# [Dev-luatex] commands with a non-letter in token.set_macro

Ulrike Fischer news3 at nililand.de
Tue Dec 10 22:21:11 CET 2019

Commands that should be use in token.set_macro must already exist.
But while it is easy to predefine a command like \blub it seems not
to be possible to do it with commands consisting of a \ with a
non-letter.

E.g. I put this in a luatest.lua

token.set_macro("foo","\\bar\\blub\\!")

and then compile

\def\!{hallo}
\def\blub{hallo}
\directlua{require"luatest"}
\show\foo
\bye

I get:

> \foo=macro:
l.254 \show\foo

so the \blub works, but not the \!.

How can one repair this?

--
Ulrike Fischer
https://www.troubleshooting-tex.de/