Function postorder

publication/code/chapter08/avl.rs:432–441

(avl: &AvlTree<T>)

}

fn postorder<T: Clone + Ord + Debug>(avl: &AvlTree<T>) {
    match avl {
        Null => (),
        Tree(node) => {
            postorder(&node.left);
            postorder(&node.right);
            println!("key: {:?}", node.key);
        },
    }
}

fn levelorder<T: Clone + Ord + Debug>(avl: &AvlTree<T>) {
    let size = avl.size();