Re: Backport of Lua 5.2 "in" scoping

[David Kastrup <dak@...>]

Matthew Wild <mwild1@gmail.com> writes:

> I'm interested whether the patch is correct. From the other thread I
> thought I understood that functions would stop using the environment
> they were defined in by default, and instead the environment they are
> called in. Such that this simple example would fail (due to lack of
> print in env):
>
>    function sayhello() print("Hello") end
>    env = { sayhello = sayhello }
>    in env do sayhello() end
>
> Am I wrong in my understanding?

I think so.  Since no local "print" exists at the time of compilation,
this is resolved at compile time to the equivalent of

_G.print("Hello")

Now if you change _G.print, this will affect sayhello's operation I
should think.  But "in" does not touch _G AFAICT, merely sets it aside
for the purpose of resolving symbols.  Already resolved symbols will
retain their resolution (though not necessarily their value).

That's my understanding.

-- 
David Kastrup