Module std.strict
Checks uses of undeclared global variables.
 All global variables must be 'declared' through a regular
 assignment (even assigning nil will do) in a top-level
 chunk before being used anywhere or assigned to inside a function.
To use this module, just require it near the start of your program.
 From Lua distribution (etc/strict.lua).
Functions
| __index (t, n) | Detect dereference of undeclared global. | 
| __newindex (t, n, v) | Detect assignment to undeclared global. |