Re: [AUCTeX-devel] Support for expl3

[Sean Allred]

On Apr 3, 2015, at 1:01 AM, David Kastrup <address@hidden> wrote:

Please keep in mind that we need copyright assignments from all authors
of software, and to trace all copyrightable contributions.

I’ll get the forms in post-haste :)

On Apr 3, 2015, at 7:10 AM, Mosè Giordano <address@hidden> wrote:

As David already remembered, you and anyone sensibly helped you must
sign copyright assignments for the style file to be included in
AUCTeX.

The only thing that ‘sensibly helped me’ would be a syntax reminder from Emacs.SE (http://emacs.stackexchange.com/q/10433/2264) in a case where I didn’t understand the docstring in emacs – I’m pretty confident that this is not needing of assignment, given how fundamental it is to Emacs development. (In legalese, it’s public knowledge in the domain.) Otherwise, this is completely my own work.

A minor mode hooked into AUCTeX may be indeed the solution: you
activate it when you want to write expl3 code, turn it off to come
back to write good ol' LaTeX code.

…

How do you think a separate dialect would be helpful?

I received a reply from Frank, who writes:

expl3 is by design fairly lowlevel and we made sure that it does in fact work on top of LaTeX2e, plain TeX and ConTeXt so in that respect it is a dialect of TeX, but it is also different as the other dialiects only partly work on top of the others if at all as they all attempt to provide a full universe not just a foundation - the corresponding full universe would be LaTeX3.

In sum, expl3 is only tangentially related to LaTeX – LaTeX3 will be built with it, but other formats could be as well. In an ideal world, it makes sense for it to be its own mode (with its own bindings and code conventions as laid out in `texdoc l3styleguide`). (For example, brace indentation in standard TeX modes is *not* in agreement with the style guide.)

It comes down to the basic fact that expl3 is a programming language and LaTeX is not (or not supposed to be). Implementing the support as a minor mode, while effective, would not be appropriate (in the lofty sense of what *should* be). There are of course other considerations, like the awkward middle ground `xparse` occupies, but I’m not sure how to fix that. Perhaps a minor mode *would* be the best option, but only if it can be sensibly (i.e. unobtrusively) activated in all of the TeX modes.

I don’t *really* know how to ‘solve’ this problem, but I will be thinking about it throughout the day. I of course welcome any thoughts in the meantime :)

-Sean