//: Sequence.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
// media without the express permission of the
// 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
// warranty of merchantability, fitness for a
// 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
// suffered by you or any third party as a result of
// using or distributing software. In no event will
// Bruce Eckel or the publisher be liable for any
// lost revenue, profit, or data, or for direct,
// indirect, special, consequential, incidental, or
// punitive damages, however caused and regardless of
// the theory of liability, arising out of the use of
// or inability to use software, even if Bruce Eckel
// and the publisher have been advised of the
// possibility of such damages. Should the software
// prove defective, you assume the cost of all
// necessary servicing, repair, or correction. If you
// think you've found an error, please email all
// modified files with clearly commented changes to:
// Bruce@EckelObjects.com. (Please use the same
// address for non-code errors found in the book.)
/////////////////////////////////////////////////
// Holds a sequence of Objects
interface Selector {
boolean end();
Object current();
void next();
}
public class Sequence {
private Object[] o;
private int next = 0;
public Sequence(int size) {
o = new Object[size];
}
public void add(Object x) {
if(next < o.length) {
o[next] = x;
next++;
}
}
private class SSelector implements Selector {
int i = 0;
public boolean end() {
return i == o.length;
}
public Object current() {
return o[i];
}
public void next() {
if(i < o.length) i++;
}
}
public Selector getSelector() {
return new SSelector();
}
public static void main(String[] args) {
Sequence s = new Sequence(10);
for(int i = 0; i < 10; i++)
s.add(Integer.toString(i));
Selector sl = s.getSelector();
while(!sl.end()) {
System.out.println((String)sl.current());
sl.next();
}
}
} ///:~ |