//: Snake.java
//////////////////////////////////////////////////
// Copyright (c) Bruce Eckel, 1998
// Source code file from the book "Thinking in Java"
// All rights reserved EXCEPT as allowed by the
// following statements: You can freely use this file
// for your own work (personal or commercial),
// including modifications and distribution in
// executable form only. Permission is granted to use
// this file in classroom situations, including its
// use in presentation materials, as long as the book
// "Thinking in Java" is cited as the source. 
// Except in classroom situations, you cannot copy
// and distribute this code; instead, the sole
// distribution point is http://www.BruceEckel.com 
// (and official mirror sites) where it is
// freely available. You cannot remove this
// copyright and notice. You cannot distribute
// modified versions of the source code in this
// package. You cannot use this file in printed
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// author. Bruce Eckel makes no representation about
// the suitability of this software for any purpose.
// It is provided "as is" without express or implied
// warranty of any kind, including any implied
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// particular purpose or non-infringement. The entire
// risk as to the quality and performance of the
// software is with you. Bruce Eckel and the
// publisher shall not be liable for any damages
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/////////////////////////////////////////////////

// Tests cloning to see if destination of
// handles are also cloned.

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