The correct Unicode≥6.3 way to do this would be with the unicode isolation
characters. I.e. you would wrap each of the columns with <FSI>column
contents<BDI>. Does emacs honor these? Should be easy to test.

Regards,
Dov

On Mon, Dec 4, 2017 at 9:27 PM, Nicolas Goaziou <mail@nicolasgoaziou.fr>
wrote:

> Hello,
>
> Eli Zaretskii <eliz@gnu.org> writes:
>
> >> Date: Wed, 13 Jun 2012 22:26:35 +0300
> >> From: Dov Grobgeld <dov.grobgeld@gmail.com>
> >>
> >> Imagine you have a buffer with the following logical contents (using the
> >> convention that capitals are RTL characters).
> >>
> >> | abcdef | abc |
> >> | ABCDEF | ABC |
> >>
> >> I would like this to be displayed as:
> >>
> >> | abcdef | abc |
> >> | FEDCBA | CBA |
> >>
> >> The problem is that I want to each column of the table to be isolated
> >> (with regards to bidi influence) from other columns in the table. (Of
> >> course we also want to choose the table direction, but that is a
> >> different and solvable issue.) If there is no such separation, which
> >> is the behaviour currently get in emacs HEAD, then the resulting
> >> rendered buffer is:
> >>
> >> | abcdef | abc |
> >> | CBA | FEDCBA |
> >>
> >> Is this even solvable in the current emacs bidi model?
> >
> > Yes, it is.  The solution involves putting segment separators between
> > the table columns.  These could be TAB characters or a display
> > property whose value is (space . :width N) or (space . :align-to COL).
> >
> > Org maintainers, please ask if you need help in fixing this.
>
> *raises a hand*
>
> I'd rather preserve structure of Org documents outside of Emacs. So,
> `:align-to' is not an option.
>
> IIUC, I need to replace the closest space from vertical bars with
>
>   #(" " 0 1 (space :width 1))
>
> This doesn't sound too difficult.
>
> However, could someone provide tests cases so we get it right once and
> for all?
>
> Thank you.
>
> Regards,
>
> --
> Nicolas Goaziou                                                0x80A93738
>