// references/Snake.java
// (c)2017 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
// Tests cloning to see if reference
// destinations are also cloned

public class Snake implements Cloneable {
 private Snake next;
 private char c;
 // Value of i == number of segments
 public Snake(int i, char x) {
 c = x;
 if(--i > 0)
 next = new Snake(i, (char)(x + 1));
 }
 public void increment() {
 c++;
 if(next != null)
 next.increment();
 }
 @Override
 public String toString() {
 String s = ":" + c;
 if(next != null)
 s += next.toString();
 return s;
 }
 @Override
 public Snake clone() {
 try {
 return (Snake)super.clone();
 } catch(CloneNotSupportedException e) {
 throw new RuntimeException(e);
 }
 }
 public static void main(String[] args) {
 Snake s = new Snake(5, 'a');
 System.out.println("s = " + s);
 Snake s2 = s.clone();
 System.out.println("s2 = " + s2);
 s.increment();
 System.out.println(
 "after s.increment, s2 = " + s2);
 }
}
/* Output:
s = :a:b:c:d:e
s2 = :a:b:c:d:e
after s.increment, s2 = :a:c:d:e:f
*/