[XeTeX] New version of xetex

[David Carlisle]

On 29 July 2014 10:55, Khaled Hosny <khaledhosny at eglug.org> wrote:
> On Mon, Jul 28, 2014 at 07:25:39PM +0200, Khaled Hosny wrote:
>> On Mon, Jul 28, 2014 at 10:24:39PM +1000, Vafa Khalighi wrote:
>> > >
>> > > Thanks, fixed.
>> > >
>> > >
>> > Thanks. I will try that. I know that in the new algorithm, \beginR,
>> > \beginL, \endR, and \endL are also allowed in math mode. But consider this
>> > minimal document
>> >
>> > \documentclass{article}
>> > \begin{document}
>> > \hbox{\beginR\vbox{%
>> > $$1+2=3$$
>> > }\endR}
>> > \end{document}
>> >
>> > The display math will be typeset RTL. Is there any switch that allows this
>> > to not happen? in etex, display math was always LTR but if there is some
>> > switch to turn this on/off, it would be great.
>>
>> So far there is not, but I'm still figuring what is the best option
>> here, may be a new primitive, say, \XeTeXmathdirection, with the values
>> 0 meaning math is always LTR (the default) and 1 meaning math respects
>> the surrounding text direction?
>
> Looking more closely, it seems I misidentified the issue. TeX-XeT resets
> the direction before inline and display math, so math is always LTR, but
> it seems that there is a bug that prevents this from happening in your
> example, I'll check that.
>
> In XeTeX we additionally allow the direction primitives in math mode so
> that one can manually override the default. I still think
> \XeTeXmathdirection primitive is needed to allow for document wide RTL
> math, but this is a different issue.
>
> Regards,
> Khaled
>

If you are looking at extending xetex's RTL support is there any
chance of addressing RTL tables (as affects for example longtable in
the other thread)?
as the nodes can only go in hmode there is no good place to put them
to affect the ordering of columns in an halign.

David