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 package org.apache.commons.functor.core.composite;
018
019 import java.io.Serializable;
020
021 import org.apache.commons.functor.BinaryFunction;
022 import org.apache.commons.functor.BinaryProcedure;
023 import org.apache.commons.functor.UnaryProcedure;
024
025 /**
026 * A BinaryProcedure composed of a BinaryFunction whose result is then run through a UnaryProcedure.
027 * @version $Revision: 1171154 $ $Date: 2011-09-15 17:58:38 +0200 (Thu, 15 Sep 2011) $
028 * @author Matt Benson
029 */
030 public class TransformedBinaryProcedure<L, R> implements BinaryProcedure<L, R>, Serializable {
031 /**
032 * serialVersionUID declaration.
033 */
034 private static final long serialVersionUID = -7559182250073101798L;
035
036 /**
037 * Type-remembering helper
038 * @param <X>
039 */
040 private static final class Helper<X, L, R> implements BinaryProcedure<L, R>, Serializable {
041 /**
042 * serialVersionUID declaration.
043 */
044 private static final long serialVersionUID = -4229496007094829301L;
045 private BinaryFunction<? super L, ? super R, ? extends X> function;
046 private UnaryProcedure<? super X> procedure;
047
048 /**
049 * Create a new Helper.
050 * @param function BinaryFunction
051 * @param procedure UnaryFunction
052 */
053 private Helper(BinaryFunction<? super L, ? super R, ? extends X> function,
054 UnaryProcedure<? super X> procedure) {
055 this.function = function;
056 this.procedure = procedure;
057 }
058
059 /**
060 * {@inheritDoc}
061 */
062 public void run(L left, R right) {
063 procedure.run(function.evaluate(left, right));
064 }
065 }
066
067 private final Helper<?, L, R> helper;
068
069 /**
070 * Create a new TransformedBinaryProcedure.
071 * @param <X>
072 * @param function BinaryFunction
073 * @param procedure UnaryProcedure
074 */
075 public <X> TransformedBinaryProcedure(BinaryFunction<? super L, ? super R, ? extends X> function,
076 UnaryProcedure<? super X> procedure) {
077 this.helper = new Helper<X, L, R>(function, procedure);
078 }
079
080 /**
081 * {@inheritDoc}
082 */
083 public final void run(L left, R right) {
084 helper.run(left, right);
085 }
086
087 /**
088 * {@inheritDoc}
089 */
090 @Override
091 public final boolean equals(Object obj) {
092 return obj == this || obj instanceof TransformedBinaryProcedure<?, ?>
093 && equals((TransformedBinaryProcedure<?, ?>) obj);
094 }
095
096 /**
097 * Learn whether another TransformedBinaryProcedure is equal to <code>this</code>.
098 * @param that instance to test
099 * @return whether equal
100 */
101 public final boolean equals(TransformedBinaryProcedure<?, ?> that) {
102 return that != null && that.helper.function.equals(this.helper.function)
103 && that.helper.procedure.equals(this.helper.procedure);
104 }
105
106 /**
107 * {@inheritDoc}
108 */
109 @Override
110 public int hashCode() {
111 int result = "TransformedBinaryProcedure".hashCode();
112 result <<= 2;
113 result |= helper.procedure.hashCode();
114 result <<= 2;
115 result |= helper.function.hashCode();
116 return result;
117 }
118
119 /**
120 * {@inheritDoc}
121 */
122 @Override
123 public String toString() {
124 return "TransformedBinaryProcedure<" + helper.function + "; " + helper.procedure + ">";
125 }
126 }