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/*
* Copyright (C) 2016, 2017, 2018, 2019 HaiYang Li
*
* 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
*
* https://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.landawn.abacus.util.stream;
import java.math.BigInteger;
import java.nio.LongBuffer;
import java.security.SecureRandom;
import java.util.Arrays;
import java.util.Collection;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.LongSummaryStatistics;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.PrimitiveIterator;
import java.util.Random;
import java.util.concurrent.TimeUnit;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
import java.util.function.BiPredicate;
import java.util.function.BinaryOperator;
import java.util.function.BooleanSupplier;
import java.util.function.Function;
import java.util.function.LongBinaryOperator;
import java.util.function.LongConsumer;
import java.util.function.LongFunction;
import java.util.function.LongPredicate;
import java.util.function.LongSupplier;
import java.util.function.LongToDoubleFunction;
import java.util.function.LongToIntFunction;
import java.util.function.LongUnaryOperator;
import java.util.function.ObjLongConsumer;
import java.util.function.Supplier;
import java.util.stream.Collector;
import com.landawn.abacus.annotation.Beta;
import com.landawn.abacus.annotation.IntermediateOp;
import com.landawn.abacus.annotation.LazyEvaluation;
import com.landawn.abacus.annotation.ParallelSupported;
import com.landawn.abacus.annotation.SequentialOnly;
import com.landawn.abacus.annotation.TerminalOp;
import com.landawn.abacus.util.Array;
import com.landawn.abacus.util.Fn.BiConsumers;
import com.landawn.abacus.util.Fn.FL;
import com.landawn.abacus.util.IndexedLong;
import com.landawn.abacus.util.LongIterator;
import com.landawn.abacus.util.LongList;
import com.landawn.abacus.util.MergeResult;
import com.landawn.abacus.util.N;
import com.landawn.abacus.util.Pair;
import com.landawn.abacus.util.Percentage;
import com.landawn.abacus.util.Throwables;
import com.landawn.abacus.util.cs;
import com.landawn.abacus.util.u.Optional;
import com.landawn.abacus.util.u.OptionalDouble;
import com.landawn.abacus.util.u.OptionalLong;
import com.landawn.abacus.util.function.LongBiFunction;
import com.landawn.abacus.util.function.LongBiPredicate;
import com.landawn.abacus.util.function.LongMapMultiConsumer;
import com.landawn.abacus.util.function.LongNFunction;
import com.landawn.abacus.util.function.LongTernaryOperator;
import com.landawn.abacus.util.function.LongToFloatFunction;
import com.landawn.abacus.util.function.LongTriPredicate;
import com.landawn.abacus.util.function.ToLongFunction;
import com.landawn.abacus.util.function.TriFunction;
/**
* The LongStream class is an abstract class that represents a stream of long elements and supports different kinds of computations.
* The Stream operations are divided into intermediate and terminal operations, and are combined to form stream pipelines.
*
*
* The Stream will be automatically closed after a terminal method is called/triggered.
*
*
*
* Refer to {@code com.landawn.abacus.util.stream.BaseStream} and {@code com.landawn.abacus.util.stream.Stream} for more APIs docs.
*
* @see com.landawn.abacus.util.stream.Stream
* @see com.landawn.abacus.util.stream.BaseStream
*/
@com.landawn.abacus.annotation.Immutable
@LazyEvaluation
public abstract class LongStream extends StreamBase {
static final Random RAND = new SecureRandom();
LongStream(final boolean sorted, final Collection closeHandlers) {
super(sorted, null, closeHandlers);
}
/**
*
* @param mapper
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract LongStream map(LongUnaryOperator mapper);
/**
*
* @param mapper
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract IntStream mapToInt(LongToIntFunction mapper);
/**
*
* @param mapper
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract FloatStream mapToFloat(LongToFloatFunction mapper);
/**
*
* @param mapper
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract DoubleStream mapToDouble(LongToDoubleFunction mapper);
/**
*
* @param
* @param mapper
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract Stream mapToObj(LongFunction mapper);
/**
*
* @param mapper
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract LongStream flatMap(LongFunction mapper);
// public abstract LongStream flatmap(LongFunction mapper);
/**
*
* @param mapper
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract LongStream flatmap(LongFunction mapper); //NOSONAR
/**
*
* @param mapper
* @return
* @deprecated should use {@code flatmapToObj(LongFunction> mapper)} instead
* @see #flatmapToObj(LongFunction)
*/
@Deprecated
@ParallelSupported
@IntermediateOp
LongStream flattMap(@SuppressWarnings("unused") final LongFunction> mapper) throws UnsupportedOperationException { // NOSONAR
throw new UnsupportedOperationException();
}
/**
*
* @param mapper
* @return
*/
@Beta
@ParallelSupported
@IntermediateOp
