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662 lines
23 KiB
662 lines
23 KiB
/*
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* Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
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* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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*
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*
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*
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*
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*
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*
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*
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*
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*
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*
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*
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*
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*
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*
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*
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*
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*
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*
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*
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*
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*/
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package java.util.stream;
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import java.util.Comparator;
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import java.util.Iterator;
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import java.util.Objects;
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import java.util.Optional;
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import java.util.Spliterator;
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import java.util.Spliterators;
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import java.util.function.BiConsumer;
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import java.util.function.BiFunction;
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import java.util.function.BinaryOperator;
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import java.util.function.Consumer;
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import java.util.function.DoubleConsumer;
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import java.util.function.Function;
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import java.util.function.IntConsumer;
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import java.util.function.IntFunction;
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import java.util.function.LongConsumer;
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import java.util.function.Predicate;
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import java.util.function.Supplier;
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import java.util.function.ToDoubleFunction;
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import java.util.function.ToIntFunction;
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import java.util.function.ToLongFunction;
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/**
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* Abstract base class for an intermediate pipeline stage or pipeline source
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* stage implementing whose elements are of type {@code U}.
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*
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* @param <P_IN> type of elements in the upstream source
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* @param <P_OUT> type of elements in produced by this stage
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*
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* @since 1.8
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*/
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abstract class ReferencePipeline<P_IN, P_OUT>
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extends AbstractPipeline<P_IN, P_OUT, Stream<P_OUT>>
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implements Stream<P_OUT> {
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/**
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* Constructor for the head of a stream pipeline.
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*
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* @param source {@code Supplier<Spliterator>} describing the stream source
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* @param sourceFlags the source flags for the stream source, described in
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* {@link StreamOpFlag}
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* @param parallel {@code true} if the pipeline is parallel
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*/
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ReferencePipeline(Supplier<? extends Spliterator<?>> source,
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int sourceFlags, boolean parallel) {
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super(source, sourceFlags, parallel);
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}
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/**
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* Constructor for the head of a stream pipeline.
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*
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* @param source {@code Spliterator} describing the stream source
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* @param sourceFlags The source flags for the stream source, described in
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* {@link StreamOpFlag}
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* @param parallel {@code true} if the pipeline is parallel
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*/
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ReferencePipeline(Spliterator<?> source,
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int sourceFlags, boolean parallel) {
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super(source, sourceFlags, parallel);
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}
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/**
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* Constructor for appending an intermediate operation onto an existing
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* pipeline.
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*
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* @param upstream the upstream element source.
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*/
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ReferencePipeline(AbstractPipeline<?, P_IN, ?> upstream, int opFlags) {
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super(upstream, opFlags);
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}
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// Shape-specific methods
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@Override
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final StreamShape getOutputShape() {
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return StreamShape.REFERENCE;
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}
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@Override
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final <P_IN> Node<P_OUT> evaluateToNode(PipelineHelper<P_OUT> helper,
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Spliterator<P_IN> spliterator,
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boolean flattenTree,
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IntFunction<P_OUT[]> generator) {
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return Nodes.collect(helper, spliterator, flattenTree, generator);
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}
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@Override
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final <P_IN> Spliterator<P_OUT> wrap(PipelineHelper<P_OUT> ph,
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Supplier<Spliterator<P_IN>> supplier,
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boolean isParallel) {
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return new StreamSpliterators.WrappingSpliterator<>(ph, supplier, isParallel);
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}
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@Override
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final Spliterator<P_OUT> lazySpliterator(Supplier<? extends Spliterator<P_OUT>> supplier) {
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return new StreamSpliterators.DelegatingSpliterator<>(supplier);
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}
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@Override
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final void forEachWithCancel(Spliterator<P_OUT> spliterator, Sink<P_OUT> sink) {
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do { } while (!sink.cancellationRequested() && spliterator.tryAdvance(sink));
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}
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@Override
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final Node.Builder<P_OUT> makeNodeBuilder(long exactSizeIfKnown, IntFunction<P_OUT[]> generator) {
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return Nodes.builder(exactSizeIfKnown, generator);
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}
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// BaseStream
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@Override
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public final Iterator<P_OUT> iterator() {
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return Spliterators.iterator(spliterator());
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}
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// Stream
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// Stateless intermediate operations from Stream
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@Override
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public Stream<P_OUT> unordered() {
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if (!isOrdered())
