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: ->\bar \blub BAD!. l.254 \show\foo

so the \blub works, but not the \!. How can one repair this? -- Ulrike Fischer https://www.troubleshooting-tex.de/