public abstract LongStream flattmap(LongFunction mapper); //NOSONAR
/**
*
* @param mapper
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract IntStream flatMapToInt(LongFunction mapper);
/**
*
* @param mapper
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract FloatStream flatMapToFloat(LongFunction mapper);
/**
*
* @param mapper
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract DoubleStream flatMapToDouble(LongFunction mapper);
/**
*
* @param
* @param mapper
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract Stream flatMapToObj(LongFunction> mapper);
/**
*
* @param
* @param mapper
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract Stream flatmapToObj(LongFunction> mapper); //NOSONAR
/**
*
* @param
* @param mapper
* @return
*/
@Beta
@ParallelSupported
@IntermediateOp
public abstract Stream flattMapToObj(LongFunction mapper);
/**
*
* @param mapper
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract LongStream mapMulti(LongMapMultiConsumer mapper);
/**
* Note: copied from StreamEx: StreamEx
*
* @param mapper
* @return
*/
@Beta
@ParallelSupported
@IntermediateOp
public abstract LongStream mapPartial(LongFunction mapper);
/**
* Note: copied from StreamEx: StreamEx
*
* @param mapper
* @return
*/
@Beta
@ParallelSupported
@IntermediateOp
public abstract LongStream mapPartialJdk(LongFunction mapper);
/**
* Note: copied from StreamEx: StreamEx
*
*
* Returns a stream consisting of results of applying the given function to
* the ranges created from the source elements.
* This is a quasi-intermediate
* partial reduction operation.
*
* @param sameRange a non-interfering, stateless predicate to apply to
* the leftmost and next elements which returns {@code true} for elements
* which belong to the same range.
* @param mapper a non-interfering, stateless function to apply to the
* range borders and produce the resulting element. If the value was
* not merged to the interval, then mapper will receive the same
* value twice, otherwise it will receive the leftmost and the
* rightmost values which were merged to the range.
* @return
* @see #collapse(LongBiPredicate, LongBinaryOperator)
* @see Stream#rangeMap(BiPredicate, BiFunction)
*/
@SequentialOnly
@IntermediateOp
public abstract LongStream rangeMap(final LongBiPredicate sameRange, final LongBinaryOperator mapper);
/**
* Note: copied from StreamEx: StreamEx
*
*
* Returns a stream consisting of results of applying the given function to
* the ranges created from the source elements.
* This is a quasi-intermediate
* partial reduction operation.
*
* @param
* @param sameRange a non-interfering, stateless predicate to apply to
* the leftmost and next elements which returns {@code true} for elements
* which belong to the same range.
* @param mapper a non-interfering, stateless function to apply to the
* range borders and produce the resulting element. If the value was
* not merged to the interval, then mapper will receive the same
* value twice, otherwise it will receive the leftmost and the
* rightmost values which were merged to the range.
* @return
* @see Stream#rangeMap(BiPredicate, BiFunction)
*/
@SequentialOnly
@IntermediateOp
public abstract Stream rangeMapToObj(final LongBiPredicate sameRange, final LongBiFunction mapper);
/**
* Merges a series of adjacent elements in the stream which satisfy the given predicate into a List.
* The predicate takes two parameters: the previous element and the current element in the stream.
* If the predicate returns {@code true}, the current element and its previous element are considered as a series of adjacent elements.
* These elements are then collapsed into a List.
*
* This is an intermediate operation, meaning it's always lazy. It doesn't start processing the data until a terminal operation is invoked on the stream pipeline.
* It's also a stateful operation since it needs to remember the previous element when processing the current element.
*
* This operation is not parallelizable and requires the stream to be ordered.
*
* @param collapsible a BiPredicate that takes two parameters: the previous element and the current element in the stream.
* @return a new Stream where each element is a List of adjacent elements which satisfy the given predicate.
* @see Stream#collapse(BiPredicate)
*/
@SequentialOnly
@IntermediateOp
public abstract Stream collapse(final LongBiPredicate collapsible);
/**
* Merges a series of adjacent elements in the stream which satisfy the given predicate using the merger function and returns a new stream.
* The predicate takes two parameters: the previous element and the current element in the stream.
* If the predicate returns {@code true}, the current element and its previous element are considered as a series of adjacent elements.
* These elements are then merged using the provided BiFunction.
*
* This is an intermediate operation, meaning it's always lazy. It doesn't start processing the data until a terminal operation is invoked on the stream pipeline.