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return this;
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return new StatelessOp<P_OUT, P_OUT>(this, StreamShape.REFERENCE, StreamOpFlag.NOT_ORDERED) {
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@Override
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Sink<P_OUT> opWrapSink(int flags, Sink<P_OUT> sink) {
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return sink;
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}
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};
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}
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@Override
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public final Stream<P_OUT> filter(Predicate<? super P_OUT> predicate) {
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Objects.requireNonNull(predicate);
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return new StatelessOp<P_OUT, P_OUT>(this, StreamShape.REFERENCE,
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StreamOpFlag.NOT_SIZED) {
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@Override
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Sink<P_OUT> opWrapSink(int flags, Sink<P_OUT> sink) {
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return new Sink.ChainedReference<P_OUT, P_OUT>(sink) {
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@Override
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public void begin(long size) {
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downstream.begin(-1);
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}
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@Override
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public void accept(P_OUT u) {
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if (predicate.test(u))
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downstream.accept(u);
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}
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};
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}
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};
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}
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@Override
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@SuppressWarnings("unchecked")
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public final <R> Stream<R> map(Function<? super P_OUT, ? extends R> mapper) {
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Objects.requireNonNull(mapper);
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return new StatelessOp<P_OUT, R>(this, StreamShape.REFERENCE,
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StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) {
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@Override
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Sink<P_OUT> opWrapSink(int flags, Sink<R> sink) {
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return new Sink.ChainedReference<P_OUT, R>(sink) {
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@Override
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public void accept(P_OUT u) {
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downstream.accept(mapper.apply(u));
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}
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};
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}
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};
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}
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@Override
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public final IntStream mapToInt(ToIntFunction<? super P_OUT> mapper) {
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Objects.requireNonNull(mapper);
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return new IntPipeline.StatelessOp<P_OUT>(this, StreamShape.REFERENCE,
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StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) {
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@Override
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Sink<P_OUT> opWrapSink(int flags, Sink<Integer> sink) {
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return new Sink.ChainedReference<P_OUT, Integer>(sink) {
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@Override
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public void accept(P_OUT u) {
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downstream.accept(mapper.applyAsInt(u));
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}
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};
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}
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};
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}
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@Override
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public final LongStream mapToLong(ToLongFunction<? super P_OUT> mapper) {
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Objects.requireNonNull(mapper);
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return new LongPipeline.StatelessOp<P_OUT>(this, StreamShape.REFERENCE,
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StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) {
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@Override
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Sink<P_OUT> opWrapSink(int flags, Sink<Long> sink) {
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return new Sink.ChainedReference<P_OUT, Long>(sink) {
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@Override
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public void accept(P_OUT u) {
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downstream.accept(mapper.applyAsLong(u));
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}
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};
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}
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};
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}
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@Override
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public final DoubleStream mapToDouble(ToDoubleFunction<? super P_OUT> mapper) {
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Objects.requireNonNull(mapper);
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return new DoublePipeline.StatelessOp<P_OUT>(this, StreamShape.REFERENCE,
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StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) {
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@Override
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Sink<P_OUT> opWrapSink(int flags, Sink<Double> sink) {
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return new Sink.ChainedReference<P_OUT, Double>(sink) {
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@Override
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public void accept(P_OUT u) {
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downstream.accept(mapper.applyAsDouble(u));
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}
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};
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}
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};
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}
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@Override
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public final <R> Stream<R> flatMap(Function<? super P_OUT, ? extends Stream<? extends R>> mapper) {
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Objects.requireNonNull(mapper);
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// We can do better than this, by polling cancellationRequested when stream is infinite
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return new StatelessOp<P_OUT, R>(this, StreamShape.REFERENCE,
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StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT | StreamOpFlag.NOT_SIZED) {
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@Override
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Sink<P_OUT> opWrapSink(int flags, Sink<R> sink) {
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return new Sink.ChainedReference<P_OUT, R>(sink) {
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@Override
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public void begin(long size) {
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downstream.begin(-1);
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}
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@Override
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public void accept(P_OUT u) {
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try (Stream<? extends R> result = mapper.apply(u)) {
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// We can do better that this too; optimize for depth=0 case and just grab spliterator and forEach it
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if (result != null)
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result.sequential().forEach(downstream);
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}
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}
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};
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}
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};
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}
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@Override
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public final IntStream flatMapToInt(Function<? super P_OUT, ? extends IntStream> mapper) {
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Objects.requireNonNull(mapper);
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// We can do better than this, by polling cancellationRequested when stream is infinite
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return new IntPipeline.StatelessOp<P_OUT>(this, StreamShape.REFERENCE,
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StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT | StreamOpFlag.NOT_SIZED) {
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@Override
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Sink<P_OUT> opWrapSink(int flags, Sink<Integer> sink) {
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return new Sink.ChainedReference<P_OUT, Integer>(sink) {
