| /* |
| * Copyright 2003,2004 The Apache Software Foundation. |
| * |
| * 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. |
| */ |
| package org.apache.commons.functor.core.composite; |
| |
| import java.io.Serializable; |
| |
| import org.apache.commons.functor.UnaryFunction; |
| import org.apache.commons.functor.UnaryPredicate; |
| |
| /** |
| * A {@link UnaryFunction UnaryFunction} |
| * similiar to Java's "ternary" |
| * or "conditional" operator (<code>? :</code>). |
| * Given a {@link UnaryPredicate predicate} |
| * <i>p</i> and {@link UnaryFunction functions} |
| * <i>f</i> and <i>g</i>, {@link #evaluate evalautes} |
| * to |
| * <code>p.test(x) ? f.evaluate(x) : g.evaluate(x)</code>. |
| * <p> |
| * Note that although this class implements |
| * {@link Serializable}, a given instance will |
| * only be truly <code>Serializable</code> if all the |
| * underlying functors are. Attempts to serialize |
| * an instance whose delegates are not all |
| * <code>Serializable</code> will result in an exception. |
| * </p> |
| * @version $Revision$ $Date$ |
| * @author Rodney Waldhoff |
| */ |
| public final class ConditionalUnaryFunction implements UnaryFunction, Serializable { |
| |
| // constructor |
| // ------------------------------------------------------------------------ |
| |
| public ConditionalUnaryFunction(UnaryPredicate ifPred, UnaryFunction thenPred, UnaryFunction elsePred) { |
| this.ifPred = ifPred; |
| this.thenFunc = thenPred; |
| this.elseFunc = elsePred; |
| } |
| |
| // predicate interface |
| // ------------------------------------------------------------------------ |
| public Object evaluate(Object obj) { |
| return ifPred.test(obj) ? thenFunc.evaluate(obj) : elseFunc.evaluate(obj); |
| } |
| |
| public boolean equals(Object that) { |
| if(that instanceof ConditionalUnaryFunction) { |
| return equals((ConditionalUnaryFunction)that); |
| } else { |
| return false; |
| } |
| } |
| |
| public boolean equals(ConditionalUnaryFunction that) { |
| return null != that && |
| (null == ifPred ? null == that.ifPred : ifPred.equals(that.ifPred)) && |
| (null == thenFunc ? null == that.thenFunc : thenFunc.equals(that.thenFunc)) && |
| (null == elseFunc ? null == that.elseFunc : elseFunc.equals(that.elseFunc)); |
| } |
| |
| public int hashCode() { |
| int hash = "ConditionalUnaryFunction".hashCode(); |
| if(null != ifPred) { |
| hash <<= 4; |
| hash ^= ifPred.hashCode(); |
| } |
| if(null != thenFunc) { |
| hash <<= 4; |
| hash ^= thenFunc.hashCode(); |
| } |
| if(null != elseFunc) { |
| hash <<= 4; |
| hash ^= elseFunc.hashCode(); |
| } |
| return hash; |
| } |
| |
| public String toString() { |
| return "ConditionalUnaryFunction<" + ifPred + "?" + thenFunc + ":" + elseFunc + ">"; |
| } |
| |
| // attributes |
| // ------------------------------------------------------------------------ |
| private UnaryPredicate ifPred = null; |
| private UnaryFunction thenFunc = null; |
| private UnaryFunction elseFunc = null; |
| } |