[XeTeX] Numerals in Right-to-Left

[Otared Kavian]

Dear Jonathan Kew, Dear List members,

Sometimes ago I discovered XeTeX on Mac OS X (through a message 
posted by Adam Lindsay for ConTeXt users: thanks, Adam). You have 
done a wonderful work and letting the whole community using it, is 
really both a great achievement and a great decision! Thank you.

I have two basic questions (I searched the archives but did not find 
the answer: so if I am repeating a question already treated here, 
please forgive me).

1) I would like to use (Plain) XeTeX to write in Persian (indeed the 
same problem appears with Arabic). In Persian the digits 0--9 are 
different than the so-called "arabic numerals" (some call them indic 
or persian numerals, but I am not sure about the correct 
denomination). Now, in XeTeX when the file contains these numerals, 
in the typeset they don't appear. In a message of Jonathan K. 
answering a question about Korean there is a word about this but I 
don't know how to solve the problem.
Can anyone tell us more?

2) It seems that it is possible to use ConTeXt with XeTeX, that is to 
compile a format using XeTeX, and call it (for instance) XeConTeXt. 
Can anyone (maybe Adam Lindasy...) tell us more about this? (Even if 
not all the features of ConTeXt are present in XeConTeXt, still I 
think it is interesting to use it, given that ConTeXt is such a 
beautiful environment).

Best regards: Otared K.