//  RepeatString.,ava
//  Demonstrates the use of an iterator to generate a potentially 
//  infinite sequence.
//
//  If you define an object w of class RepeatString with argument s and then 
//  create an iterator for w, the iterator will first return s, then
//  s+s then S+s+s etc.

import java.util.Iterator; 

public class RepeatString implements Iterable<String> {
   public String w; // String to be repeated

   public RepeatString(String w) {  // Constructor
       this.w = w;  
     }
    
   public Iterator<String> iterator() {
       Iterator<String> ic = new Iterator<String>() {
           private String s = "";  // current state
  
           public boolean hasNext() { return true; }

           public String next() {
               s = s+w;
               return s;
              }
    
           public void remove() { }  // stub
      };
      return ic;
 }
     public static void main(String[] args) {
          RepeatString w = new RepeatString("a");
          Iterator<String> ic = w.iterator();
          for (int i=0; i < 10; i++)
            System.out.print(ic.next() + " ");
          System.out.println();
         }
}