/*

  * Licensed to the Apache Software Foundation (ASF) under one or more

  * contributor license agreements.  See the NOTICE file distributed with

  * this work for additional information regarding copyright ownership.

  * The ASF licenses this file to You 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.adapter;

 import java.io.Serializable;

 import org.apache.commons.functor.BinaryFunction;

 import org.apache.commons.functor.BinaryProcedure;

 /**

  * Adapts a {@link BinaryFunction BinaryFunction}

  * to the {@link BinaryProcedure BinaryProcedure}

  * interface by ignoring the value returned

  * by the function.

  * <p/>

  * Note that although this class implements

  * {@link Serializable}, a given instance will

  * only be truly <code>Serializable</code> if the

  * underlying function is.  Attempts to serialize

  * an instance whose delegate is not

  * <code>Serializable</code> will result in an exception.

  *

  * @param <L> the left argument type.

  * @param <R> the right argument type.

  * @version $Revision: 1156760 $ $Date: 2011-08-11 21:34:07 +0200 (Thu, 11 Aug 2011) $

  * @author Rodney Waldhoff

  */

 public final class BinaryFunctionBinaryProcedure<L, R> implements BinaryProcedure<L, R>, Serializable {

     /**

      * serialVersionUID declaration.

      */

     private static final long serialVersionUID = 4498276997127058865L;

     /** The {@link BinaryFunction BinaryFunction} I'm wrapping. */

     private final BinaryFunction<? super L, ? super R, ?> function;

     /**

      * Create an {@link BinaryProcedure BinaryProcedure} wrapping

      * the given {@link BinaryFunction BinaryFunction}.

      * @param function the {@link BinaryFunction BinaryFunction} to wrap

      */

     public BinaryFunctionBinaryProcedure(BinaryFunction<? super L, ? super R, ?> function) {

         this.function = function;

     }

     /**

      * {@link BinaryFunction#evaluate Evaluate} my function, but

      * ignore its returned value.

      * {@inheritDoc}

      */

     public void run(L left, R right) {

         function.evaluate(left, right);

     }

     /**

      * {@inheritDoc}

      */

     public boolean equals(Object that) {

         return that == this

                 || (that instanceof BinaryFunctionBinaryProcedure<?, ?>

                 && equals((BinaryFunctionBinaryProcedure<?, ?>) that));

     }

     /**

      * Learn whether a given BinaryFunctionBinaryPredicate is equal to this.

      * @param that BinaryFunctionBinaryPredicate to compare

      * @return boolean

      */

     public boolean equals(BinaryFunctionBinaryProcedure<?, ?> that) {

         return null != that && (null == function ? null == that.function : function.equals(that.function));

     }

     /**

      * {@inheritDoc}

      */

     public int hashCode() {

         int hash = "BinaryFunctionBinaryProcedure".hashCode();

         if (null != function) {

             hash ^= function.hashCode();

         }

         return hash;

     }

     /**

      * {@inheritDoc}

      */

     public String toString() {

         return "BinaryFunctionBinaryProcedure<" + function + ">";

     }

     /**

      * Adapt the given, possibly-<code>null</code>,

      * {@link BinaryFunction BinaryFunction} to the

      * {@link BinaryProcedure BinaryProcedure} interface.

      * When the given <code>BinaryFunction</code> is <code>null</code>,

      * returns <code>null</code>.

      *

      * @param <L> left type

      * @param <R> right type

      * @param function the possibly-<code>null</code>

      *        {@link BinaryFunction BinaryFunction} to adapt

      * @return a <code>BinaryFunctionBinaryProcedure</code> wrapping the given

      *         {@link BinaryFunction BinaryFunction}, or <code>null</code>

      *         if the given <code>BinaryFunction</code> is <code>null</code>

      */

     public static <L, R> BinaryFunctionBinaryProcedure<L, R> adapt(BinaryFunction<? super L, ? super R, ?> function) {

         return null == function ? null : new BinaryFunctionBinaryProcedure<L, R>(function);

     }

 }