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IntConsumer downstreamAsInt = downstream::accept;
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@Override
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public void begin(long size) {
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downstream.begin(-1);
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}
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@Override
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public void accept(P_OUT u) {
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try (IntStream result = mapper.apply(u)) {
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// We can do better that this too; optimize for depth=0 case and just grab spliterator and forEach it
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if (result != null)
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result.sequential().forEach(downstreamAsInt);
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}
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}
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};
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}
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};
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}
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@Override
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public final DoubleStream flatMapToDouble(Function<? super P_OUT, ? extends DoubleStream> mapper) {
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Objects.requireNonNull(mapper);
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// We can do better than this, by polling cancellationRequested when stream is infinite
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return new DoublePipeline.StatelessOp<P_OUT>(this, StreamShape.REFERENCE,
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StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT | StreamOpFlag.NOT_SIZED) {
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@Override
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Sink<P_OUT> opWrapSink(int flags, Sink<Double> sink) {
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return new Sink.ChainedReference<P_OUT, Double>(sink) {
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DoubleConsumer downstreamAsDouble = downstream::accept;
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@Override
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public void begin(long size) {
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downstream.begin(-1);
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}
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@Override
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public void accept(P_OUT u) {
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try (DoubleStream result = mapper.apply(u)) {
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// We can do better that this too; optimize for depth=0 case and just grab spliterator and forEach it
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if (result != null)
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result.sequential().forEach(downstreamAsDouble);
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}
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}
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};
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}
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};
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}
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@Override
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public final LongStream flatMapToLong(Function<? super P_OUT, ? extends LongStream> mapper) {
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Objects.requireNonNull(mapper);
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// We can do better than this, by polling cancellationRequested when stream is infinite
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return new LongPipeline.StatelessOp<P_OUT>(this, StreamShape.REFERENCE,
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StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT | StreamOpFlag.NOT_SIZED) {
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@Override
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Sink<P_OUT> opWrapSink(int flags, Sink<Long> sink) {
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return new Sink.ChainedReference<P_OUT, Long>(sink) {
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LongConsumer downstreamAsLong = downstream::accept;
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@Override
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public void begin(long size) {
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downstream.begin(-1);
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}
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@Override
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public void accept(P_OUT u) {
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try (LongStream result = mapper.apply(u)) {
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// We can do better that this too; optimize for depth=0 case and just grab spliterator and forEach it
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if (result != null)
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result.sequential().forEach(downstreamAsLong);
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}
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}
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};
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}
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};
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}
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@Override
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public final Stream<P_OUT> peek(Consumer<? super P_OUT> action) {
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Objects.requireNonNull(action);
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return new StatelessOp<P_OUT, P_OUT>(this, StreamShape.REFERENCE,
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0) {
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@Override
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Sink<P_OUT> opWrapSink(int flags, Sink<P_OUT> sink) {
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return new Sink.ChainedReference<P_OUT, P_OUT>(sink) {
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@Override
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public void accept(P_OUT u) {
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action.accept(u);
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downstream.accept(u);
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}
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};
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}
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};
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}
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// Stateful intermediate operations from Stream
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@Override
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public final Stream<P_OUT> distinct() {
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return DistinctOps.makeRef(this);
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}
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@Override
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public final Stream<P_OUT> sorted() {
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return SortedOps.makeRef(this);
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}
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@Override
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public final Stream<P_OUT> sorted(Comparator<? super P_OUT> comparator) {
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return SortedOps.makeRef(this, comparator);
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}
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@Override
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public final Stream<P_OUT> limit(long maxSize) {
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if (maxSize < 0)
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throw new IllegalArgumentException(Long.toString(maxSize));
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return SliceOps.makeRef(this, 0, maxSize);
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}
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@Override
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public final Stream<P_OUT> skip(long n) {
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if (n < 0)
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throw new IllegalArgumentException(Long.toString(n));
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if (n == 0)
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return this;
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else
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return SliceOps.makeRef(this, n, -1);
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}
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// Terminal operations from Stream
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@Override
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public void forEach(Consumer<? super P_OUT> action) {
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evaluate(ForEachOps.makeRef(action, false));
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}
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@Override
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public void forEachOrdered(Consumer<? super P_OUT> action) {
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evaluate(ForEachOps.makeRef(action, true));
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}
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@Override
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@SuppressWarnings("unchecked")
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public final <A> A[] toArray(IntFunction<A[]> generator) {
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// Since A has no relation to U (not possible to declare that A is an upper bound of U)
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// there will be no static type checking.
