MappingFinder.java
/*
* *************************************************************************************************************************************************************
*
* TheseFoolishThings: Miscellaneous utilities
* http://tidalwave.it/projects/thesefoolishthings
*
* Copyright (C) 2009 - 2025 by Tidalwave s.a.s. (http://tidalwave.it)
*
* *************************************************************************************************************************************************************
*
* 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.
*
* *************************************************************************************************************************************************************
*
* git clone https://bitbucket.org/tidalwave/thesefoolishthings-src
* git clone https://github.com/tidalwave-it/thesefoolishthings-src
*
* *************************************************************************************************************************************************************
*/
package it.tidalwave.util.impl.finder;
// import javax.annotation.concurrent.Immutable;
import jakarta.annotation.Nonnull;
import java.util.List;
import java.util.function.Function;
import it.tidalwave.util.Finder;
import it.tidalwave.util.spi.SimpleFinderSupport;
import static java.util.stream.Collectors.*;
/***************************************************************************************************************************************************************
*
* A {@link it.tidalwave.util.Finder} which retrieves results from another instance applying a mapper {@link Function}. Don't use directly; use
* {@link it.tidalwave.util.Finder#mapping(Finder, Function)} instead.
*
* @param <T> the mapped type
* @param <U> the type of the delegate Finder
* @author Fabrizio Giudici
*
**************************************************************************************************************************************************************/
/* @Immutable */
public final class MappingFinder<T, U> extends SimpleFinderSupport<T>
{
private static final long serialVersionUID = -6359683808082070089L;
@Nonnull
private final Finder<? extends U> delegate;
@Nonnull
private final Function<? super U, ? extends T> mapper;
/***********************************************************************************************************************************************************
* Creates a new instance given a delegate and a mapper function.
* @param delegate the delegate
* @param mapper the mapper function
**********************************************************************************************************************************************************/
public MappingFinder (@Nonnull final Finder<? extends U> delegate, @Nonnull final Function<? super U, ? extends T> mapper)
{
this.delegate = delegate;
this.mapper = mapper;
}
/***********************************************************************************************************************************************************
* The special Finder copy constructor.
* @param other the finder to copy
* @param override the overriding object
**********************************************************************************************************************************************************/
@SuppressWarnings("unchecked")
public MappingFinder (@Nonnull final MappingFinder<T, ?> other, @Nonnull final Object override)
{
super(other, override);
final var source = getSource(MappingFinder.class, other, override);
this.delegate = source.delegate;
this.mapper = source.mapper;
}
/***********************************************************************************************************************************************************
* {@inheritDoc}
**********************************************************************************************************************************************************/
@Override @Nonnull
protected List<T> computeResults()
{
return delegate.results().stream().map(mapper).collect(toList());
}
}