* It's also a stateful operation since it needs to remember the previous element when processing the current element.
*
* This operation is not parallelizable and requires the stream to be ordered.
*
* @param collapsible a BiPredicate that takes two parameters: the previous element and the current element in the stream.
* @param mergeFunction a BiFunction that takes two parameters: the result of the previous merge operation (or the first element if no merge has been performed yet) and the current element, and returns the result of the merge operation.
* @return a new Stream where each element is the result of merging adjacent elements which satisfy the given predicate.
* @see Stream#collapse(BiPredicate, BiFunction)
*/
@SequentialOnly
@IntermediateOp
public abstract LongStream collapse(final LongBiPredicate collapsible, final LongBinaryOperator mergeFunction);
/**
* Merges a series of adjacent elements in the stream which satisfy the given predicate into a single element and returns a new stream.
* The predicate takes three parameters: the first element of the series, the previous element and the current element in the stream.
* If the predicate returns {@code true}, the current element, its previous element and the first element of the series are considered as a series of adjacent elements.
* These elements are then collapsed into a single element using the provided merge function.
*
* This is an intermediate operation, meaning it's always lazy. It doesn't start processing the data until a terminal operation is invoked on the stream pipeline.
* It's also a stateful operation since it needs to remember the first and previous elements when processing the current element.
*
* This operation is not parallelizable and requires the stream to be ordered.
*
* @param collapsible a TriPredicate that takes three parameters: the first element of the series, the previous element and the current element in the stream.
* @param mergeFunction a BiFunction that takes two parameters: the current element and its previous element. It returns a single element that represents the collapsed elements.
* @return a new Stream where each element is the result of collapsing adjacent elements which satisfy the given predicate.
* @see Stream#collapse(com.landawn.abacus.util.function.TriPredicate, BiFunction)
*/
@SequentialOnly
@IntermediateOp
public abstract LongStream collapse(final LongTriPredicate collapsible, final LongBinaryOperator mergeFunction);
/**
* Performs a scan (also known as prefix sum, cumulative sum, running total, or integral) operation on the elements of the stream.
* The scan operation takes a binary operator (the accumulator) and applies it cumulatively on the stream elements,
* successively combining each element in order from the start to produce a stream of accumulated results.
*
* For example, given a stream of numbers [1, 2, 3, 4], and an accumulator that performs addition,
* the output would be a stream of numbers [1, 3, 6, 10].
*
* This is an intermediate operation.
* This operation is sequential only, even when called on a parallel stream.
*
* @param accumulator a {@code LongBinaryOperator} that takes two parameters: the current accumulated value and the current stream element, and returns a new accumulated value.
* @return a new {@code LongStream} consisting of the results of the scan operation on the elements of the original stream.
* @see Stream#scan(BiFunction)
*/
@SequentialOnly
@IntermediateOp
public abstract LongStream scan(final LongBinaryOperator accumulator);
/**
* Performs a scan (also known as prefix sum, cumulative sum, running total, or integral) operation on the elements of the stream.
* The scan operation takes an initial value and a binary operator (the accumulator) and applies it cumulatively on the stream elements,
* successively combining each element in order from the start to produce a stream of accumulated results.
*
* For example, given a stream of numbers [1, 2, 3, 4], an initial value of 10, and an accumulator that performs addition,
* the output would be a stream of numbers [11, 13, 16, 20].
* This is an intermediate operation.
* This operation is sequential only, even when called on a parallel stream.
*
* @param init the initial value. It's only used once by the accumulator to calculate the first element in the returned stream.
* It will be ignored if this stream is empty and won't be the first element of the returned stream.
* @param accumulator a {@code LongBinaryOperator} that takes two parameters: the current accumulated value and the current stream element, and returns a new accumulated value.
* @return a new {@code LongStream} consisting of the results of the scan operation on the elements of the original stream.
* @see Stream#scan(Object, BiFunction)
*/
@SequentialOnly
@IntermediateOp
public abstract LongStream scan(final long init, final LongBinaryOperator accumulator);
/**
* Performs a scan (also known as prefix sum, cumulative sum, running total, or integral) operation on the elements of the stream.
* The scan operation takes an initial value and a binary operator (the accumulator) and applies it cumulatively on the stream elements,
* successively combining each element in order from the start to produce a stream of accumulated results.
*
* This is an intermediate operation.
* This operation is sequential only, even when called on a parallel stream.
*
* @param init the initial value. It's only used once by the accumulator to calculate the first element in the returned stream.
* @param initIncluded a boolean value that determines if the initial value should be included as the first element in the returned stream.
