repacked.com.google.common.collect.FluentIterable Maven / Gradle / Ivy
package repacked.com.google.common.collect;
import java.util.Objects;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
/**
* Copyright (C) 2010 RapidPM
* 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.
*
* Created by RapidPM - Team on 19.09.16.
*/
public abstract class FluentIterable implements Iterable {
/**
* Returns a fluent iterable that combines two iterables. The returned iterable has an iterator
* that traverses the elements in {@code a}, followed by the elements in {@code b}. The source
* iterators are not polled until necessary.
*
*
The returned iterable's iterator supports {@code remove()} when the corresponding input
* iterator supports it.
*
*
{@code Stream} equivalent: { Stream#concat}.
*
* @since 20.0
*/
public static Iterable concat(Iterable a, Iterable b) {
return Stream
.concat(
StreamSupport.stream(a.spliterator(), false),
StreamSupport.stream(b.spliterator(), false))
.collect(Collectors.toList());
// return concat(ImmutableList.of(a, b));
}
/**
* Returns a fluent iterable that combines several iterables. The returned iterable has an
* iterator that traverses the elements of each iterable in {@code inputs}. The input iterators
* are not polled until necessary.
*
*
The returned iterable's iterator supports {@code remove()} when the corresponding input
* iterator supports it. The methods of the returned iterable may throw {@code
* NullPointerException} if any of the input iterators is {@code null}.
*
*
{@code Stream} equivalent: {@code streamOfStreams.flatMap(s -> s)} or {@code
* streamOfIterables.flatMap(Streams::stream)}. (See { Streams#stream}.)
*
* @since 20.0
*/
public static Iterable concat(final Iterable> inputs) {
return StreamSupport
.stream(inputs.spliterator(), false)
.filter(Objects::nonNull)
.flatMap(itreable -> StreamSupport.stream(itreable.spliterator(), false))
.collect(Collectors.toList());
}
}