Re: [emacs-bidi] Suboptimal display-reordering in minibuffer

[Amit Aronovitch]

On Tue, Jun 29, 2010 at 8:34 PM, Eli Zaretskii <address@hidden> wrote:

> Date: Tue, 29 Jun 2010 17:26:56 +0900
> From: "Martin J. Dürst" <address@hidden>
> CC: Amit Aronovitch <address@hidden>, address@hidden

>
> > Emacs does not yet handle HTML, XML, and other similar markup formats
> > with bidi text.  Before we add such support, we need to design it.
> > UAX#9 is of no help here; we need to come up with our own solution,
> > preferably one that is based on existing Emacs features.  This is a
> > significant job, so I put it aside for now.
>
> I think I have mentioned this before, but we have been doing some work
> in the area of rendering HTML/XML source with bidi text. Please see
> http://www.sw.it.aoyama.ac.jp/2008/pub/IUC32-bidi/ and the links from
> there. (it still has quite a few problems, mostly related to editing Web
> pages and _javascript_,...)
>
> It also looks like we might get around to work on transposing our
> solutions to Emacs this year. It's too early to promise anything, but
> we'll try our best. And we will certainly be glad to get help and advice
> from this list.

Thanks.  You did mention this before, and I've read those pages.

This is new to me. Thanks for mentioning this again :-)
 

However, it is difficult to judge their applicability to Emacs,
because virtually nothing is said regarding the implementation, except
that it "uses overlays".

So it would be good to discuss your suggested solution for Emacs, to
make sure that it fits.  Please note that the "emacs-bidi" you used
for your work is radically different in the way it implements bidi
reordering from what was eventually designed and implemented in the
current Emacs development sources.  So what worked with "emacs-bidi"
will not necessarily work well with the current mainline code.

> The problem of properly (or let's say decently or reasonably) displaying
> (e.g. C) source code with bidi characters is in my estimation quite a
> bit simpler than the problem for HTML or XML.

So maybe we should start with a simpler problem ;-)

Please have a look at the following draft Israeli standard (by SII): http://db.tt/rc21Gd
(note that this is a draft that is being revised, it did not get to public review stage yet, so I will not keep this link up for long, but any comments are welcome even at this stage).
It tries to both define general guidelines and describe specific examples for various syntaxes, from simple filenames, to computer languages and XML documents. (It handles display alone. UI stuff like cursor movement is covered by a different standard, which is planned to be revised in 2011, I think).

The important thing is to establish whether we need some
infrastructure in Emacs that is currently missing, because that would
need to be coded first, before any user-visible progress can be made.

I believe that the required infrastructure has a lot in common with the coloring (font-lock) system. The basic requirement is recognizing syntactical elements (such as identifiers, strings and comments).
I'd appreciate your input on this document.

    AA