* @param accumulator a {@code LongBinaryOperator} that takes two parameters: the current accumulated value and the current stream element, and returns a new accumulated value.
* @return a new {@code LongStream} consisting of the results of the scan operation on the elements of the original stream.
* @see Stream#scan(Object, boolean, BiFunction)
*/
@SequentialOnly
@IntermediateOp
public abstract LongStream scan(final long init, final boolean initIncluded, final LongBinaryOperator accumulator);
/**
*
* @param a
* @return
*/
@SequentialOnly
@IntermediateOp
public abstract LongStream prepend(final long... a);
/**
*
* @param a
* @return
*/
@SequentialOnly
@IntermediateOp
public abstract LongStream append(final long... a);
/**
*
* @param a
* @return
*/
@SequentialOnly
@IntermediateOp
public abstract LongStream appendIfEmpty(final long... a);
/**
*
* This method only runs sequentially, even in parallel stream.
*
* @param n
* @return
*/
@SequentialOnly
@IntermediateOp
public abstract LongStream top(int n);
/**
*
* This method only runs sequentially, even in parallel stream.
*
* @param n
* @param comparator
* @return
*/
@SequentialOnly
@IntermediateOp
public abstract LongStream top(final int n, Comparator comparator);
@SequentialOnly
@TerminalOp
public abstract LongList toLongList();
/**
*
* @param
* @param
* @param
* @param
* @param keyMapper
* @param valueMapper
* @return
* @throws E
* @throws E2
* @see Collectors#toMap(Function, Function)
*/
@ParallelSupported
@TerminalOp
public abstract Map toMap(Throwables.LongFunction keyMapper,
Throwables.LongFunction valueMapper) throws E, E2;
/**
*
* @param
* @param
* @param
* @param
* @param
* @param keyMapper
* @param valueMapper
* @param mapFactory
* @return
* @throws E
* @throws E2
* @see Collectors#toMap(Function, Function, Supplier)
*/
@ParallelSupported
@TerminalOp
public abstract , E extends Exception, E2 extends Exception> M toMap(Throwables.LongFunction keyMapper,
Throwables.LongFunction valueMapper, Supplier mapFactory) throws E, E2;
/**
*
* @param
* @param
* @param
* @param
* @param keyMapper
* @param valueMapper
* @param mergeFunction
* @return
* @throws E
* @throws E2
* @see Collectors#toMap(Function, Function, BinaryOperator)
*/
@ParallelSupported
@TerminalOp
public abstract Map toMap(Throwables.LongFunction keyMapper,
Throwables.LongFunction valueMapper, BinaryOperator mergeFunction) throws E, E2;
/**
*
* @param
* @param
* @param
* @param
* @param
* @param keyMapper
* @param valueMapper
* @param mergeFunction
* @param mapFactory
* @return
* @throws E
* @throws E2
* @see Collectors#toMap(Function, Function, BinaryOperator, Supplier)
*/
@ParallelSupported
@TerminalOp
public abstract , E extends Exception, E2 extends Exception> M toMap(Throwables.LongFunction keyMapper,
Throwables.LongFunction valueMapper, BinaryOperator mergeFunction, Supplier mapFactory) throws E, E2;
/**
*
* @param
* @param
* @param
* @param keyMapper
* @param downstream
* @return
* @throws E
* @see Collectors#groupingBy(Function, Collector)
*/
@ParallelSupported
@TerminalOp
public abstract Map groupTo(Throwables.LongFunction keyMapper,
final Collector downstream) throws E;
/**
*
* @param
* @param
* @param
* @param
* @param keyMapper
* @param downstream
* @param mapFactory
* @return
* @throws E
* @see Collectors#groupingBy(Function, Collector, Supplier)
*/
@ParallelSupported
@TerminalOp
public abstract , E extends Exception> M groupTo(Throwables.LongFunction keyMapper,
final Collector downstream, final Supplier mapFactory) throws E;
/**
* Performs a reduction on the elements of this stream, using the provided accumulator function, and returns the reduced value.
* The accumulator function takes two parameters: the current reduced value (or the initial value for the first element), and the current stream element.
*
* @param identity the initial value of the reduction operation
* @param op the function for combining the current reduced value and the current stream element
* @return the result of the reduction
* @see Stream#reduce(Object, BinaryOperator)
*/
@ParallelSupported
@TerminalOp
public abstract long reduce(long identity, LongBinaryOperator op);
/**
* Performs a reduction on the elements of this stream, using the provided accumulator function, and returns the reduced value.
* The accumulator function takes two parameters: the current reduced value and the current stream element.
