com.google.gwt.emul.java.util.stream.StreamSupport Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of gwt-user Show documentation
There is a newer version: 2.10.0
/*
 * Copyright 2016 Google Inc.
 *
 * 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 java.util.stream;

import java.util.Spliterator;
import java.util.function.Supplier;

/**
 * See 
 * the official Java API doc for details.
 */
public final class StreamSupport {

  public static DoubleStream doubleStream(Spliterator.OfDouble spliterator, boolean parallel) {
    return new DoubleStream.DoubleStreamSource(null, spliterator);
  }

  public static DoubleStream doubleStream(
      Supplier supplier, int characteristics, boolean parallel) {
    // TODO this is somewhat convoluted, and would be better served by a lazy singleton spliterator
    return Stream.of(supplier)
        .map(Supplier::get)
        .flatMapToDouble(
            doubleSpliterator -> {
              return doubleStream(doubleSpliterator, parallel);
            });
  }

  public static IntStream intStream(Spliterator.OfInt spliterator, boolean parallel) {
    return new IntStream.IntStreamSource(null, spliterator);
  }

  public static IntStream intStream(
      Supplier supplier, int characteristics, boolean parallel) {
    // TODO this is somewhat convoluted, and would be better served by a lazy singleton spliterator
    return Stream.of(supplier)
        .map(Supplier::get)
        .flatMapToInt(
            intSpliterator -> {
              return intStream(intSpliterator, parallel);
            });
  }

  public static LongStream longStream(Spliterator.OfLong spliterator, boolean parallel) {
    return new LongStream.LongStreamSource(null, spliterator);
  }

  public static LongStream longStream(
      Supplier supplier,
      int characteristics,
      final boolean parallel) {
    // TODO this is somewhat convoluted, and would be better served by a lazy singleton spliterator
    return Stream.of(supplier)
        .map(Supplier::get)
        .flatMapToLong(
            longSpliterator -> {
              return longStream(longSpliterator, parallel);
            });
  }

  public static  Stream stream(Spliterator spliterator, boolean parallel) {
    return new Stream.StreamSource(null, spliterator);
  }

  public static  Stream stream(
      Supplier> supplier, int characteristics, final boolean parallel) {
    // TODO this is somewhat convoluted, and would be better served by a lazy singleton spliterator
    return Stream.of(supplier)
        .map(Supplier::get)
        .flatMap(
            spliterator -> {
              return stream(spliterator, parallel);
            });
  }

  private StreamSupport() {
    // prevent instantiation
  }
}