[NTG-context] protected macro vs protected luacall

[Hans Hagen]

On 1/26/2023 9:33 PM, Henri Menke via ntg-context wrote:
> \directlua{
>    userdata = userdata or {}
>    function userdata.test()
>      tex.print("\string\\numexpr 17\string\\relax")
>    end
> }
> 
> \tt
> \protected\def\test{\directlua{userdata.test()}}
> \meaning\test\par
> \edef\x{\test}\meaning\x\par
> \the\test
> 
> \directlua{
>    local t = lua.get_functions_table()
>    t[\string#t + 1] = userdata.test
>    token.set_lua("test", userdata.test, \string#t, "protected")
> }
> \meaning\test\par
> \edef\x{\test}\meaning\x\par
> \the\test
from the code it looks like we're talking plain luatex ...

\the is very selective and doesn't work for all primitives or macros

compare it to \number which accepts any number representation following 
it while \the doesn't work ok 123

that said, your set_lua is wrong and passes a function as well as an index

\directlua{
    lua.get_functions_table()[999] = function()
      tex.print("\string\\numexpr 17\string\\relax")
    end
    token.set_lua("test", 999)
}

\the    \test % needs the \numexpr

\number \test % doesn't

\count0 \test % needs the \numexpr

\count0=\test % doesn't

etc

Hans


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