Re: The removal of function environments: An opportunity for optimization?

[Roberto Ierusalimschy <roberto@...>]

> >_ENV is a regular variable (and so a regular upvalue that may be
> >shared). Then it does.
> 	I thought it was a "regular local variable", since you defined:
> 
> Any chunk is compiled as if surronded by the following code:
> local _ENV = <some value>; function (...) <chunk> end
> 
> 	Thus, I thought the above code (correcting `f2' to `function')
> could be rewritten as:
> 
> local _ENV = _ENV -- In Lua 5.1 it could be written `local _ENV = _G'
> function f1()
>   local _ENV = _ENV
>   return function()
>     _ENV = {}
>   end
> end
> 
> 	In this case, I think the inner statement would not change f1's _ENV.
> What am I missing?

What gets the surrounding _ENV declaration are *chunks*, not functions.
Everything inside the same chunk (a compilation unit) share the same
_ENV, unless there are explicit declarations of other _ENVs.

-- Roberto