Joseph Wright <[log in to unmask]> writes:

> I'd wondered about implementing \DeclareDocumentCommand so that it
> always did \DeclareDocumentCommandInterface and
> \DeclareDocumentCommandImplementation. However, I'm not sure this really
> works that well. As I've already pointed out, we still rely on the two
> parts having the same number of arguments.  That will fall down if we
> imagine something like:
>
> \section*[short]{long}
>
> versus
>
> <sectiontitle numbered="false",shorttitle="short">
>   long
> </sectiontitle>
>
> or some such XML-like input, at least without an intermediate layer.

I'm not really following this thread -- in particular, I don't
understand exactly what xparse-gellmu might do, much less whether I,
as opposed to someone else, should do it.

But please allow me to point out here that in the case of something
like

    \section*[Translation of \LaTeX{}]{Translation of \LaTeX{}
    to other markup languages}

an XML attribute -- the value of 'shorttitle' above -- cannot contain
markup.  So

  \section*[short]{long}

might better be represented in XML by

<section numbered="false">
<shorttitle>short</shortitle>
<sectiontitle>long</sectiontitle>
...
</section>  *** close tag triggered downstream, e.g., by the magic
                of a full SGML parser


                                -- Bill