堆栈没学好撸啊很苦恼

/**
 * [B] -- alias, nil [T]
 *        |      |_________________lua_pushnil
 *        |________________________lua_next(_, -2)
 *
 *
 *                _________________lua_tostring(_, -2)
 *               |
 * [B] -- alias, key, value [T]
 *               |    |____________lua_isstring(_, -1)
 *               |                 lua_tostring(_, -1)
 *               |                 lua_isfunction(_, -1)
 *               |
 *               |_________________lua_pop(_, 1)
 *                                 luaL_ref
 *
 * [B] -- alias, key [T]
 *        |________________________lua_next(_, -2)
 */
lua_pushnil(f_L);
while (lua_next(f_L, -2) != 0) {
    key = lua_tostring(f_L, -2);
    if (lua_isstring(f_L, -1)) {
        value = lua_tostring(f_L, -1);
        printf("key(%s) = value(%s)\n", key, value);
        lua_pop(f_L, 1);
    } else if (lua_isfunction(f_L, -1)) {
        printf("got you type(%d)\n", lua_type(f_L, -1));
        // lua_call(f_L, 0, 0); // 调用后函数参数连同函数名已经被lua虚拟机自动弹出
        g_agent = luaL_ref(f_L, LUA_REGISTRYINDEX); // luaL_ref也会自动弹出
    }
}