On Sat, Apr 04, 2009 at 12:35:30PM +0200, Hans Hagen wrote:
> Khaled Hosny wrote:
> indeed, so we're looking into it now (an dlet's forget about the  
> page/bodydir for the moment)
>
> since textdir and pardir go hand-in-hand i suggest the following
>
> \setuplayout[direction=r2l]    % also influences general layout issues

I assume that will mirror all layout elements like double sided page
numbering, right and left pages etc. right?

> \setupalign [r2l]              % textdir and pardir
> \setuparranging[direction=r2l] % will flush pages backward
>
> so l2r and r2l values; as they are part of the align mechanism then,  
> they are automatically part of all commands that have a align key

This sounds very good for me.

While we are in it, I'd suggest that the current implicit bidi to be
revised, currently it is broken. I suggest to be implement Unicode BiDi
algorithm[1], and the "higher-level protocols[2]" part is worthy
investigating. Also, I think it should be decoupled from character
mirroring, so that one can enable mirroring while explicitly setting
text direction. Also, some characters that had assigned mirrored
property in Unicode 5.0.0 has been reversed in later revisions[3]
because it "affects deployed data" (the source of all evil!), this
includes quotation marks, so we need to handle mirroring of those
characters as part of the suggested higher-level protocols as well.


[1]http://www.unicode.org/reports/tr9/
[2]http://www.unicode.org/reports/tr9/#Higher-Level_Protocols
[3]http://unicode.org/versions/corrigendum6.html

Regards,
 Khaled


-- 
 Khaled Hosny
 Arabic localiser and member of Arabeyes.org team
 Free font developer