DE
In-Reply-To:  <18631.42022.160484.847483@morse.mittelbach-online.de>
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Status: R

Hello,

On Wed, Sep 10, 2008 at 12:40:38PM +0200, Frank Mittelbach wrote:

>  > When I first read about expl3 years ago, indeed I was naively  
>  > disappointed that the variants weren't constructed "on the fly". But  
>  > that's obviously impossible.
> 
> obviously impossible is perhaps too strong a word,

How do you want to define macros on the fly, being in expandable
contexts (inside \edef, \write, ...)? Or is the use of these macros
forbidden inside expandable contexts?

Next question, how does the "on the fly" process (if such a thing
might exist) decide to define a macro globally or locally?
Local stuff making global isn't a good idea generally,
thus local definitions remain. But this can be ineffective,
if the yet undefined variant is only called inside a separate group.

Yours sincerely
  Heiko <oberdiek@uni-freiburg.de>