| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| ConditionalFunction |
|
| 4.0;4 |
| 1 | /* | |
| 2 | * Licensed to the Apache Software Foundation (ASF) under one or more | |
| 3 | * contributor license agreements. See the NOTICE file distributed with | |
| 4 | * this work for additional information regarding copyright ownership. | |
| 5 | * The ASF licenses this file to You under the Apache License, Version 2.0 | |
| 6 | * (the "License"); you may not use this file except in compliance with | |
| 7 | * the License. You may obtain a copy of the License at | |
| 8 | * | |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 | |
| 10 | * | |
| 11 | * Unless required by applicable law or agreed to in writing, software | |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, | |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| 14 | * See the License for the specific language governing permissions and | |
| 15 | * limitations under the License. | |
| 16 | */ | |
| 17 | package org.apache.commons.functor.core.composite; | |
| 18 | ||
| 19 | import java.io.Serializable; | |
| 20 | ||
| 21 | import org.apache.commons.functor.Function; | |
| 22 | import org.apache.commons.functor.Predicate; | |
| 23 | ||
| 24 | /** | |
| 25 | * A {@link Function Function} | |
| 26 | * similiar to Java's "ternary" | |
| 27 | * or "conditional" operator (<code>? :</code>). | |
| 28 | * Given a {@link Predicate predicate} | |
| 29 | * <i>p</i> and {@link Function functions} | |
| 30 | * <i>f</i> and <i>g</i>, {@link #evaluate evaluates} | |
| 31 | * to | |
| 32 | * <code>p.test() ? f.evaluate() : g.evaluate()</code>. | |
| 33 | * <p> | |
| 34 | * Note that although this class implements | |
| 35 | * {@link Serializable}, a given instance will | |
| 36 | * only be truly <code>Serializable</code> if all the | |
| 37 | * underlying functors are. Attempts to serialize | |
| 38 | * an instance whose delegates are not all | |
| 39 | * <code>Serializable</code> will result in an exception. | |
| 40 | * </p> | |
| 41 | * @version $Revision: 1166386 $ $Date: 2011-09-07 22:28:01 +0200 (Wed, 07 Sep 2011) $ | |
| 42 | * @author Rodney Waldhoff | |
| 43 | */ | |
| 44 | public final class ConditionalFunction<T> implements Function<T>, Serializable { | |
| 45 | /** | |
| 46 | * serialVersionUID declaration. | |
| 47 | */ | |
| 48 | private static final long serialVersionUID = 4214871352184887792L; | |
| 49 | ||
| 50 | /** Base hash integer used to shift hash */ | |
| 51 | private static final int HASH_SHIFT = 4; | |
| 52 | // attributes | |
| 53 | // ------------------------------------------------------------------------ | |
| 54 | private final Predicate ifPred; | |
| 55 | private final Function<? extends T> thenFunc; | |
| 56 | private final Function<? extends T> elseFunc; | |
| 57 | ||
| 58 | // constructor | |
| 59 | // ------------------------------------------------------------------------ | |
| 60 | /** | |
| 61 | * Create a new ConditionalFunction. | |
| 62 | * @param ifPred if | |
| 63 | * @param thenFunc then | |
| 64 | * @param elseFunc else | |
| 65 | */ | |
| 66 | 20 | public ConditionalFunction(Predicate ifPred, Function<? extends T> thenFunc, Function<? extends T> elseFunc) { |
| 67 | 20 | if (ifPred == null) { |
| 68 | 0 | throw new IllegalArgumentException("Predicate argument was null"); |
| 69 | } | |
| 70 | 20 | this.ifPred = ifPred; |
| 71 | 20 | if (thenFunc == null || elseFunc == null) { |
| 72 | 0 | throw new IllegalArgumentException("One or more Function arguments was null"); |
| 73 | } | |
| 74 | 20 | this.thenFunc = thenFunc; |
| 75 | 20 | this.elseFunc = elseFunc; |
| 76 | 20 | } |
| 77 | ||
| 78 | // predicate interface | |
| 79 | // ------------------------------------------------------------------------ | |
| 80 | /** | |
| 81 | * {@inheritDoc} | |
| 82 | */ | |
| 83 | public T evaluate() { | |
| 84 | 4 | if (ifPred.test()) { |
| 85 | 2 | return thenFunc.evaluate(); |
| 86 | } else { | |
| 87 | 2 | return elseFunc.evaluate(); |
| 88 | } | |
| 89 | } | |
| 90 | ||
| 91 | /** | |
| 92 | * {@inheritDoc} | |
| 93 | */ | |
| 94 | public boolean equals(Object that) { | |
| 95 | 24 | return that == this || (that instanceof ConditionalFunction<?> && equals((ConditionalFunction<?>) that)); |
| 96 | } | |
| 97 | ||
| 98 | /** | |
| 99 | * Learn whether another ConditionalFunction is equal to this. | |
| 100 | * @param that ConditionalFunction to test | |
| 101 | * @return boolean | |
| 102 | */ | |
| 103 | public boolean equals(ConditionalFunction<?> that) { | |
| 104 | 18 | return null != that |
| 105 | && (null == ifPred ? null == that.ifPred : ifPred.equals(that.ifPred)) | |
| 106 | && (null == thenFunc ? null == that.thenFunc : thenFunc.equals(that.thenFunc)) | |
| 107 | && (null == elseFunc ? null == that.elseFunc : elseFunc.equals(that.elseFunc)); | |
| 108 | } | |
| 109 | ||
| 110 | /** | |
| 111 | * {@inheritDoc} | |
| 112 | */ | |
| 113 | public int hashCode() { | |
| 114 | 26 | int hash = "ConditionalFunction".hashCode(); |
| 115 | 26 | if (null != ifPred) { |
| 116 | 26 | hash <<= HASH_SHIFT; |
| 117 | 26 | hash ^= ifPred.hashCode(); |
| 118 | } | |
| 119 | 26 | if (null != thenFunc) { |
| 120 | 26 | hash <<= HASH_SHIFT; |
| 121 | 26 | hash ^= thenFunc.hashCode(); |
| 122 | } | |
| 123 | 26 | if (null != elseFunc) { |
| 124 | 26 | hash <<= HASH_SHIFT; |
| 125 | 26 | hash ^= elseFunc.hashCode(); |
| 126 | } | |
| 127 | 26 | return hash; |
| 128 | } | |
| 129 | ||
| 130 | /** | |
| 131 | * {@inheritDoc} | |
| 132 | */ | |
| 133 | public String toString() { | |
| 134 | 18 | return "ConditionalFunction<" + ifPred + "?" + thenFunc + ":" + elseFunc + ">"; |
| 135 | } | |
| 136 | ||
| 137 | } |