FeatureSet.java

/**
 * Copyright (c) 2009 International Health Terminology Standards Development
 * Organisation
 * 
 * Licensed 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.
 */
/**
 * Copyright CSIRO Australian e-Health Research Centre (http://aehrc.com).
 * All rights reserved. Use is subject to license terms and conditions.
 */

package au.csiro.snorocket.core.util;

import java.io.Serializable;
import java.util.BitSet;

/**
 * Stores a set of Feature indexes in the range 0..127 using the bits of two
 * longs.
 * 
 * @author Alejandro Metke
 */
final public class FeatureSet extends BitSet implements Serializable {
    
    /**
     * Serialisation version.
     */
    private static final long serialVersionUID = 1L;

    public FeatureSet() {
    }

    public FeatureSet(final FeatureSet initial) {
        or(initial);
    }

    public void add(int feature) {
        set(feature);
    }

    public void addAll(FeatureSet set) {
        or(set);
    }

    public boolean contains(int feature) {
        return get(feature);
    }

    public int first() {
        return nextSetBit(0);
    }

    public int next(int feature) {
        return nextSetBit(feature);
    }
}