Re: Packaging and importing

[Tomas <tomas@...>]

	Hi Chris,

On Sun, 14 Aug 2005, Chris Marrin wrote:

> Tomas wrote:
>
> > ...
> > > > Also, has anyone made a proposal for how you can promote all the members 
> > > > of "a" into the namespace of the module that requires "a"?
> >
> >     Why don't you inherit the symbols from "a" with something
> > like:
> >
> > require"a"
> > _M = {}
> > setmetatable (_M, { __index = a }) -- inherit from "a"
> > setfenv (1, _M) -- new environment (global table)
> >
> >     If "a" inherits from the global table you'll get all global
> > through it!
>
> Ok, I'm liking this. Now I think my only question is whether all functions 
> defined after the setfenv() inherit the same environment. If so, then I think 
> I can make nice isolated objects this way.
>
> Of course, I think I might have to do something a bit more complex with 
> __index, if I want this module to be able to access the real global table as 
> well, right?
	I was assuming that module "a" inherits from the global env
so you'll have a chain: _M inherits from a which inherits from _G.

> I would have to make __index a function which first checked in 
> 'a' then in _G. Or maybe I just want to go through and copy each member of 
> 'a' (or some subset) into _M. then I could do:
>
>    setmetatable (_M, { __index = _G })
>    ... add some or all of the members of 'a' to _M ...
>
> then I would be able to see everything I need, wouldn't I???
	I do think so (if I'm understanding what you mean).
	Another approach will be to add "a" as a local:

local a = a

	Then you'll have access to the table "a" instead of access to
'a table called "a"'.

		Tomas