*
* @param op the function for combining the current reduced value and the current stream element
* @return an OptionalLong describing the result of the reduction. If the stream is empty, an empty OptionalLong is returned.
* @see Stream#reduce(BinaryOperator)
*/
@ParallelSupported
@TerminalOp
public abstract OptionalLong reduce(LongBinaryOperator op);
/**
* Performs a mutable reduction operation on the elements of this stream using a Collector.
*
* @param The type of the result
* @param supplier a function that creates a new result container. For a parallel execution, this function may be called multiple times and must return a fresh value each time.
* @param accumulator an associative, non-interfering, stateless function for incorporating an additional element into a result
* @param combiner an associative, non-interfering, stateless function for combining two values, which must be compatible with the accumulator function.
* It's unnecessary to specify {@code combiner} if {@code R} is a {@code Map/Collection/StringBuilder/Multiset/LongMultiset/Multimap/BooleanList/IntList/.../DoubleList}.
* @return the result of the reduction
* @see Stream#collect(Supplier, BiConsumer, BiConsumer)
* @see BiConsumers#ofAddAll()
* @see BiConsumers#ofPutAll()
*/
@ParallelSupported
@TerminalOp
public abstract R collect(Supplier supplier, ObjLongConsumer accumulator, BiConsumer combiner);
/**
* Performs a mutable reduction operation on the elements of this stream using a Collector.
*
*
* Only call this method when the returned type {@code R} is one types: {@code Collection/Map/StringBuilder/Multiset/LongMultiset/Multimap/BooleanList/IntList/.../DoubleList}.
* Otherwise, please call {@link #collect(Supplier, ObjLongConsumer, BiConsumer)}.
*
* @param The type of the result. It must be {@code Collection/Map/StringBuilder/Multiset/LongMultiset/Multimap/BooleanList/IntList/.../DoubleList}.
* @param supplier A function that creates a new result container. For a parallel execution, this function may be called multiple times and must return a fresh value each time.
* @param accumulator An associative, non-interfering, stateless function for incorporating an additional element into a result.
* @throws IllegalArgumentException if the returned type {@code R} is not one of the types: {@code Collection/Map/StringBuilder/Multiset/LongMultiset/Multimap/BooleanList/IntList/.../DoubleList}.
* @return the result of the reduction
* @see #collect(Supplier, ObjLongConsumer, BiConsumer)
* @see Stream#collect(Supplier, BiConsumer)
* @see Stream#collect(Supplier, BiConsumer, BiConsumer)
*/
@ParallelSupported
@TerminalOp
public abstract R collect(Supplier supplier, ObjLongConsumer accumulator);
/**
*
* @param action
*/
@ParallelSupported
@TerminalOp
public void foreach(final LongConsumer action) { // NOSONAR
forEach(action::accept);
}
/**
*
* @param
* @param action
* @throws E
*/
@ParallelSupported
@TerminalOp
public abstract void forEach(final Throwables.LongConsumer action) throws E; //NOSONAR
/**
*
* @param
* @param action
* @throws E
*/
@ParallelSupported
@TerminalOp
public abstract void forEachIndexed(Throwables.IntLongConsumer action) throws E;
/**
*
* @param
* @param predicate
* @return
* @throws E
*/
@ParallelSupported
@TerminalOp
public abstract boolean anyMatch(final Throwables.LongPredicate predicate) throws E;
/**
*
* @param
* @param predicate
* @return
* @throws E
*/
@ParallelSupported
@TerminalOp
public abstract boolean allMatch(final Throwables.LongPredicate predicate) throws E;
/**
*
* @param
* @param predicate
* @return
* @throws E
*/
@ParallelSupported
@TerminalOp
public abstract boolean noneMatch(final Throwables.LongPredicate predicate) throws E;
/**
*
* @param
* @param predicate
* @return
* @throws E
*/
@ParallelSupported
@TerminalOp
public abstract OptionalLong findFirst(final Throwables.LongPredicate predicate) throws E;
/**
*
* @param
* @param predicate
* @return
* @throws E
*/
@ParallelSupported
@TerminalOp
public abstract OptionalLong findAny(final Throwables.LongPredicate predicate) throws E;
/**
* Consider using: {@code stream.reversed().findFirst(predicate)} for better performance if possible.
*
* @param
* @param predicate
* @return
* @throws E
*/
@Beta
@ParallelSupported
@TerminalOp
public abstract OptionalLong findLast(final Throwables.LongPredicate predicate) throws E;
// /**
// * Returns the first element matched by {@code predicateForFirst} if found or the first element if this stream is not empty.
// * Otherwise, an empty {@code OptionalLong} will be returned.
