data/train/RuthDirnfeld/1DV507/rd222dv_assign4/Queue.java

package rd222dv_assign4;

import java.util.Iterator;

public interface Queue <T> { //same interface as in assign2, only Object was replaced with T

	public int size(); // current queue size

	public boolean isEmpty(); // true if queue is empty

	public void enqueue(T element); // add element at end of queue

	public T dequeue(); // return and remove first element.

	public T first(); // return (without removing) first element

	public T last(); // return (without removing) last element

	public String toString(); // return a string representation of the queue content

	public Iterator <T> iterator(); // element iterator

}