@Override
default <U> Tree<Tuple2<T, U>> zipAll(Iterable<U> that, T thisElem, U thatElem) {
Objects.requireNonNull(that, "that is null");
if (isEmpty()) {
return Iterator.ofAll(that).map(elem -> Tuple.of(thisElem, elem)).toTree();
} else {
final java.util.Iterator<U> thatIter = that.iterator();
final Tree<Tuple2<T, U>> tree = ZipAll.apply((Node<T>) this, thatIter, thatElem);
if (thatIter.hasNext()) {
final Iterable<Node<Tuple2<T, U>>> remainder =
Iterator.ofAll(thatIter).map(elem -> Tree.of(Tuple.of(thisElem, elem)));
return new Node<>(tree.getValue(), tree.getChildren().appendAll(remainder));
} else {
return tree;
}
}
}
@SuppressWarnings("unchecked")
static <T, U> Tree<Tuple2<T, U>> apply(Node<T> node, java.util.Iterator<U> that, U thatElem) {
if (!that.hasNext()) {
return node.map(value -> Tuple.of(value, thatElem));
} else {
final Tuple2<T, U> value = Tuple.of(node.getValue(), that.next());
final List<Node<Tuple2<T, U>>> children =
(List<Node<Tuple2<T, U>>>)
(Object)
node.getChildren()
.map(child -> ZipAll.apply(child, that, thatElem))
.filter(Tree::isDefined);
return new Node<>(value, children);
}
}