RE: References to tables

[Nick Trout <Nick.Trout@...>]

> This seems like a question to which the answer should be 
> obvious, but I'm
> going to double-check and ask it anyway. I'm wondering if 
> it's possible to
> get a reference to a table which is passed to a C function, 
> if that table is
> created during the function call with a table constructor, instead of
> created ahead of time. Here's an example of what I want to do:

Yes its possible to do what you say. Look at the Lua source code for
examples.

eg.
math_min for variable args.
luaB_tinsert table manipulation.

For parsing your table argument see previous post for lua2c.

Regards,
Nick


> C code snippet:
> 
> int somecfunction(lua_State *L)
> {
>     char *a_string;
>     int table_reference;
> 
>     a_string = lua_tostring(L, 1);
>     table_reference = lua_getref(L, 1);
> }
> 
> Lua code snippet:
> 
> x = {1st_number, 2nd_number, 3rd_number}
> somecfunction(a_string, x); -- I'm pretty sure this will work
> somecfunction(a_string, {1st_number, 2nd_number, 
> 3rd_number}); -- but I'm
> not sure about this one.
> 
> Will both of the above function calls work as expected? Also, 
> since I'm
> asking, is the correct way to force Lua to perform a 
> garbage-collection to
> call lua_setgcthreshold() with an argument of zero?
>