[XeTeX] Let's discuss \mathchar again

[Will Robertson]

On 13/12/2005, at 20:33 , Jonathan Kew wrote:

> If I may nit-pick, what \mathchar could (potentially) give you  
> access to would be Unicode *characters*. There are no such things  
> as "Unicode glyphs".

Please correct me as much as you can! My terminology  (clearly) isn't  
rigourous at the moment, and I would be very embarrassed to keep  
making such obvious mistakes!

[extensible chars & the problem between unicode slots and multiple  
glyphs]
> Sounds like a perfect fit for an OpenType or AAT feature.... but  
> such a feature will need to be designed in association with both  
> the font developers and the application writers who will use it. I  
> don't think it's quite as simple as widening \mathchar and banging  
> out some new tables like those in plain.tex; that would get you a  
> long way, but not quite *all* the way.

Right, we can immediately rule out the extensibles, but at a pinch  
they might even be able to come from the old Computer Modern for the  
time being. Mathchar that works over (>16k) unicode ranges would get  
us far enough that I think it's worth considering.

At the same time, to keep compatibility with the old input methods,  
we'll need a separate family for every shape of roman letter that we  
want to input as an ascii glyph, so 16 of them might not be enough,  
but 256 surely will.

Sorry to pester!

Will