Re: Lua language extension for complex number and vector values

[Luiz Henrique de Figueiredo <lhf@...>]

> But do I understand it correctly that all complex values inside that
> function would be created as temporary values?

Yes.

> If so, what are the requirements for writing such "pure" functions?
> Is the following sufficient?
>  - does not write to global variables
>  - does not call non-pure functions
>  - does not create non-temporary objects with references to temporary  
> objects
>  - does not yield

Yes. You can even use local variables to hold intermediate results, as
long as you do not store them elsewhere.
 
> This is the part I don't understand. Garbage collection of the temporary  
> array
> will happen at some distant future time. How can "complex" ensure that
> temporary values will not be reused before that, or that when the table is
> collected it will not damage those values? Or is that not important?

The table will be alive at least until the function returns, so I don't see
a problem there. Also, it's an anonymous function and so is not stored
anywhere unless the function does, which it's not supposed to.
 
> That's why I want to understand the details.

I haven't implemented any of this. Of course, it's the details that matter
in the end...