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 */
017
018package org.apache.commons.lang3.function;
019
020import java.util.function.IntToDoubleFunction;
021
022/**
023 * A functional interface like {@link IntToDoubleFunction} that declares a {@link Throwable}.
024 *
025 * @param <E> The kind of thrown exception or error.
026 * @since 3.11
027 */
028@FunctionalInterface
029public interface FailableIntToDoubleFunction<E extends Throwable> {
030
031    /** NOP singleton */
032    @SuppressWarnings("rawtypes")
033    FailableIntToDoubleFunction NOP = t -> 0d;
034
035    /**
036     * Returns The NOP singleton.
037     *
038     * @param <E> The kind of thrown exception or error.
039     * @return The NOP singleton.
040     */
041    @SuppressWarnings("unchecked")
042    static <E extends Throwable> FailableIntToDoubleFunction<E> nop() {
043        return NOP;
044    }
045
046    /**
047     * Applies this function to the given argument.
048     *
049     * @param value the function argument
050     * @return the function result
051     * @throws E Thrown when the function fails.
052     */
053    double applyAsDouble(int value) throws E;
054}