Re: a new proposal for environments

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

On Mon, 01 Mar 2010 14:31:21 +0200, Duncan Cross <duncan.cross@gmail.com>  
wrote:

> I'm not against the idea, but I'm a bit confused why it'd be better
> than just using an array as the 1 value?

answering to the "why better" part:
- it creates less data
- it is faster
- it considerably simplifies C side usage
- it reduces the size of the userdata when no Lua values are needed

> You do have to go through
> the extra step of retrieving the array before getting at the values,
> but you could always write helper functions/macros to help with that
> if it really bothers you.

Such helpers/macros would retrieve array, retrieve element of array, remove
array from the Lua stack. This would happen for every value you try to  
access.

As stated in the manual:
 " Environments associated with userdata have no meaning for Lua.
 " It is only a convenience feature for programmers
 " to associate a table to a userdata.
This is not a necessary feature. It is to simplify the C code.
You can as well use weak tables keyed by the userdata. So I think the more  
it
simplifies C side, the better.