[luatex] a question about the names \Umathcharnumdef etc

[Joseph Wright]

On 15/10/2015 17:36, jfbu wrote:
> Hi,
> 
> as people reported problems with mathastext under lualatex I have become aware
> that \luatexUmathcharnumdef etc... have been removed and \Umathcharnumdef etc...
> must be used  instead.
> 
> as I didn't find the info immediately I am asking here: how should I test
> (version number, date etc...)
> when one should use \luatexUmathcharnumdef and
> when on should use \Umathcharnumdef ?
> 
> or perhaps \Umathcharnumdef was always ok ?
> 
> I would like to not break people's old installation thus I would be
> glad to use \Umathcharnumdef  if I am told it works with all earlier lualatex
> 
> best wishes
> 
> Jean-François

Hello Jean-François,

The 'real' names of the primitives have always been just \Umath... For
some time they've been enabled with the "luatex" prefix.. The LaTeX team
have recently taken a more 'active' interest in directly supporting
LuaTeX (and XeTeX) by modifying latex.ltx to 'know' about these engines.
As part of that process, we've revised the approach to the newer
primitives and dropped the prefix 'out of the box'.

For code that needs to work both with older (pre 2015/10/01) and newer
(2015/10/01 onward) kernel releases, adding

    \directlua{
      tex.enableprimitives("luatex", tex.extraprimitives("Umath"))
    }

(for just the Umath set) will do the job. Alternatively, if the code in
your package gets modified to drop the prefix then

    \directlua{
      tex.enableprimitives("", tex.extraprimitives("Umath"))
    }

will ensure that the 'natural' names are available with older kernel
releases.

Regards,

Joseph