com.helger.commons.functional.IThrowingFunction Maven / Gradle / Ivy
Show all versions of ph-commons Show documentation
/*
* Copyright (C) 2014-2024 Philip Helger (www.helger.com)
* philip[at]helger[dot]com
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.helger.commons.functional;
import java.util.Objects;
import javax.annotation.Nonnull;
/**
* Represents a function that accepts one argument and produces a result and may
* throw an Exception.
*
* This is a functional interface whose functional method is
* {@link #apply(Object)}.
*
* @param
* the type of the input to the function
* @param
* the type of the result of the function
* @param
* exception type
* @since 8.3.1
*/
@FunctionalInterface
public interface IThrowingFunction
{
/**
* Applies this function to the given argument.
*
* @param t
* the function argument
* @return the function result
* @throws EXTYPE
* In case it is needed
*/
R apply (T t) throws EXTYPE;
/**
* Returns a composed function that first applies the {@code before} function
* to its input, and then applies this function to the result. If evaluation
* of either function throws an exception, it is relayed to the caller of the
* composed function.
*
* @param
* the type of input to the {@code before} function, and to the
* composed function
* @param before
* the function to apply before this function is applied
* @return a composed function that first applies the {@code before} function
* and then applies this function
* @throws NullPointerException
* if before is null
* @see #andThen(IThrowingFunction)
*/
@Nonnull
default IThrowingFunction compose (@Nonnull final IThrowingFunction before)
{
Objects.requireNonNull (before);
return x -> apply (before.apply (x));
}
/**
* Returns a composed function that first applies this function to its input,
* and then applies the {@code after} function to the result. If evaluation of
* either function throws an exception, it is relayed to the caller of the
* composed function.
*
* @param
* the type of output of the {@code after} function, and of the
* composed function
* @param after
* the function to apply after this function is applied
* @return a composed function that first applies this function and then
* applies the {@code after} function
* @throws NullPointerException
* if after is null
* @see #compose(IThrowingFunction)
*/
@Nonnull
default IThrowingFunction andThen (@Nonnull final IThrowingFunction after)
{
Objects.requireNonNull (after);
return x -> after.apply (apply (x));
}
}