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Message-ID:  <4DD0D791.7080201@morningstar2.co.uk>
Date:         Mon, 16 May 2011 08:51:45 +0100
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From: Joseph Wright <joseph.wright@MORNINGSTAR2.CO.UK>
Subject: Re: xparse and space skipping
To: LATEX-L@listserv.uni-heidelberg.de
In-Reply-To:  <730C3860-F74B-453D-87A9-0962DD1699B0@gmail.com>
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Status: R

On 16/05/2011 05:41, Will Robertson wrote:
> Okay, I'm happy with this. We should revert back to space-skipping behaviour; only question is what to do about control symbols? Practically, there are only a handful that you'd expect to see defined to take an optional argument, perhaps \\ and \+ and anything else a user wants to (re-)define.

If we remove the 'varying behaviour' switch (it's a two-line change)
then \\ and \+ behave exactly the same as anything else.

> If we choose space-skipping then we're consistent with 2e; if not we're consistent with amsmath. I tend toward the latter but would also be happy to have \\ as a special case instead and go with the former.

As Frank always reminds us, xparse is exploring LaTeX3 ideas but tied to
LaTeX2e's conventions. So I'd prefer to be consistent with LaTeX2e at
the moment: when we do design syntax for LaTeX3 we may well want to
revise our ideas.
-- 
Joseph Wright