/* * 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 org.cactoos.Func; import org.cactoos.Scalar; /** * Ternary operation. * * <p>There is no thread-safety guarantee. * * <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> * * <pre>{@code * new Ternary<>( * 5, * input -> input > 3, * input -> input = 8, * input -> input = 2 * ).value() // will be equal to 8 * }</pre> * * @param <T> Type of item. * @since 0.8 */ public final class Ternary<T> implements Scalar<T> { /** * The condition. */ private final Scalar<Boolean> condition; /** * The consequent. */ private final Scalar<T> consequent; /** * The alternative. */ private final Scalar<T> alternative; /** * Ctor. * @param input The input to pass to all of them * @param cnd The condition * @param cons The consequent * @param alter The alternative * @param <X> Type of input * @since 0.9 * @checkstyle ParameterNumberCheck (5 lines) */ public <X> Ternary(final X input, final Func<X, Boolean> cnd, final Func<X, T> cons, final Func<X, T> alter) { this( () -> cnd.apply(input), () -> cons.apply(input), () -> alter.apply(input) ); } /** * Ctor. * @param cnd The condition * @param cons The consequent * @param alter The alternative * @since 0.9 */ public Ternary(final boolean cnd, final T cons, final T alter) { this(() -> cnd, cons, alter); } /** * Ctor. * @param cnd The condition * @param cons The consequent * @param alter The alternative */ public Ternary(final Scalar<Boolean> cnd, final T cons, final T alter) { this(cnd, () -> cons, () -> alter); } /** * Ctor. * @param cnd The condition * @param cons The consequent * @param alter The alternative * @since 0.9 */ public Ternary(final Scalar<Boolean> cnd, final Scalar<T> cons, final Scalar<T> alter) { this.condition = cnd; this.consequent = cons; this.alternative = alter; } @Override public T value() throws Exception { final Scalar<T> result; if (this.condition.value()) { result = this.consequent; } else { result = this.alternative; } return result.value(); } }