public void cons(X elem) {
assertUnpublished();
if (head.isEmpty()) {
this.end = new BoundedList<>(elem);
this.head = this.end;
} else {
this.head = new BoundedList<>(elem, this.head);
}
}
public int size() {
int size = 0;
Seq<X> seq = this;
while (seq.nonEmpty()) {
assert seq.isEmpty() || seq instanceof BoundedList;
seq = seq.tail();
size++;
}
return size;
}
public void add(X elem) {
assertUnpublished();
List<X> newEnd = new BoundedList<>(elem);
if (head.isEmpty()) {
this.head = newEnd;
this.end = newEnd;
} else {
this.end.tail = newEnd;
this.end = newEnd;
}
}
/**
* A covariant constructor for adding an element at the front of a Seq.
*
* @param elem an element reference. Can be null.
* @param tail any type of Seq. Cannot be null.
* @param <Y> type of the element added at the front of the given Seq.
* @return a new Seq made of the given arguments using the List class.
*/
public static <Y> Seq<Y> cons(Y elem, Seq<? extends Y> tail) {
if (tail.isEmpty() || tail instanceof BoundedList) return new BoundedList<>(elem, tail);
else return new List<>(elem, tail);
}