/*******************************************************************************
* Copyright (c) 2011 - IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package com.ibm.wala.util.intset;
import java.util.NoSuchElementException;
public class EmptyIntSet implements IntSet {
public static EmptyIntSet instance = new EmptyIntSet();
@Override
public boolean contains(int i) {
return false;
}
@Override
public boolean containsAny(IntSet set) {
return false;
}
@Override
public IntSet intersection(IntSet that) {
return this;
}
@Override
public IntSet union(IntSet that) {
return that;
}
@Override
public boolean isEmpty() {
return true;
}
@Override
public int size() {
return 0;
}
private static final IntIterator emptyIter = new IntIterator() {
@Override
public boolean hasNext() {
return false;
}
@Override
public int next() {
throw new NoSuchElementException();
}
};
@Override
public IntIterator intIterator() {
return emptyIter;
}
@Override
public void foreach(IntSetAction action) {
}
@Override
public void foreachExcluding(IntSet X, IntSetAction action) {
}
@Override
public int max() {
throw new NoSuchElementException();
}
@Override
public boolean sameValue(IntSet that) {
return that.isEmpty();
}
@Override
public boolean isSubset(IntSet that) {
return true;
}
}