Module:No globals

Module documentation This module is copied from the English Wikipedia page en:Module:No globals. It has no documentation, and relevant information may be found at the corresponding English Wikipedia documentation page. For more details see the editing history of the module. The above documentation is transcluded from Module:No globals/doc.

---

local mt = getmetatable(_G) or {}
function mt.__index (t, k)
	if k ~= 'arg' then
		error('Tried to read nil global ' .. tostring(k), 2)
	end
	return nil
end
function mt.__newindex(t, k, v)
	if k ~= 'arg' then
		error('Tried to write global ' .. tostring(k), 2)
	end
	rawset(t, k, v)
end
setmetatable(_G, mt)