agl_node *agl_node_create (struct userdata *, agl_node *);
void agl_node_destroy (struct userdata *, agl_node *);
+agl_node_type agl_node_type_from_str (const char *);
const char *agl_node_type_str (agl_node_type);
const char *agl_node_direction_str (agl_direction);