// *
// * @param
// * @param predicateForFirst
// * @return
// * @throws E
// */
// @ParallelSupported
// @TerminalOp
// public abstract OptionalLong findFirstOrElseAny(Throwables.LongPredicate predicateForFirst) throws E;
//
// /**
// * Returns the first element matched by {@code predicateForFirst} if found or the last element if this stream is not empty.
// * Otherwise, an empty {@code OptionalLong} will be returned.
// *
// * @param
// * @param predicateForFirst
// * @return
// * @throws E
// */
// @ParallelSupported
// @TerminalOp
// public abstract OptionalLong findFirstOrElseLast(Throwables.LongPredicate predicateForFirst) throws E;
@SequentialOnly
@TerminalOp
public abstract OptionalLong min();
@SequentialOnly
@TerminalOp
public abstract OptionalLong max();
/**
* Returns the k-th largest element in the stream.
* If the stream is empty or the count of elements is less than k, an empty OptionalLong is returned.
*
* @param k the position (1-based) of the largest element to retrieve
* @return an OptionalLong containing the k-th largest element, or an empty OptionalLong if the stream is empty or the count of elements is less than k
*/
@SequentialOnly
@TerminalOp
public abstract OptionalLong kthLargest(int k);
@SequentialOnly
@TerminalOp
public abstract long sum();
@SequentialOnly
@TerminalOp
public abstract OptionalDouble average();
@SequentialOnly
@TerminalOp
public abstract LongSummaryStatistics summarize();
@SequentialOnly
@TerminalOp
public abstract Pair>> summarizeAndPercentiles();
// /**
// *
// * @param b
// * @param nextSelector a function to determine which element should be selected as the next element.
// * The first parameter is selected if {@code MergeResult.TAKE_FIRST} is returned, otherwise the second parameter is selected.
// * @return
// * @deprecated replaced by {@code mergeWith(LongStream, LongBiFunction)}
// * @see #mergeWith(LongStream, LongBiFunction)
// */
// @SequentialOnly
// @IntermediateOp
// @Deprecated
// public LongStream merge(final LongStream b, final LongBiFunction nextSelector) {
// return mergeWith(b, nextSelector);
// }
/**
*
* @param b
* @param nextSelector a function to determine which element should be selected as the next element.
* The first parameter is selected if {@code MergeResult.TAKE_FIRST} is returned, otherwise the second parameter is selected.
* @return
*/
@SequentialOnly
@IntermediateOp
public abstract LongStream mergeWith(final LongStream b, final LongBiFunction nextSelector);
/**
*
* @param b
* @param zipFunction
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract LongStream zipWith(LongStream b, LongBinaryOperator zipFunction);
/**
*
* @param b
* @param c
* @param zipFunction
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract LongStream zipWith(LongStream b, LongStream c, LongTernaryOperator zipFunction);
/**
*
* @param b
* @param valueForNoneA
* @param valueForNoneB
* @param zipFunction
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract LongStream zipWith(LongStream b, long valueForNoneA, long valueForNoneB, LongBinaryOperator zipFunction);
/**
*
* @param b
* @param c
* @param valueForNoneA
* @param valueForNoneB
* @param valueForNoneC
* @param zipFunction
* @return
*/
@ParallelSupported
@IntermediateOp
public abstract LongStream zipWith(LongStream b, LongStream c, long valueForNoneA, long valueForNoneB, long valueForNoneC, LongTernaryOperator zipFunction);
/**
* Converts this LongStream to a FloatStream.
*
* @return a FloatStream representation of this LongStream.
* @deprecated uncertain.
*/
@SequentialOnly
@IntermediateOp
@Deprecated
public abstract FloatStream asFloatStream();
@SequentialOnly
@IntermediateOp
public abstract DoubleStream asDoubleStream();
// No performance improvement.
// /**
// * Temporarily switch the stream to Jdk parallel stream for operation {@code ops} and then switch back to sequence stream.
