Module:No globals

Documentation for this module may be created at Module:No globals/doc

 1 local mt = getmetatable(_G) or {}
 2 function mt.__index (t, k)
 3 	if k ~= 'arg' then
 4 		error('Tried to read nil global ' .. tostring(k), 2)
 5 	end
 6 	return nil
 7 end
 8 function mt.__newindex(t, k, v)
 9 	if k ~= 'arg' then
10 		error('Tried to write global ' .. tostring(k), 2)
11 	end
12 	rawset(t, k, v)
13 end
14 setmetatable(_G, mt)