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// Therefore use a raw type and assume A == U rather than propagating the separation of A and U
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// throughout the code-base.
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// The runtime type of U is never checked for equality with the component type of the runtime type of A[].
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// Runtime checking will be performed when an element is stored in A[], thus if A is not a
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// super type of U an ArrayStoreException will be thrown.
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@SuppressWarnings("rawtypes")
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IntFunction rawGenerator = (IntFunction) generator;
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return (A[]) Nodes.flatten(evaluateToArrayNode(rawGenerator), rawGenerator)
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.asArray(rawGenerator);
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}
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@Override
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public final Object[] toArray() {
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return toArray(Object[]::new);
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}
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@Override
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public final boolean anyMatch(Predicate<? super P_OUT> predicate) {
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return evaluate(MatchOps.makeRef(predicate, MatchOps.MatchKind.ANY));
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}
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@Override
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public final boolean allMatch(Predicate<? super P_OUT> predicate) {
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return evaluate(MatchOps.makeRef(predicate, MatchOps.MatchKind.ALL));
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}
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@Override
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public final boolean noneMatch(Predicate<? super P_OUT> predicate) {
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return evaluate(MatchOps.makeRef(predicate, MatchOps.MatchKind.NONE));
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}
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@Override
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public final Optional<P_OUT> findFirst() {
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return evaluate(FindOps.makeRef(true));
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}
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@Override
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public final Optional<P_OUT> findAny() {
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return evaluate(FindOps.makeRef(false));
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}
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@Override
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public final P_OUT reduce(final P_OUT identity, final BinaryOperator<P_OUT> accumulator) {
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return evaluate(ReduceOps.makeRef(identity, accumulator, accumulator));
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}
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@Override
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public final Optional<P_OUT> reduce(BinaryOperator<P_OUT> accumulator) {
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return evaluate(ReduceOps.makeRef(accumulator));
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}
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@Override
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public final <R> R reduce(R identity, BiFunction<R, ? super P_OUT, R> accumulator, BinaryOperator<R> combiner) {
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return evaluate(ReduceOps.makeRef(identity, accumulator, combiner));
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}
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@Override
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@SuppressWarnings("unchecked")
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public final <R, A> R collect(Collector<? super P_OUT, A, R> collector) {
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A container;
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if (isParallel()
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&& (collector.characteristics().contains(Collector.Characteristics.CONCURRENT))
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&& (!isOrdered() || collector.characteristics().contains(Collector.Characteristics.UNORDERED))) {
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container = collector.supplier().get();
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BiConsumer<A, ? super P_OUT> accumulator = collector.accumulator();
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forEach(u -> accumulator.accept(container, u));
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}
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else {
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container = evaluate(ReduceOps.makeRef(collector));
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}
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return collector.characteristics().contains(Collector.Characteristics.IDENTITY_FINISH)
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? (R) container
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: collector.finisher().apply(container);
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}
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@Override
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public final <R> R collect(Supplier<R> supplier,
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BiConsumer<R, ? super P_OUT> accumulator,
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BiConsumer<R, R> combiner) {
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return evaluate(ReduceOps.makeRef(supplier, accumulator, combiner));
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}
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@Override
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public final Optional<P_OUT> max(Comparator<? super P_OUT> comparator) {
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return reduce(BinaryOperator.maxBy(comparator));
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}
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@Override
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public final Optional<P_OUT> min(Comparator<? super P_OUT> comparator) {
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return reduce(BinaryOperator.minBy(comparator));
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}
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@Override
|
|
public final long count() {
|
|
return mapToLong(e -> 1L).sum();
|
|
}
|
|
|
|
|
|
//
|
|
|
|
/**
|
|
* Source stage of a ReferencePipeline.
|
|
*
|
|
* @param <E_IN> type of elements in the upstream source
|
|
* @param <E_OUT> type of elements in produced by this stage
|
|
* @since 1.8
|
|
*/
|
|
static class Head<E_IN, E_OUT> extends ReferencePipeline<E_IN, E_OUT> {
|
|
/**
|
|
* Constructor for the source stage of a Stream.
