Re: Lua registry, environment, and threads.

["Juris Kalnins" <juris@...>]

On Mon, 11 Jan 2010 17:08:06 +0200, Luiz Henrique de Figueiredo  
<lhf@tecgraf.puc-rio.br> wrote:

> > But I'm feeling 98% sure "in nil do ... end" never will become valid  
> > Lua.
>
> It is valid in 5.2 and it forces (at runtime) that the block does not
> contain any references to global variables.
>
>    Lua 5.2.0 (work1)  Copyright (C) 1994-2008 Lua.org, PUC-Rio
>    > in nil do a=1 end
>    stdin:1: attempt to index local '(environment)' (a nil value)

I was wrong, thanks for correcting.
It almost allows non-tables as the environment! Just tried:

local a = newproxy(true)
local print = print
getmetatable(a).__index = function (v, x) print(x) return "ret" end
in a do
  print(key1);
  (function () print(key2) end) ();
end

Which outputs:

key1
ret
./src/lua: testen.lua:6: environment is not a table: cannot create closure

Kind of sad :(
Userdata works as environment in the 'in .. do .. end', which is great new  
feature,
but still doesn't work in closures...