Re: a new proposal for environments

[Tomas Guisasola Gorham <tomas@...>]

	Hi Enrico

> I don't like the idea of reusing the _G name; it could lead to confusion 
> because _G and _ENV are quite different beasts. Consider (5.1):
>
> a = 3
> print(a) --> 3
> print(_G.a) --> 3
>
> _G = { a = 4 }
> print(a) --> 3  [*]
> print(_G.a) --> 4
>
> [*] with _ENV instead of _G, this would be 4 (if I'm not mistaken).
	In fact, it will throw an error, because print (or _ENV.print)
does not exist :-)

> In short, _G is just a reference to the globals table; changing _G will not 
> change the global table.
> On the other hand, _ENV is an upvalue containing the current 'globals' table; 
> changing _ENV will change the 'globals'.
	Not exactly:

_G.print = nil -- equivalent to _ENV.print = nil

	Regards,
		Tomás