Dirk, if you read through this topic, you'll see that I am well aware of the global metatable trick, which I am using.
However, if you have a project that has config files that are supposed to be "Lua", you either can hardly make additonal rules without getting people wondering or upset, or asking them to make magic like this, which gets you "I don't understand all this" messages.
This is IMHO another core issue the Lua team can only beat so far. That is, "you can make it all you want". At one point you want to have it at some small level to be a Lingua Franca, that is if you know Lua from WoW, you expect it to work the same way in LuaTex.
Especially if people are going to use third party libraries, the "change the language yourself as much as you want" idiom is slowly halting.
For me its for example the trailing comma in function calls we discussed a few weeks back. Its easy for me to change the lua parser, to allow it (it was a one line patch!). However, if I want to use it LuaTex, which is where the issue comes from since tex.print() can have many arguments spawned over several lines, where I often run into issues because of the last argument must not have a comma. Then I'd need to recompile LuaTex. Then I'd need to tell everybody in my team, they'd have to use costum adapted LuaTex package, using different Linux distributions, some are using Windows, so I'd need to change MikTex too...
I could also try and talk to the LuaTex people, which I honestly didn't even try, since I know already its going to be, "we are not a language design project, we're using PUC-Rio Lua as is (except the coroutines stuff they disabled).
