Re: Re: Handling invisible text in bidirectional display

[Eli Zaretskii <eliz@gnu.org>]

> From: David Kastrup <dak@gnu.org>
> Date: Sun, 17 Jan 2010 21:17:35 +0100
> Cc: emacs-devel@gnu.org
> 
> >   3*(54)DCBA
> >
> > which I think is less surprising.
> 
> I disagree, because there is no reason for 5 and 4 to switch their order
> anymore.

Well, then we'll have to disagree.

> There also is a difference between invisibility and display properties
> here: if there is a display property on a letter "x", it is hard to see
> why several consecutive images should be reordered to be L->R.  Of
> course, one should argue that in the presence of L->R, people should
> take care to use the right "shadowed" character to match the intended
> left/rightness of the image.  But I think that is not really sane.  If
> we want display property material to have an explicit direction, it
> should be set with properties, not by some magic derivation from the
> underlying invisible text.

I don't understand the use-case, and without it this reads like a
charade (what "x"? which "shadowed" characters? what images?).  Please
show a complete example, then I'll be able to reason about it.