Re: [emacs-bidi] visual-mode, LyX

[Eli Zaretskii]

On Thu, 25 Jan 2001, Uwe Brauer wrote:

> The other comment I would like to make is based on my
> experience with LyX (for those who don't know LyX is more or
> less a WYSIWYG interface for latex.)
> LyX has BIDI support and also support Niqud, using MSDOS
> truefonts and a truefont Xserver like xfstt. 
> Is there any attempt to include such a feature for emacs-21?

I'm sorry, I cannot really comment on this because I don't really
understand what feature(s) are you talking about.  In particular, what
do MS-DOS fonts have to do with X, and why is it important to support
xfstt.

The current work (if I may call discussions and testing of ideas
``work'') on the bidi support in Emacs faces fundamental problems of
how to add logical to visual conversion to the Emacs display engine.
We are way far from considering issues like fonts or Hebrew
diacriticals, which are user-level features.

> Another minor point: the BIDI support of LyX is still very
> premature (in fact only one person is coding), so for
> example if a paragraphs starts with say Hebrew and one
> switches to English, the cursor just stands idle and the
> characters are 'floating out'. The same is true vice versa
> for a paragraph starting with English and one switches to
> Hebrew. To me surprise it is not that inconvenient as it
> sounds.

It is one of two possible behaviors of the cursor in these cases.  The
other possible behavior is like this (`_' indicates where the cursor
is):

      abcde_

      abcde A_

      abcde BA_

      abcde CBA_

etc., you get the point.

> This attempt may be worth copying it for the very first 
> steps in BIDI support for emacs-21.

I'm not sure what are you suggesting.  If you mean that we should copy
the display code from LyX, I'd doubt if it will fit into Emacs (but
I'll certainly look, unless someone who knows can describe it).  Do you 
have a URL for LyX?