/*
* Kodkod -- Copyright (c) 2005-present, Emina Torlak
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package kodkod.util.ints;
import java.util.Arrays;
import java.util.NoSuchElementException;
/**
* An immutable set of integers, stored in a sorted array.
*
* @specfield ints: set int
* @author Emina Torlak
*/
public final class ArrayIntSet extends AbstractIntSet {
private final int[] ints;
private final int hashcode;
/**
* Constructs a set view for the given array. The array must contain no duplicates,
* its elements must be sorted
* in the ascending order, and its contents
* must not be changed while it is in use by this set
* @requires all i, j: [0..ints.length) | i < j => array[i] <= array[j]
* @ensures this.ints' = ints
*/
public ArrayIntSet(int[] ints) {
this.ints = ints;
this.hashcode = Ints.superFastHash(ints);
}
/**
* Constructs an ArrayIntSet that is <tt>equal</tt> to the
* given set.
* @ensures this.ints' = s.ints
*/
public ArrayIntSet(IntSet s) {
this(s.toArray());
}
/**
* {@inheritDoc}
* @see kodkod.util.ints.IntSet#iterator(int, int)
*/
public IntIterator iterator(final int from, final int to) {
return from <= to ? new AscendingIntArrayIterator(from,to) : new DescendingIntArrayIterator(from,to);
}
/**
* {@inheritDoc}
* @see kodkod.util.ints.IntSet#size()
*/
public int size() {
return ints.length;
}
/**
* @see kodkod.util.ints.IntSet#ceil(int)
*/
public int ceil(int i) {
final int index = Arrays.binarySearch(ints, i);
if (index==-ints.length-1) throw new NoSuchElementException();
else return index >= 0 ? ints[index] : ints[-index-1];
}
/**
* @see kodkod.util.ints.IntSet#floor(int)
*/
public int floor(int i) {
final int index = Arrays.binarySearch(ints, i);
if (index==-1) throw new NoSuchElementException();
else return index >= 0 ? ints[index] : ints[-index-2];
}
/**
* Returns true if i is in this set.
* @return i in this.ints
* @see kodkod.util.ints.IntSet#contains(int)
*/
public boolean contains(int i) {
return Arrays.binarySearch(ints, i) >= 0;
}
/**
* Returns the smallest element in this set.
* Throws a NoSuchElementException if this set is empty.
* @return min(this.ints)
* @throws java.util.NoSuchElementException no this.ints
* @see kodkod.util.ints.IntSet#max()
*/
@Override
public int max() {
if (ints.length==0) throw new NoSuchElementException();
return ints[ints.length-1];
}
/**
* Returns the largest element in this set.
* Throws a NoSuchElementException if this set is empty.
* @return max(this.ints)
* @throws java.util.NoSuchElementException no this.ints
* @see kodkod.util.ints.IntSet#min()
*/
@Override
public int min() {
if (ints.length==0) throw new NoSuchElementException();
return ints[0];
}
/**
* {@inheritDoc}
* @see kodkod.util.ints.IntCollection#toArray()
*/
@Override
public int[] toArray() {
final int[] ret = new int[ints.length];
System.arraycopy(ints, 0, ret, 0, ints.length);
return ret;
}
/**
* {@inheritDoc}
* @see kodkod.util.ints.IntCollection#toArray(int[])
*/
@Override
public int[] toArray(int[] array) {
if (array.length < size()) {
array = new int[ints.length];
}
System.arraycopy(ints, 0, array, 0, ints.length);
return array;
}
/**
* {@inheritDoc}
* @see kodkod.util.ints.IntSet#hashCode()
*/
@Override
public int hashCode() { return hashcode; }
/**
* {@inheritDoc}
* @see kodkod.util.ints.IntSet#equals(java.lang.Object)
*/
@Override
public boolean equals(Object o) {
return (o instanceof ArrayIntSet) ?
java.util.Arrays.equals(ints, ((ArrayIntSet)o).ints) :
super.equals(o);
}
/**
* An iterator that returns the elements of this int set in the
* ascending order.
* @author Emina Torlak
*/
private final class AscendingIntArrayIterator implements IntIterator {
private int next, end;
/**
* Constructs a new AscendingIntArrayIterator.
* @requires from <= to
*/
AscendingIntArrayIterator(int from, int to) {
final int fromIndex = Arrays.binarySearch(ints, from);
final int toIndex = Arrays.binarySearch(ints, to);
next = fromIndex >= 0 ? fromIndex : -fromIndex-1;
end = toIndex >=0 ? toIndex : -toIndex-2;
}
public boolean hasNext() { return next>=0 && next <= end; }
public int next() {
if (!hasNext()) throw new NoSuchElementException();
return ints[next++];
}
public final void remove() { throw new UnsupportedOperationException(); }
}
/**
* An iterator that returns the elements of this int set in the
* descending order.
* @author Emina Torlak
*/
private final class DescendingIntArrayIterator implements IntIterator {
private int next, end;
/**
* Constructs a new AscendingIntArrayIterator.
* @requires from >= to
*/
DescendingIntArrayIterator(int from, int to) {
final int fromIndex = Arrays.binarySearch(ints, from);
final int toIndex = Arrays.binarySearch(ints, to);
next = fromIndex >= 0 ? fromIndex : -fromIndex-2;
end = toIndex >=0 ? toIndex : -toIndex-1;
}
public boolean hasNext() { return next >= end; }
public int next() {
if (!hasNext()) throw new NoSuchElementException();
return ints[next--];
}
public final void remove() { throw new UnsupportedOperationException(); }
}
}