Re: [possible patch] Basic fontspec code for LuaLaTeX and XelaTeX (was "LaTeX export: when is it more useful...")

[Max Nikulin]

On 11/07/2022 21:23, Juan Manuel Macías wrote:
> Max Nikulin writes:
> > >  \\ifpdftex
> > >    \\relax
> > >    \\else
> >
> > Is it the case of latex as the old engine with tex->dvi->ps workflow
> > besides new XeTeX and LuaTeX? However such engine is not used by Org.
>
> According to the iftex documentation (p. 2):
>
> \ifpdftex, \ifPDFTeX
> True if PDFTEX is in use (whether writing PDF or DVI), so this is true
> for documents processed with both the latex and pdflatex commands.
>
> So the code says: if pdfTeX is used, do nothing; else, add this (luatex
> and xetex related) code.

I have noticed the \iftutex command in the iftex.sty manual. It detects 
XeTeX, LuaTeX, LuaHBTeX, so it should be more suitable here.

At first I had intention to suggest \ifdefined\XeTeXrevision 
\ifdefined\XeTeXrevision you mentioned in
Re [PATCH] ox-latex.el: Unify in one single list Babel and Polyglossia 
languages alists. Fri, 15 Jul 2022 14:36:07 +0000. 
878rou30ko.fsf@posteo.net">https://list.orgmode.org/878rou30ko.fsf@posteo.net

P.S. I do not remember if CMU Serif, etc. family (that is Computer 
Modern Unicode) has been mentioned in this thread. It is not installed 
but default, but allows to generate documents with traditional TeX fonts.