Re: Lexical environments

[Duncan Cross <duncan.cross@...>]

On Tue, Dec 7, 2010 at 12:51 PM, Dirk Laurie <dpl@sun.ac.za> wrote:
> The Unofficial FAQ says:
>
> --[[
> 8.2 What are the new Lua 5.2 features?
> 8.2.1 Lexical Environments
>
> These define a block in which all global accesses happen in a given environment (which can be a table or userdata):
>
> t = {}
> in t do
>    x = 10
>    y = 20
> end
> => t == {x=10,y=10}
> --]]
>
> but the recently released alpha version of 5.2 does not allow the construct,
> neither the BNF specification nor the 'lua' executable.
>
> Considered but not accepted?  Planned but not yet implemented?
>
> Dirk
>
>

Dropped. It was present in the earliest work version, but it was
decided later that specially treating the _ENV variable was the way to
go instead. See Roberto's post here:

http://lua-users.org/lists/lua-l/2010-02/msg00753.html


-Duncan