/*******************************************************************************
* 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.
*
* This file is a derivative of code released by the University of
* California under the terms listed below.
*
* Refinement Analysis Tools is Copyright (c) 2007 The Regents of the
* University of California (Regents). Provided that this notice and
* the following two paragraphs are included in any distribution of
* Refinement Analysis Tools or its derivative work, Regents agrees
* not to assert any of Regents' copyright rights in Refinement
* Analysis Tools against recipient for recipient's reproduction,
* preparation of derivative works, public display, public
* performance, distribution or sublicensing of Refinement Analysis
* Tools and derivative works, in source code and object code form.
* This agreement not to assert does not confer, by implication,
* estoppel, or otherwise any license or rights in any intellectual
* property of Regents, including, but not limited to, any patents
* of Regents or Regents' employees.
*
* IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT,
* INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES,
* INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE
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* POSSIBILITY OF SUCH DAMAGE.
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* WARRANTY OF NON-INFRINGEMENT. THE SOFTWARE AND ACCOMPANYING
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*/
package com.ibm.wala.util.collections;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
* A set implementation backed by an array. This implementation is space-efficient for small sets, but several operations like
* {@link #contains(Object)} are linear time.
*
* @param <T>
*/
public class ArraySet<T> extends AbstractSet<T> {
@SuppressWarnings("rawtypes")
private static final ArraySet EMPTY = new ArraySet<Object>(0, true) {
@Override
/*
* @throws UnsupportedOperationException unconditionally
*/
public boolean add(Object obj_) {
throw new UnsupportedOperationException();
}
};
@SuppressWarnings("all")
public static final <T> ArraySet<T> empty() {
return (ArraySet<T>) EMPTY;
}
private T[] _elems;
private int _curIndex = 0;
private final boolean checkDupes;
@SuppressWarnings("all")
public ArraySet(int n, boolean checkDupes) {
if (n < 0) {
throw new IllegalArgumentException("invalid n: " + n);
}
_elems = (T[]) new Object[n];
this.checkDupes = checkDupes;
}
public ArraySet() {
this(1, true);
}
@SuppressWarnings("all")
public ArraySet(ArraySet<T> other) throws IllegalArgumentException {
if (other == null) {
throw new IllegalArgumentException("other == null");
}
int size = other._curIndex;
this._elems = (T[]) new Object[size];
this.checkDupes = other.checkDupes;
this._curIndex = size;
System.arraycopy(other._elems, 0, _elems, 0, size);
}
private ArraySet(Collection<T> other) {
this(other.size(), true);
addAll(other);
}
/**
* @throws UnsupportedOperationException if this {@link ArraySet} is immutable (optional)
*/
@SuppressWarnings("all")
public boolean add(T o) {
if (o == null) {
throw new IllegalArgumentException("null o");
}
if (checkDupes && this.contains(o)) {
return false;
}
if (_curIndex == _elems.length) {
// lengthen array
Object[] tmp = _elems;
_elems = (T[]) new Object[tmp.length * 2];
System.arraycopy(tmp, 0, _elems, 0, tmp.length);
}
_elems[_curIndex] = o;
_curIndex++;
return true;
}
public boolean addAll(ArraySet<T> other) throws IllegalArgumentException {
if (other == null) {
throw new IllegalArgumentException("other == null");
}
boolean ret = false;
for (int i = 0; i < other.size(); i++) {
boolean added = add(other.get(i));
ret = ret || added;
}
return ret;
}
/*
* @see AAA.util.AAASet#contains(java.lang.Object)
*/
@Override
public boolean contains(Object obj_) {
for (int i = 0; i < _curIndex; i++) {
if (_elems[i].equals(obj_))
return true;
}
return false;
}
public boolean intersects(ArraySet<T> other) throws IllegalArgumentException {
if (other == null) {
throw new IllegalArgumentException("other == null");
}
for (int i = 0; i < other.size(); i++) {
if (contains(other.get(i)))
return true;
}
return false;
}
public void forall(ObjectVisitor<T> visitor) {
if (visitor == null) {
throw new IllegalArgumentException("null visitor");
}
for (int i = 0; i < _curIndex; i++) {
visitor.visit(_elems[i]);
}
}
@Override
public int size() {
return _curIndex;
}
/**
* @throws IndexOutOfBoundsException if the index is out of range (index < 0 || index >= size()).
*/
public T get(int i) {
return _elems[i];
}
@Override
public boolean remove(Object obj_) {
int ind;
for (ind = 0; ind < _curIndex && !_elems[ind].equals(obj_); ind++) {
}
// check if object was never there
if (ind == _curIndex)
return false;
return remove(ind);
}
/**
* @return <code>true</code> (SJF: So why return a value?)
*/
public boolean remove(int ind) {
try {
// hope i got this right...
System.arraycopy(_elems, ind + 1, _elems, ind, _curIndex - (ind + 1));
_curIndex--;
return true;
} catch (ArrayIndexOutOfBoundsException e) {
throw new IllegalArgumentException("invalid ind: " + ind);
}
}
@Override
public void clear() {
_curIndex = 0;
}
/*
* @see java.util.Set#iterator()
*/
@Override
public Iterator<T> iterator() {
return new ArraySetIterator();
}
public class ArraySetIterator implements Iterator<T> {
int ind = 0;
final int setSize = size();
public ArraySetIterator() {
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
@Override
public boolean hasNext() {
return ind < setSize;
}
@Override
public T next() {
if (ind >= setSize) {
throw new NoSuchElementException();
}
return get(ind++);
}
}
public static <T> ArraySet<T> make() {
return new ArraySet<T>();
}
public static <T> ArraySet<T> make(Collection<T> other) throws IllegalArgumentException {
if (other == null) {
throw new IllegalArgumentException("other == null");
}
return new ArraySet<T>(other);
}
}