Re: turn a lua function into a lua closure?

[Graham Wakefield <lists@...>]

Ah, I should have said, a lua function, not a CFunction.

Just tried this and I get a EXC_BAD_ACCESS; which I guess is due to  
trying to convert a lua function into a lua_CFunction.

Nevermeind, and thanks anyway.

On Feb 26, 2007, at 7:53 PM, Mark Edgar wrote:

> On 2/26/07, Graham Wakefield <lists@grahamwakefield.net> wrote:
> > Hi,
> >
> > Is it possible to make a duplicate of a function in the C API?
>
> I believe the following should work:
>
> /* cfunction envtable -- newcfunction */
> int makedupenv(lua_State * L)
> {
>  lua_CFunction f = lua_tocfunction(L, 1);
>  luaL_argcheck(L, f != 0, 1, "expected C function");
>  luaL_checktable(L, 2, LUA_TTABLE);
>  /* note that the copy will not have any upvalues, even if the  
> original does */
>  lua_pushcfunction(L, f);
>  lua_pushvalue(L, 1);
>  lua_setfenv(L, 1);
>  return 1;
> }
>
> You can use lua_getupvalue() to duplicate the C function with all  
> its upvalues.
>
>     -Mark