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Date:         Wed, 17 Feb 2010 15:05:31 +0000
Reply-To: Mailing list for the LaTeX3 project
              <LATEX-L@listserv.uni-heidelberg.de>
Sender: Mailing list for the LaTeX3 project <LATEX-L@listserv.uni-heidelberg.de>
From: Joseph Wright <joseph.wright@MORNINGSTAR2.CO.UK>
Subject: Re: String module
To: LATEX-L@listserv.uni-heidelberg.de
In-Reply-To:  <4B7C044A.50006@morningstar2.co.uk>
Precedence: list
Status: R

On 17/02/2010 14:59, Joseph Wright wrote:
> On 17/02/2010 14:38, Philipp Stephani wrote:
>> through the input processor, things like spaces and comments are
>> inevitably lost. I thought of something like this:
>
> We had quite a bit of discussion before about verbatim input and xparse.
> At the time the general agreement seemed to be that you can't reliably
> tackle all verbatim items with a generic function. So we decided that it
> was best to stick to code that will work reliably and accept that some
> items (a small percentage of all functions) will need handling "by hand".

I should add that the issue was *if* you could include verbatim input 
using \NewDocumentCommand (as the last argument). The problem is not so 
much getting things right for one argument but dealing with the various 
cases:
  - Several arguments with only the last optional
  - Verbatim w.r.t. only some characters (some can be handled with 
\scantokens, some cannot)
  - Dealing entirely properly with nested functions (and making sure 
that the limitations are clear).
-- 
Joseph Wright