Module:No globals

    From Commons

    Documentation for this module may be created at 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)