// *
// * {@code stream.(switchToJdkStream).parallel().ops(map/filter/...).(switchBack).sequence()}
// *
// * @param
// * @param op
// * @return
// */
// @Beta
// @IntermediateOp
// public LongStream sjps(Function op) {
// if (this.isParallel()) {
// return of(op.apply(this.toJdkStream())).sequential();
// } else {
// return of(op.apply(this.toJdkStream().parallel()));
// }
// }
@SequentialOnly
@IntermediateOp
public abstract Stream boxed();
@SequentialOnly
@IntermediateOp
public abstract java.util.stream.LongStream toJdkStream();
/**
*
* @param transfer
* @return
*/
@Beta
@SequentialOnly
@IntermediateOp
public LongStream transformB(final Function transfer) {
return transformB(transfer, false);
}
/**
*
* @param transfer
* @param deferred
* @return
* @throws IllegalArgumentException
*/
@Beta
@SequentialOnly
@IntermediateOp
public LongStream transformB(final Function transfer, final boolean deferred)
throws IllegalArgumentException {
assertNotClosed();
checkArgNotNull(transfer, cs.transfer);
if (deferred) {
final Supplier delayInitializer = () -> LongStream.from(transfer.apply(toJdkStream()));
return LongStream.defer(delayInitializer);
} else {
return LongStream.from(transfer.apply(toJdkStream()));
}
}
abstract LongIteratorEx iteratorEx();
// private static final LongStream EMPTY_STREAM = new ArrayLongStream(N.EMPTY_LONG_ARRAY, true, null);
/**
* Returns an empty LongStream.
*
* @return an empty LongStream
*/
public static LongStream empty() {
return new ArrayLongStream(N.EMPTY_LONG_ARRAY, true, null);
}
/**
* Creates a new LongStream that is supplied by the given supplier.
* The supplier is only invoked when the stream is actually used.
* This allows for lazy evaluation of the stream.
*
* @implNote it's equivalent to {@code Stream.just(supplier).flatMapToLong(it -> it.get())}.
*
* @param supplier the supplier that provides the LongStream
* @return a new LongStream supplied by the given supplier
* @throws IllegalArgumentException if the supplier is null
* @see Stream#defer(Supplier)
*/
public static LongStream defer(final Supplier supplier) throws IllegalArgumentException {
N.checkArgNotNull(supplier, cs.supplier);
//noinspection resource
return Stream.just(supplier).flatMapToLong(Supplier::get);
}
/**
*
* @param stream
* @return
*/
public static LongStream from(final java.util.stream.LongStream stream) {
if (stream == null) {
return empty();
}
return of(new LongIteratorEx() {
private PrimitiveIterator.OfLong iter = null;
@Override
public boolean hasNext() {
if (iter == null) {
iter = stream.iterator();
}
return iter.hasNext();
}
@Override
public long nextLong() {
if (iter == null) {
iter = stream.iterator();
}
return iter.nextLong();
}
@Override
public long count() {
return iter == null ? stream.count() : super.count();
}
@Override
public void advance(final long n) {
if (iter == null) {
iter = stream.skip(n).iterator();
} else {
super.advance(n);
}
}
@Override
public long[] toArray() {
return iter == null ? stream.toArray() : super.toArray();
}
}).transform(s -> stream.isParallel() ? s.parallel() : s.sequential()).onClose(stream::close);
}
/**
*
* @param e
* @return
*/
public static LongStream ofNullable(final Long e) {
return e == null ? empty() : of(e);
}
/**
*
* @param a
* @return
*/
public static LongStream of(final long... a) {
return N.isEmpty(a) ? empty() : new ArrayLongStream(a);
}
/**
*
* @param a
* @param startIndex
* @param endIndex
* @return
*/
public static LongStream of(final long[] a, final int startIndex, final int endIndex) {
return N.isEmpty(a) && (startIndex == 0 && endIndex == 0) ? empty() : new ArrayLongStream(a, startIndex, endIndex);
}
/**
*
* @param a
* @return
*/
public static LongStream of(final Long[] a) {
//noinspection resource
return Stream.of(a).mapToLong(FL.unbox());
}
/**
*
* @param a
* @param startIndex
* @param endIndex
* @return
*/
public static LongStream of(final Long[] a, final int startIndex, final int endIndex) {
//noinspection resource
return Stream.of(a, startIndex, endIndex).mapToLong(FL.unbox());
}
/**
*
* @param c
* @return
*/
public static LongStream of(final Collection c) {
//noinspection resource
return Stream.of(c).mapToLong(FL.unbox());
}
/**
*
* @param iterator
* @return
*/
public static LongStream of(final LongIterator iterator) {
return iterator == null ? empty() : new IteratorLongStream(iterator);
}
/**
*
* @param stream
* @return
* @deprecated Use {@link #from(java.util.stream.LongStream)} instead
*/
// Should the name be from?
