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 */
017package org.apache.commons.functor.adapter;
018
019import org.apache.commons.functor.BinaryFunction;
020import org.apache.commons.functor.BinaryProcedure;
021import org.apache.commons.lang3.Validate;
022
023/**
024 * Adapts a {@link BinaryFunction BinaryFunction}
025 * to the {@link BinaryProcedure BinaryProcedure}
026 * interface by ignoring the value returned
027 * by the function.
028 *
029 * @param <L> the left argument type.
030 * @param <R> the right argument type.
031 * @version $Revision: 1537906 $ $Date: 2013-11-01 12:47:33 +0100 (Fr, 01 Nov 2013) $
032 */
033public final class BinaryFunctionBinaryProcedure<L, R> implements BinaryProcedure<L, R> {
034
035    /** The {@link BinaryFunction BinaryFunction} I'm wrapping. */
036    private final BinaryFunction<? super L, ? super R, ?> function;
037
038    /**
039     * Create an {@link BinaryProcedure BinaryProcedure} wrapping
040     * the given {@link BinaryFunction BinaryFunction}.
041     * @param function the {@link BinaryFunction BinaryFunction} to wrap
042     */
043    public BinaryFunctionBinaryProcedure(BinaryFunction<? super L, ? super R, ?> function) {
044        this.function = Validate.notNull(function, "BinaryFunction argument was null");
045    }
046
047    /**
048     * {@link BinaryFunction#evaluate Evaluate} my function, but
049     * ignore its returned value.
050     * {@inheritDoc}
051     */
052    public void run(L left, R right) {
053        function.evaluate(left, right);
054    }
055
056    /**
057     * {@inheritDoc}
058     */
059    @Override
060    public boolean equals(Object obj) {
061        if (obj == this) {
062            return true;
063        }
064        if (!(obj instanceof BinaryFunctionBinaryProcedure<?, ?>)) {
065            return false;
066        }
067        BinaryFunctionBinaryProcedure<?, ?> that = (BinaryFunctionBinaryProcedure<?, ?>) obj;
068        return this.function.equals(that.function);
069    }
070
071    /**
072     * {@inheritDoc}
073     */
074    @Override
075    public int hashCode() {
076        int hash = "BinaryFunctionBinaryProcedure".hashCode();
077        hash ^= function.hashCode();
078        return hash;
079    }
080
081    /**
082     * {@inheritDoc}
083     */
084    @Override
085    public String toString() {
086        return "BinaryFunctionBinaryProcedure<" + function + ">";
087    }
088
089    /**
090     * Adapt the given, possibly-<code>null</code>,
091     * {@link BinaryFunction BinaryFunction} to the
092     * {@link BinaryProcedure BinaryProcedure} interface.
093     * When the given <code>BinaryFunction</code> is <code>null</code>,
094     * returns <code>null</code>.
095     *
096     * @param <L> left type
097     * @param <R> right type
098     * @param function the possibly-<code>null</code>
099     *        {@link BinaryFunction BinaryFunction} to adapt
100     * @return a <code>BinaryFunctionBinaryProcedure</code> wrapping the given
101     *         {@link BinaryFunction BinaryFunction}, or <code>null</code>
102     *         if the given <code>BinaryFunction</code> is <code>null</code>
103     */
104    public static <L, R> BinaryFunctionBinaryProcedure<L, R> adapt(BinaryFunction<? super L, ? super R, ?> function) {
105        return null == function ? null : new BinaryFunctionBinaryProcedure<L, R>(function);
106    }
107
108}