Re: How two C-closures can share an upvalue??

["D Burgess" <dburgess@...>]

Case 1

static int val;
lua_pushlightuserdata(L, &val);
lua_pushcclosurer(L,  myfunc2, 1);
lua_pushlightuserdata(L, &val);
lua_pushcclosurer(L,  myfunc2, 1);

Case 2
If its lua values you wish to share (rather than C) create the value
as a table entry and use the table for the upvalue.

David B

On 8/14/06, slonik.az@gmail.com <slonik.az@gmail.com> wrote:
> Hi Lua Experts,
> Lua closures can share their private state with each other by sharing
> their "outer local" variables. In the following code snippet "local
> cnt" is accessible by both cnt_step() and cnt_get() and no other
> function in the world could touch it.
>
> function cnt_init()
>    local cnt= 0
>    function cnt_step() cnt= cnt + 1 end
>    function cnt_get()  return cnt; end
> end
> cnt_init();
>
> I would like to achieve the same effect using C-closures. But I cannot
> figure out how?
> Roberto's book "Programming in Lua, 2-nd edition" that I recently
> bought shows how a C-closure stores its individual state in an upvalue
> (lua_pushcclosure). But here I need two functions to have an access to
> the same upvalue.
> Any help is greatly appreciated.
>
> Thanks and Best Regards,
> --Leo--