Sequence.java

package chapter10;

public class Sequence {

	private Object[] items;
	private int next=0;
	public Sequence(int size) {
		items=new Object[size];
	}
	public void add(Object x){
		if(next<items.length){
			items[next++]=x;
		}
	}
	private class SequenceSelector implements Selector{

		private int i=0;
		public boolean end() {
			return i==items.length;
		}

		public Object current() {
			return items[i];
		}

		public void next() {
			if(i<items.length)
				i++;
		}
	}
	public Selector selector(){
		return new SequenceSelector();
	}
	public static void main(String[] args) {
		Sequence sequence=new Sequence(10);
		for (int i = 0; i < 10; i++) {
			sequence.add(Integer.toString(i));
		}
		Selector selector=sequence.selector();
		while(!selector.end()){
			System.out.println(selector.current()+" ");
			selector.next();
		}
	}
}