001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.math3.complex;
019
020import java.io.Serializable;
021
022import org.apache.commons.math3.Field;
023import org.apache.commons.math3.FieldElement;
024
025/**
026 * Representation of the complex numbers field.
027 * <p>
028 * This class is a singleton.
029 * </p>
030 * @see Complex
031 * @version $Id: ComplexField.java 1416643 2012-12-03 19:37:14Z tn $
032 * @since 2.0
033 */
034public class ComplexField implements Field<Complex>, Serializable  {
035
036    /** Serializable version identifier. */
037    private static final long serialVersionUID = -6130362688700788798L;
038
039    /** Private constructor for the singleton.
040     */
041    private ComplexField() {
042    }
043
044    /** Get the unique instance.
045     * @return the unique instance
046     */
047    public static ComplexField getInstance() {
048        return LazyHolder.INSTANCE;
049    }
050
051    /** {@inheritDoc} */
052    public Complex getOne() {
053        return Complex.ONE;
054    }
055
056    /** {@inheritDoc} */
057    public Complex getZero() {
058        return Complex.ZERO;
059    }
060
061    /** {@inheritDoc} */
062    public Class<? extends FieldElement<Complex>> getRuntimeClass() {
063        return Complex.class;
064    }
065
066    // CHECKSTYLE: stop HideUtilityClassConstructor
067    /** Holder for the instance.
068     * <p>We use here the Initialization On Demand Holder Idiom.</p>
069     */
070    private static class LazyHolder {
071        /** Cached field instance. */
072        private static final ComplexField INSTANCE = new ComplexField();
073    }
074    // CHECKSTYLE: resume HideUtilityClassConstructor
075
076    /** Handle deserialization of the singleton.
077     * @return the singleton instance
078     */
079    private Object readResolve() {
080        // return the singleton instance
081        return LazyHolder.INSTANCE;
082    }
083
084}