|
|
*
|
|
* @param source {@code Supplier<Spliterator>} describing the stream
|
|
* source
|
|
* @param sourceFlags the source flags for the stream source, described
|
|
* in {@link StreamOpFlag}
|
|
*/
|
|
Head(Supplier<? extends Spliterator<?>> source,
|
|
int sourceFlags, boolean parallel) {
|
|
super(source, sourceFlags, parallel);
|
|
}
|
|
|
|
/**
|
|
* Constructor for the source stage of a Stream.
|
|
*
|
|
* @param source {@code Spliterator} describing the stream source
|
|
* @param sourceFlags the source flags for the stream source, described
|
|
* in {@link StreamOpFlag}
|
|
*/
|
|
Head(Spliterator<?> source,
|
|
int sourceFlags, boolean parallel) {
|
|
super(source, sourceFlags, parallel);
|
|
}
|
|
|
|
@Override
|
|
final boolean opIsStateful() {
|
|
throw new UnsupportedOperationException();
|
|
}
|
|
|
|
@Override
|
|
final Sink<E_IN> opWrapSink(int flags, Sink<E_OUT> sink) {
|
|
throw new UnsupportedOperationException();
|
|
}
|
|
|
|
// Optimized sequential terminal operations for the head of the pipeline
|
|
|
|
@Override
|
|
public void forEach(Consumer<? super E_OUT> action) {
|
|
if (!isParallel()) {
|
|
sourceStageSpliterator().forEachRemaining(action);
|
|
}
|
|
else {
|
|
super.forEach(action);
|
|
}
|
|
}
|
|
|
|
@Override
|
|
public void forEachOrdered(Consumer<? super E_OUT> action) {
|
|
if (!isParallel()) {
|
|
sourceStageSpliterator().forEachRemaining(action);
|
|
}
|
|
else {
|
|
super.forEachOrdered(action);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Base class for a stateless intermediate stage of a Stream.
|
|
*
|
|
* @param <E_IN> type of elements in the upstream source
|
|
* @param <E_OUT> type of elements in produced by this stage
|
|
* @since 1.8
|
|
*/
|
|
abstract static class StatelessOp<E_IN, E_OUT>
|
|
extends ReferencePipeline<E_IN, E_OUT> {
|
|
/**
|
|
* Construct a new Stream by appending a stateless intermediate
|
|
* operation to an existing stream.
|
|
*
|
|
* @param upstream The upstream pipeline stage
|
|
* @param inputShape The stream shape for the upstream pipeline stage
|
|
* @param opFlags Operation flags for the new stage
|
|
*/
|
|
StatelessOp(AbstractPipeline<?, E_IN, ?> upstream,
|
|
StreamShape inputShape,
|
|
int opFlags) {
|
|
super(upstream, opFlags);
|
|
assert upstream.getOutputShape() == inputShape;
|
|
}
|
|
|
|
@Override
|
|
final boolean opIsStateful() {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Base class for a stateful intermediate stage of a Stream.
|
|
*
|
|
* @param <E_IN> type of elements in the upstream source
|
|
* @param <E_OUT> type of elements in produced by this stage
|
|
* @since 1.8
|
|
*/
|
|
abstract static class StatefulOp<E_IN, E_OUT>
|
|
extends ReferencePipeline<E_IN, E_OUT> {
|
|
/**
|
|
* Construct a new Stream by appending a stateful intermediate operation
|
|
* to an existing stream.
|
|
* @param upstream The upstream pipeline stage
|
|
* @param inputShape The stream shape for the upstream pipeline stage
|
|
* @param opFlags Operation flags for the new stage
|
|
*/
|
|
StatefulOp(AbstractPipeline<?, E_IN, ?> upstream,
|
|
StreamShape inputShape,
|
|
int opFlags) {
|
|
super(upstream, opFlags);
|
|
assert upstream.getOutputShape() == inputShape;
|
|
}
|
|
|
|
@Override
|
|
final boolean opIsStateful() {
|
|
return true;
|
|
}
|
|
|
|
@Override
|
|
abstract <P_IN> Node<E_OUT> opEvaluateParallel(PipelineHelper<E_OUT> helper,
|
|
Spliterator<P_IN> spliterator,
|
|
IntFunction<E_OUT[]> generator);
|
|
}
|
|
}
|