49 lines
1.2 KiB
Java
49 lines
1.2 KiB
Java
// innerclasses/Sequence.java
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// (c)2020 MindView LLC: see Copyright.txt
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// We make no guarantees that this code is fit for any purpose.
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// Visit http://OnJava8.com for more book information.
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// Holds a sequence of Objects
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interface Selector {
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boolean end();
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Object current();
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void next();
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}
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public class Sequence {
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private Object[] items;
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private int next = 0;
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public Sequence(int size) {
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items = new Object[size];
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}
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public void add(Object x) {
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if(next < items.length)
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items[next++] = x;
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}
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private class SequenceSelector implements Selector {
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private int i = 0;
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@Override
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public boolean end() { return i == items.length; }
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@Override
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public Object current() { return items[i]; }
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@Override
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public void next() { if(i < items.length) i++; }
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}
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public Selector selector() {
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return new SequenceSelector();
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}
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public static void main(String[] args) {
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Sequence sequence = new Sequence(10);
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for(int i = 0; i < 10; i++)
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sequence.add(Integer.toString(i));
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Selector selector = sequence.selector();
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while(!selector.end()) {
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System.out.print(selector.current() + " ");
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selector.next();
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}
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}
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}
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/* Output:
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0 1 2 3 4 5 6 7 8 9
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*/
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