In the first, we needs to define a minimum Lua version. Maybe 5.1+?
Because:
which are undefined unless the user defines them:
`floor` is valid and defined, see Lua 4.x.x documentation.
for example, still highlight math.sin but not sin because sin is not defined by default.
it's not true too: see Lua 4.x.x documentation.
Why did I think and write about Lua 4.x.x? It's simple: I see `strlen`, `strlower`, `strrep`, `strsub` and other.
P.S. `type` is a bad example: this is a function from the basic library.