Consider the following tex file:
\directlua{require "foo"}
\show\foo
\bye
where foo.lua is the single line
token.set_macro("foo","\\,")
When I run this, the result is as follows:
> \foo=macro:
->BAD,.
I understand how and why similar behaviour happens if \, is replaced by some
command name that is NOT known from before, such as \foo. But \, IS known, so I
had expected this to work. The same happens with any non-letter command name
that I have tried. (I originally ran into this in lualatex, where I wanted to
build a command expanding to a bunch of strings separated by \\, encoded as
\\\\ in the lua strings of course.)
Is it a bug, or have I misunderstood how this works?
(This is with TL 2019 on a mac. Luatex 1.10.0.)
– Harald
