/** * Obtain the contents of the current node. * * @timing O(1) * @precond itemExists() */ public I item() throws NoCurrentItem280Exception { if (!itemExists()) throw new NoCurrentItem280Exception("A current item must exist"); return cur.item(); }
/** * Advance to the root of the ith subtree. * * @timing O(1) * @param i subtree to advance to */ public void goSubtree(int i) { parent = cur; index = i; cur = cur.subnode(i); }