/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
namespace Lucene.Net.Support
{
///
/// This class provides supporting methods of java.util.BitSet
/// that are not present in System.Collections.BitArray.
///
public class BitSetSupport
{
///
/// Returns the next set bit at or after index, or -1 if no such bit exists.
///
///
/// the index of bit array at which to start checking
/// the next set bit or -1
public static int NextSetBit(System.Collections.BitArray bitArray, int index)
{
while (index < bitArray.Length)
{
// if index bit is set, return it
// otherwise check next index bit
if (bitArray.Get(index))
return index;
else
index++;
}
// if no bits are set at or after index, return -1
return -1;
}
///
/// Returns the next un-set bit at or after index, or -1 if no such bit exists.
///
///
/// the index of bit array at which to start checking
/// the next set bit or -1
public static int NextClearBit(System.Collections.BitArray bitArray, int index)
{
while (index < bitArray.Length)
{
// if index bit is not set, return it
// otherwise check next index bit
if (!bitArray.Get(index))
return index;
else
index++;
}
// if no bits are set at or after index, return -1
return -1;
}
///
/// Returns the number of bits set to true in this BitSet.
///
/// The BitArray object.
/// The number of bits set to true in this BitSet.
public static int Cardinality(System.Collections.BitArray bits)
{
int count = 0;
for (int i = 0; i < bits.Count; i++)
{
if (bits[i])
count++;
}
return count;
}
}
}