[cap-talk] Lua, Javascript, and the Object Capability Model

[James Graves]

Matej Kosik wrote:
> Let me rephrase the question (concerning connectivity by introduction)
> more clearly.
>
> Suppose that there are two mutually suspicious subsystems (A and B).
>
> A has the authority to draw on the entire screen.
>
> A wants to let B render itself to a rectangular window. Can A give B
> some capability that can be then used by B to render itself into that
> rectangular area?
>
> (suppose that neither A nor B can manipulate each other's global tables
> defining meanings of names of procedures)
>   

Well, if A and B are in the same Lua thread then it is certainly 
possible to pass a reference to a function from A to B.  Either as an 
argument in a function call, or as a return value, or stored in a data 
structure that A and B share.

If you want to go between threads, that's going to be analogous to 
talking cross-vat.

James