On Mon, Dec 20, 2010 at 07:45:21AM -0800, Michiel Kamermans wrote: > > >I long had that on my todo list, but I'm yet to figure out a proper user > >interface for it; one needs to take care of different font styles, > >optical sizes etc. e.g. English ARABIC {\it english ARABIC} should work > >and get the Arabic text assigned the proper italic font and so on. > > > >The code at lua end is quit trivial, once the script->font mapping is > >defined which is actually the tricky part. > > Hmm... that sounds much more narrow than what you can do with > XeTeX's intercharclass behaviour, and much more like just > font-switching.
I'm not sure what XeTeX's intercharclass can do (I never understood it to be honest, it just looked too limited to me). > I would imagine that something like what XeTeX > offers makes it much easier to say "if arabic character from non > arabic, RTL and font switch (and whatever else is requested by the > user)". Actually Jonathan said before intercharclass can't be used to do bidirectional switching, while in luatex you have direct access to node list and I actually have an implementation of Unicode bidi algorithm written entirely in lua[1] (I usually use it with ConTeXt, so the LaTeX part is not very well tested at the moment). > But perhaps LuaTeX wants to do these two things separately, > which would of course be equally fine, just requiring a different > approach in terms of packageness Font switching and text directionality are two separate issues and even and can't be done in one step; bidi is very tricky and not just Arabic==RTL and English==LTR, even font switching can be a bit tricky when you consider characters that don't belong to specific script (like most punctuation marks). [1] http://github.com/khaledhosny/luadirections Regards, Khaled -- Khaled Hosny Arabic localiser and member of Arabeyes.org team Free font developer -------------------------------------------------- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex