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 * https://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; 019 020/** 021 * A functional interface like a {@code ToBooleanFunction} that declares a {@link Throwable}. 022 * 023 * @param <T> the type of the argument to the function 024 * @param <E> The kind of thrown exception or error. 025 * @since 3.18 026 */ 027@FunctionalInterface 028public interface FailableToBooleanFunction<T, E extends Throwable> { 029 030 /** NOP singleton */ 031 @SuppressWarnings("rawtypes") 032 FailableToBooleanFunction NOP = t -> false; 033 034 /** 035 * Gets the NOP singleton. 036 * 037 * @param <T> the type of the argument to the function 038 * @param <E> The kind of thrown exception or error. 039 * @return The NOP singleton. 040 */ 041 @SuppressWarnings("unchecked") 042 static <T, E extends Throwable> FailableToBooleanFunction<T, E> nop() { 043 return NOP; 044 } 045 046 /** 047 * Applies this function to the given arguments. 048 * 049 * @param t the first function argument 050 * @return the function result 051 * @throws E Thrown when the function fails. 052 */ 053 boolean applyAsBoolean(T t) throws E; 054}