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Thanks for a quick reply =)

I noticed I wasn't pushing the nil,

my code now looks exactly like yours, but it's still error-ing;

correct me if I'm wrong but,


when you go to recurse, you pass in an index of -1 for lua_next to
use, which is the top of the stack, yet in the function you then push
a nil, which is then at the top of the stack, thus using -1 to
reference the table would be wrong?

-Raymond

On 1/19/07, Jérôme VUARAND <jerome.vuarand@gmail.com> wrote:

2007/1/19, Raymond Jacobs <raymondj@gmail.com>:
> int idx=LUA_GLOBALSINDEX;
> lua_getfenv(l,idx);
>
> while(lua_next(l,idx)!=0)
> {
>                 const char* key=lua_tostring(l,-2);
>
>                 //get value at -1 index and check type of it
>
>                 //do somthing with key and value based on type of value
>                 //if value is a table call this function again to traverse it, then
> continue here
>
>
>                 lua_pop(l,1);
> }
>
> it seems in theory it should be as simple as doing another lua_next,
> however I've not been able to get it to work, and I end up crashing,
> likely due to corupting the stack; either my logic or how I'm going
> about it is wrong, an example of how to do this in the C API would be
> really helpful.

You forget to push an initial nil on the stack before entering you
while loop (see lua_next documentation example). Here is what your
code could look like :

int dosomestuff(lua_State* L, int index)
{
    // Do something with value at index (which is not a table)
    return 1;
}

int parsetable(lua_State* L, int index)
{
    // Push an initial nil to init lua_next
    lua_pushnil(L);
    // Parse the table at index
    while (lua_next(index)!=0)
    {
        if (lua_istable(L, -1)
        {
            parsetable(L, -1);
        }
        else
        {
            dosomestuff(L, -1);
        }
        // Pop value, keep key
        lua_pop(L, 1);
    }
    return 1;
}

int parseglobals(lua_State* L)
{
    parsetable(L, LUA_GLOBALSINDEX);
    return 0;
}