3 -- checks uses of undeclared global variables
4 -- All global variables must be 'declared' through a regular assignment
5 -- (even assigning nil will do) in a main chunk before being used
6 -- anywhere or assigned to inside a function.
9 local mt = getmetatable(_G)
18 mt.__newindex = function (t, n, v)
19 if __STRICT and not mt.__declared[n] then
20 local w = debug.getinfo(2, "S").what
21 if w ~= "main" and w ~= "C" then
22 error("assign to undeclared variable '"..n.."'", 2)
24 mt.__declared[n] = true
29 mt.__index = function (t, n)
30 if not mt.__declared[n] and debug.getinfo(2, "S").what ~= "C" then
31 error("variable '"..n.."' is not declared", 2)
37 for _, v in ipairs{...} do mt.__declared[v] = true end