ToDoubleBiFunctionWithException.java
/**
* Powerunit - A JDK1.8 test framework
* Copyright (C) 2014 Mathieu Boretti.
*
* This file is part of Powerunit
*
* Powerunit is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Powerunit is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Powerunit. If not, see <http://www.gnu.org/licenses/>.
*/
package ch.powerunit.extensions.exceptions;
import static ch.powerunit.extensions.exceptions.Constants.verifyExceptionMapper;
import static ch.powerunit.extensions.exceptions.Constants.verifyFunction;
import java.util.function.Function;
import java.util.function.Supplier;
import java.util.function.ToDoubleBiFunction;
/**
* Represents a function that accepts two arguments, may thrown exception and
* produces a double-valued result. This is the {@code double}-producing
* primitive specialization for {@link BiFunctionWithException}.
* <h3>General contract</h3>
* <ul>
* <li><b>{@link #applyAsDouble(Object, Object) double applyAsDouble(T t, U u)
* throws E}</b> - The functional method.</li>
* <li><b>uncheck</b> - Return a {@code ToDoubleBiFunction<T, U>}</li>
* <li><b>lift</b> - Return a {@code ToDoubleBiFunction<T, U>}</li>
* <li><b>ignore</b> - Return a {@code ToDoubleBiFunction<T, U>}</li>
* </ul>
*
* @see ToDoubleBiFunction
* @param <T>
* the type of the first argument to the function
* @param <U>
* the type of the second argument the function
* @param <E>
* the type of the potential exception of the function
*/
@FunctionalInterface
public interface ToDoubleBiFunctionWithException<T, U, E extends Exception> extends
PrimitiveReturnExceptionHandlerSupport<ToDoubleBiFunction<T, U>, ToDoubleBiFunctionWithException<T, U, E>>,
DoubleDefaultValue {
/**
* Applies this function to the given arguments.
*
* @param t
* the first input argument
* @param u
* the first second argument
* @return the function result
* @throws E
* any exception
* @see ToDoubleBiFunction#applyAsDouble(Object, Object)
*/
double applyAsDouble(T t, U u) throws E;
@Override
default ToDoubleBiFunction<T, U> uncheckOrIgnore(boolean uncheck) {
return (t, u) -> {
try {
return applyAsDouble(t, u);
} catch (Exception e) {
PrimitiveReturnExceptionHandlerSupport.handleException(uncheck, e, exceptionMapper());
return defaultValue();
}
};
}
/**
* Returns a function that always throw exception.
*
* @param exceptionBuilder
* the supplier to create the exception
* @param <T>
* the type of the first argument to the function
* @param <U>
* the type of the second argument the function
* @param <E>
* the type of the exception
* @return a function that always throw exception
*/
static <T, U, E extends Exception> ToDoubleBiFunctionWithException<T, U, E> failing(Supplier<E> exceptionBuilder) {
return (t, u) -> {
throw exceptionBuilder.get();
};
}
/**
* Converts a {@code ToDoubleBiFunctionWithException} to a
* {@code ToDoubleBiFunction} that wraps exception to {@code RuntimeException}.
*
* @param function
* to be unchecked
* @param <T>
* the type of the first argument to the function
* @param <U>
* the type of the second argument the function
* @param <E>
* the type of the potential exception
* @return the unchecked function
* @see #uncheck()
* @see #unchecked(ToDoubleBiFunctionWithException, Function)
* @throws NullPointerException
* if function is null
*/
static <T, U, E extends Exception> ToDoubleBiFunction<T, U> unchecked(
ToDoubleBiFunctionWithException<T, U, E> function) {
return verifyFunction(function).uncheck();
}
/**
* Converts a {@code ToDoubleBiFunctionWithException} to a
* {@code ToDoubleBiFunction} that wraps exception to {@code RuntimeException}
* by using the provided mapping function.
*
* @param function
* the be unchecked
* @param exceptionMapper
* a function to convert the exception to the runtime exception.
* @param <T>
* the type of the first argument to the function
* @param <U>
* the type of the second argument the function
* @param <E>
* the type of the potential exception
* @return the unchecked function
* @see #uncheck()
* @see #unchecked(ToDoubleBiFunctionWithException)
* @throws NullPointerException
* if function or exception is null
*/
static <T, U, E extends Exception> ToDoubleBiFunction<T, U> unchecked(
ToDoubleBiFunctionWithException<T, U, E> function, Function<Exception, RuntimeException> exceptionMapper) {
verifyFunction(function);
verifyExceptionMapper(exceptionMapper);
return new ToDoubleBiFunctionWithException<T, U, E>() {
@Override
public double applyAsDouble(T t, U u) throws E {
return function.applyAsDouble(t, u);
}
@Override
public Function<Exception, RuntimeException> exceptionMapper() {
return exceptionMapper;
}
}.uncheck();
}
/**
* Converts a {@code ToDoubleBiFunctionWithException} to a lifted
* {@code ToDoubleBiFunction} returning {@code 0} in case of exception.
*
* @param function
* to be lifted
* @param <T>
* the type of the first argument to the function
* @param <U>
* the type of the second argument the function
* @param <E>
* the type of the potential exception
* @return the lifted function
* @see #lift()
* @throws NullPointerException
* if function is null
*/
static <T, U, E extends Exception> ToDoubleBiFunction<T, U> lifted(
ToDoubleBiFunctionWithException<T, U, E> function) {
return verifyFunction(function).lift();
}
/**
* Converts a {@code ToDoubleBiFunctionWithException} to a lifted
* {@code ToDoubleBiFunction} returning {@code 0} in case of exception.
*
* @param function
* to be lifted
* @param <T>
* the type of the first argument to the function
* @param <U>
* the type of the second argument the function
* @param <E>
* the type of the potential exception
* @return the lifted function
* @see #ignore()
* @throws NullPointerException
* if function is null
*/
static <T, U, E extends Exception> ToDoubleBiFunction<T, U> ignored(
ToDoubleBiFunctionWithException<T, U, E> function) {
return verifyFunction(function).ignore();
}
/**
* Converts a {@code ToDoubleBiFunctionWithException} to a lifted
* {@code ToDoubleBiFunction} returning a default value in case of exception.
*
* @param function
* to be lifted
* @param defaultValue
* value in case of exception
* @param <T>
* the type of the first argument to the function
* @param <U>
* the type of the second argument the function
* @param <E>
* the type of the potential exception
* @return the lifted function
* @see #ignore()
* @see #ignored(ToDoubleBiFunctionWithException)
* @throws NullPointerException
* if function is null
* @since 3.0.0
*/
static <T, U, E extends Exception> ToDoubleBiFunction<T, U> ignored(
ToDoubleBiFunctionWithException<T, U, E> function, double defaultValue) {
verifyFunction(function);
return new ToDoubleBiFunctionWithException<T, U, E>() {
@Override
public double applyAsDouble(T t, U u) throws E {
return function.applyAsDouble(t, u);
}
@Override
public double defaultValue() {
return defaultValue;
}
}.ignore();
}
}