Re: bidi-display-reordering is now non-nil by default

[Eli Zaretskii <eliz@gnu.org>]

> From: David Kastrup <dak@gnu.org>
> Date: Sun, 31 Jul 2011 16:26:12 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> From: David Kastrup <dak@gnu.org>
> >> Date: Sun, 31 Jul 2011 15:54:01 +0200
> >> 
> >> I repeat: we are currently talking about the default of
> >> bidi-paragraph-direction which Eli argues should be nil in all modes
> >> (not just text-mode derived ones) that don't explicitly override it.
> >
> > I never said that.  I just mentioned that as a possible solution.
> 
> There were explicit plans discussed for making a buffer-name list where
> a nil default would get overriden.

That was one idea, yes.  It still is, and IMO should be considered.

> I consider that approach a non-starter.  Or rather a non-finisher.

Look, you only learned about this issue this morning.  I don't think
it's wise to make up our minds about the best solution after so little
thought.  I think we need more data points and more rational
discussions of the various aspects of this.  I would also like to hear
at least one other serious user of R2L scripts.  This is an important
usability issue, it shouldn't be decided on a knee-jerk basis.

> >> There are many modes in Emacs that are doing some sort of tabular
> >> display, and flipping some vertical areas of the display horizontally
> >> around depending on the directionality of the first explicit character
> >> is going to make it _harder_, not easier for people trying to work with
> >> bidi content to get sensible results.
> >
> > Which modes are you talking about, specifically?
> 
> dired, buffer-list, ses

Dired is not affected, as the first character is always strong L.
Buffer-list already sets bidi-paragraph-direction to left-to-right.
As for SES Mode, I couldn't get it to display R2L characters, probably
because I don't know anything about SES, and couldn't find any docs.
(It looks like it uses symbols instead of strings?)  If someone can
show a recipe for doing that, I will look into it.

> lots of things.  Basically almost everything
> that one likes using fixed-width fonts for (or which uses alignment
> properties in order to still look good with variable-pitch fonts) would
> likely get awkward with nil bidi-paragraph-direction.

I think we should raise and discuss specific examples.  There's no
ideology here, just pragmatic choices, so we should study several data
points to see which alternative is better.