[luatex] Missing math primitive & assorted remarks

[Will Robertson]

On 13/07/2010, at 4:32 PM, Taco Hoekwater wrote:

>> I know this is a little late to be reporting the problem... I just
>> realised that I missed documenting a maths primitive in xetexref, and
>> LuaTeX is also missing it.
> 
> That happened precisely because the XeTeX documentation was missing.

Yep, sorry about that; my fault.

> What does XeTeX do with \the\mathcode`\( when
> 
>  \Umathcode `\( = "4 "20 "1D400
> 
> or something?

\Umathcode `\( = "4 "4 "28
\showthe\mathcode`\(

-> 17448

\Umathcode `\( = "4 "20 "1D400
\showthe\mathcode`\(

-> ! Extended mathchar used as mathchar (545379328).


I don't know if this is necessarily behaviour that you'd like to replicate (you could also imagine using the legacy output for regular old mathchars and using the extended output for larger values). Like I said, I'm not aware of any direct problems this might cause; I simply wanted to let you know just in case.

Thanks,
-- Will