001/**
002 * Powerunit - A JDK1.8 test framework
003 * Copyright (C) 2014 Mathieu Boretti.
004 *
005 * This file is part of Powerunit
006 *
007 * Powerunit is free software: you can redistribute it and/or modify
008 * it under the terms of the GNU General Public License as published by
009 * the Free Software Foundation, either version 3 of the License, or
010 * (at your option) any later version.
011 *
012 * Powerunit is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
015 * GNU General Public License for more details.
016 *
017 * You should have received a copy of the GNU General Public License
018 * along with Powerunit. If not, see <http://www.gnu.org/licenses/>.
019 */
020package ch.powerunit.extensions.exceptions;
021
022import static ch.powerunit.extensions.exceptions.Constants.verifyExceptionMapper;
023import static ch.powerunit.extensions.exceptions.Constants.verifyFunction;
024
025import java.util.function.Function;
026import java.util.function.LongBinaryOperator;
027import java.util.function.Supplier;
028
029/**
030 * Represents an operation upon two {@code long}-valued operands and producing a
031 * {@code long}-valued result which may throw exception. This is the primitive
032 * type specialization of {@link BinaryOperatorWithException} for {@code long}.
033 * <h3>General contract</h3>
034 * <ul>
035 * <li><b>{@link #applyAsLong(long, long) long applyAsLong(long left, long
036 * right) throws E}</b>&nbsp;-&nbsp;The functional method.</li>
037 * <li><b>uncheck</b>&nbsp;-&nbsp;Return a {@code LongBinaryOperator}</li>
038 * <li><b>lift</b>&nbsp;-&nbsp;Return a {@code LongBinaryOperator}</li>
039 * <li><b>ignore</b>&nbsp;-&nbsp;Return a {@code LongBinaryOperator}</li>
040 * </ul>
041 *
042 * @see LongBinaryOperator
043 * @param <E>
044 *            the type of the potential exception of the function
045 */
046@FunctionalInterface
047public interface LongBinaryOperatorWithException<E extends Exception>
048                extends PrimitiveReturnExceptionHandlerSupport<LongBinaryOperator, LongBinaryOperatorWithException<E>>,
049                LongDefaultValue {
050
051        /**
052         * Applies this operator to the given operands.
053         *
054         * @param left
055         *            the first operand
056         * @param right
057         *            the second operand
058         * @return the operator result
059         * @throws E
060         *             any exception
061         * @see LongBinaryOperator#applyAsLong(long, long)
062         */
063        long applyAsLong(long left, long right) throws E;
064
065        @Override
066        default LongBinaryOperator uncheckOrIgnore(boolean uncheck) {
067                return (left, right) -> {
068                        try {
069                                return applyAsLong(left, right);
070                        } catch (Exception e) {
071                                PrimitiveReturnExceptionHandlerSupport.handleException(uncheck, e, exceptionMapper());
072                                return defaultValue();
073                        }
074                };
075        }
076
077        /**
078         * Returns a function that always throw exception.
079         *
080         * @param exceptionBuilder
081         *            the supplier to create the exception
082         * @param <E>
083         *            the type of the exception
084         * @return a function that always throw exception
085         */
086        static <E extends Exception> LongBinaryOperatorWithException<E> failing(Supplier<E> exceptionBuilder) {
087                return (t, u) -> {
088                        throw exceptionBuilder.get();
089                };
090        }
091
092        /**
093         * Converts a {@code LongBinaryOperatorWithException} to a
094         * {@code LongBinaryOperator} that convert exception to
095         * {@code RuntimeException}.
096         *
097         * @param function
098         *            to be unchecked
099         * @param <E>
100         *            the type of the potential exception
101         * @return the unchecked function
102         * @see #uncheck()
103         * @see #unchecked(LongBinaryOperatorWithException, Function)
104         * @throws NullPointerException
105         *             if function is null
106         */
107        static <E extends Exception> LongBinaryOperator unchecked(LongBinaryOperatorWithException<E> function) {
108                return verifyFunction(function).uncheck();
109        }
110
111        /**
112         * Converts a {@code LongBinaryOperatorWithException} to a
113         * {@code LongBinaryOperator} that convert exception to {@code RuntimeException}
114         * by using the provided mapping function.
115         *
116         * @param function
117         *            the be unchecked
118         * @param exceptionMapper
119         *            a function to convert the exception to the runtime exception.
120         * @param <E>
121         *            the type of the potential exception
122         * @return the unchecked function
123         * @see #uncheck()
124         * @see #unchecked(LongBinaryOperatorWithException)
125         * @throws NullPointerException
126         *             if function or exceptionMapper is null
127         */
128        static <E extends Exception> LongBinaryOperator unchecked(LongBinaryOperatorWithException<E> function,
129                        Function<Exception, RuntimeException> exceptionMapper) {
130                verifyFunction(function);
131                verifyExceptionMapper(exceptionMapper);
132                return new LongBinaryOperatorWithException<E>() {
133
134                        @Override
135                        public long applyAsLong(long left, long right) throws E {
136                                return function.applyAsLong(left, right);
137                        }
138
139                        @Override
140                        public Function<Exception, RuntimeException> exceptionMapper() {
141                                return exceptionMapper;
142                        }
143
144                }.uncheck();
145        }
146
147        /**
148         * Converts a {@code LongBinaryOperatorWithException} to a lifted
149         * {@code LongBinaryOperator} with {@code 0} as return value in case of
150         * exception.
151         *
152         * @param function
153         *            to be lifted
154         * @param <E>
155         *            the type of the potential exception
156         * @return the lifted function
157         * @see #lift()
158         * @throws NullPointerException
159         *             if function is null
160         */
161        static <E extends Exception> LongBinaryOperator lifted(LongBinaryOperatorWithException<E> function) {
162                return verifyFunction(function).lift();
163        }
164
165        /**
166         * Converts a {@code LongBinaryOperatorWithException} to a lifted
167         * {@code LongBinaryOperator} with {@code 0} as return value in case of
168         * exception.
169         *
170         * @param function
171         *            to be lifted
172         * @param <E>
173         *            the type of the potential exception
174         * @return the lifted function
175         * @see #ignore()
176         * @throws NullPointerException
177         *             if function is null
178         */
179        static <E extends Exception> LongBinaryOperator ignored(LongBinaryOperatorWithException<E> function) {
180                return verifyFunction(function).ignore();
181        }
182
183        /**
184         * Converts a {@code LongBinaryOperatorWithException} to a lifted
185         * {@code LongBinaryOperator} with a default value as return value in case of
186         * exception.
187         *
188         * @param function
189         *            to be lifted
190         * @param defaultValue
191         *            value in case of exception
192         * @param <E>
193         *            the type of the potential exception
194         * @return the lifted function
195         * @see #ignore()
196         * @see #ignored(LongBinaryOperatorWithException)
197         * @throws NullPointerException
198         *             if function is null
199         * @since 3.0.0
200         */
201        static <E extends Exception> LongBinaryOperator ignored(LongBinaryOperatorWithException<E> function,
202                        long defaultValue) {
203                verifyFunction(function);
204                return new LongBinaryOperatorWithException<E>() {
205
206                        @Override
207                        public long applyAsLong(long left, long right) throws E {
208                                return function.applyAsLong(left, right);
209                        }
210
211                        @Override
212                        public long defaultValue() {
213                                return defaultValue;
214                        }
215
216                }.ignore();
217        }
218
219}