/* * The MIT License (MIT) * * Copyright (c) 2017-2020 Yegor Bugayenko * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ package org.cactoos.scalar; import java.math.BigDecimal; import java.math.MathContext; import org.cactoos.Scalar; import org.cactoos.iterable.IterableOf; import org.cactoos.iterable.Joined; import org.cactoos.iterable.Mapped; /** * Multiplication result of numbers. * * <p>Here is how you can use it to multiply numbers:</p> * * <pre> * int multiplication = new MultiplicationOf(1, 2, 3, 4).intValue(); * long multiplication = new MultiplicationOf(1L, 2L, 3L).longValue(); * double multiplication = new MultiplicationOf(2.3, 3.4, 4.0).doubleValue(); * </pre> * * <p>This class implements {@link Scalar}, which throws a checked * {@link Exception}. This may not be convenient in many cases. To make * it more convenient and get rid of the checked exception you can * use the {@link Unchecked} decorator. Or you may use * {@link IoChecked} to wrap it in an IOException.</p> * * <p>There is no thread-safety guarantee. * * @since 0.49.2 */ public final class MultiplicationOf extends NumberEnvelope { /** * Serialization marker. */ private static final long serialVersionUID = -5039588861554829762L; /** * Ctor. * @param arg Required argument * @param src The numbers */ public MultiplicationOf(final Number arg, final Number... src) { this(new Joined<>(arg, new IterableOf<>(src))); } /** * Ctor. * @param src The iterable */ public MultiplicationOf(final Iterable<? extends Number> src) { super(() -> { if (!src.iterator().hasNext()) { throw new IllegalArgumentException( "Zero arguments - can not multiply" ); } return new Folded<>( BigDecimal.ONE, (mtn, value) -> mtn.multiply(value, MathContext.DECIMAL128), new Mapped<>( number -> BigDecimal.valueOf(number.doubleValue()), src ) ).value().doubleValue(); }); } }