On 3/20/2021 4:00 PM, Christoph Reller wrote:
> On Sat, Mar 20, 2021 at 12:12 PM Hans Hagen <j.hagen@xs4all.nl
> <mailto:j.hagen@xs4all.nl>> wrote:
>
>     On 3/20/2021 8:24 AM, Aditya Mahajan wrote:
>      > On Sat, 20 Mar 2021, Christoph Reller wrote:
>      >> Of course we can do this in lua:
>      >>
>      >> if tex.modes["A"] and not tex.modes{"B"] then
>      >> ...
>      >> end
>      >
>      > ... which means that you can use that at the context end as well
>     (old feature).
>      > Save the following as test.mkix (or add "% macros=mkix" as the
>     first line):
>      >
>      > ```
>      > \starttext
>      > <?lua if tex.modes["A"] and not tex.modes["B"] then ?>
>      > \starttyping
>      > A and not B
>      > \stoptyping
>      > <?lua else ?>
>      > \starttyping
>      > not (A and not B)
>      > \stoptyping
>      > <?lua end ?>
>      > \stoptext
>     a neat application!
>
>
> Thank you for this hint, Aditya. This would be a very nice solution
> indeed. But it does not seem to work:
>
> % macros=mkix
> \definemode[A][yes]
> \starttext
> \startluacode
>    if tex.modes['A'] then
>      context("A")
>    end
> \stopluacode
> <?lua if tex.modes['A'] then ?>
> A
> <?lua end ?>
> \stoptext
>
> With ConTeXt LMTX 2021.03.17 the output of the above is a single "A". I
> would expect two. What am I doing wrong?

When the file gets preprocessed the mode is not known

context --mode=A foo.tex

it does of course also work when you set the mode in a parent file and
then include foo.tex