Re: table deep copy in C/CPP

[Asko Kauppi <askok@...>]

Mark Hamburg kirjoitti 20.3.2010 kello 19:27:

> On Mar 20, 2010, at 1:54 AM, Asko Kauppi wrote:
>
> > If you are interested in copying functions, the Lanes code can do  
> > that. It also copies upvalues.
> >
> > -asko
>
> Does it also copy the environment? How does it decide where to stop?  
> For example, if I stick math.sin into a local variable math_sin and  
> reference this as an upvalue in the function I'm passing, what does  
> it do?

I think it did not copy the environment, though that could actually be  
implemented if needed.

It would copy the function given as upvalue. It only stops when  
there's a recursion (i.e. it cannot copy a function which has itself  
as upvalue, though even this could possibly be implemented, if needed).

One reason I made it was to see just how far one can go with existing  
Lua API. Quite far, actually.

The responsibility of not overusing it (since any copying would  
naturally have a runtime penalty) is up to the application programmer.

Naturally, once the copying has been done the two upvalues in the two  
separate Lua states are completely detached. There is a separate  
concept of shared states for inter-state communications.

- Asko



> Mark