@Deprecated
public static LongStream of(final java.util.stream.LongStream stream) {
return from(stream);
}
/**
*
* @param buf
* @return
*/
public static LongStream of(final LongBuffer buf) {
if (buf == null) {
return empty();
}
//noinspection resource
return IntStream.range(buf.position(), buf.limit()).mapToLong(buf::get);
}
/**
*
* @param op
* @return
*/
public static LongStream of(final OptionalLong op) {
return op == null || op.isEmpty() ? LongStream.empty() : LongStream.of(op.get());
}
/**
*
* @param op
* @return
*/
public static LongStream of(final java.util.OptionalLong op) {
return op == null || op.isEmpty() ? LongStream.empty() : LongStream.of(op.getAsLong());
}
private static final Function flatMapper = LongStream::of;
private static final Function flattMapper = LongStream::flatten;
/**
*
* @param a
* @return
*/
public static LongStream flatten(final long[][] a) {
//noinspection resource
return N.isEmpty(a) ? empty() : Stream.of(a).flatMapToLong(flatMapper);
}
/**
*
* @param a
* @param vertically
* @return
*/
public static LongStream flatten(final long[][] a, final boolean vertically) {
if (N.isEmpty(a)) {
return empty();
} else if (a.length == 1) {
return of(a[0]);
} else if (!vertically) {
//noinspection resource
return Stream.of(a).flatMapToLong(flatMapper);
}
long n = 0;
for (final long[] e : a) {
n += N.len(e);
}
if (n == 0) {
return empty();
}
final int rows = N.len(a);
final long count = n;
final LongIterator iter = new LongIteratorEx() {
private int rowNum = 0;
private int colNum = 0;
private long cnt = 0;
@Override
public boolean hasNext() {
return cnt < count;
}
@Override
public long nextLong() {
if (cnt++ >= count) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
if (rowNum == rows) {
rowNum = 0;
colNum++;
}
while (a[rowNum] == null || colNum >= a[rowNum].length) {
if (rowNum < rows - 1) {
rowNum++;
} else {
rowNum = 0;
colNum++;
}
}
return a[rowNum++][colNum];
}
};
return of(iter);
}
/**
*
* @param a
* @param valueForAlignment element to append, so there is the same size of elements in all rows/columns
* @param vertically
* @return
*/
public static LongStream flatten(final long[][] a, final long valueForAlignment, final boolean vertically) {
if (N.isEmpty(a)) {
return empty();
} else if (a.length == 1) {
return of(a[0]);
}
long n = 0;
int maxLen = 0;
for (final long[] e : a) {
n += N.len(e);
maxLen = N.max(maxLen, N.len(e));
}
if (n == 0) {
return empty();
}
final int rows = N.len(a);
final int cols = maxLen;
final long count = ((long) rows) * cols;
LongIterator iter = null;
if (vertically) {
iter = new LongIteratorEx() {
private int rowNum = 0;
private int colNum = 0;
private long cnt = 0;
@Override
public boolean hasNext() {
return cnt < count;
}
@Override
public long nextLong() {
if (cnt++ >= count) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
if (rowNum == rows) {
rowNum = 0;
colNum++;
}
if (a[rowNum] == null || colNum >= a[rowNum].length) {
rowNum++;
return valueForAlignment;
} else {
return a[rowNum++][colNum];
}
}
};
} else {
iter = new LongIteratorEx() {
private int rowNum = 0;
private int colNum = 0;
private long cnt = 0;
@Override
public boolean hasNext() {
return cnt < count;
}
@Override
public long nextLong() {
if (cnt++ >= count) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
if (colNum >= cols) {
colNum = 0;
rowNum++;
}
if (a[rowNum] == null || colNum >= a[rowNum].length) {
colNum++;
return valueForAlignment;
} else {
return a[rowNum][colNum++];
}
}
};
}
return of(iter);
}
/**
*
* @param a
* @return
*/
public static LongStream flatten(final long[][][] a) {
//noinspection resource
return N.isEmpty(a) ? empty() : Stream.of(a).flatMapToLong(flattMapper);
}
/**
*
* @param startInclusive
* @param endExclusive
* @return
*/
public static LongStream range(final long startInclusive, final long endExclusive) {
if (startInclusive >= endExclusive) {
return empty();
} else if (endExclusive - startInclusive < 0) {
final long m = BigInteger.valueOf(endExclusive).subtract(BigInteger.valueOf(startInclusive)).divide(BigInteger.valueOf(3)).longValue();
return concat(range(startInclusive, startInclusive + m), range(startInclusive + m, (startInclusive + m) + m),
range((startInclusive + m) + m, endExclusive));
}
return new IteratorLongStream(new LongIteratorEx() {
private long next = startInclusive;
private long cnt = endExclusive - startInclusive;
@Override
public boolean hasNext() {
return cnt > 0;
}
@Override
public long nextLong() {
if (cnt-- <= 0) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
return next++;
}
@Override
public void advance(final long n) {
cnt = n >= cnt ? 0 : cnt - n;
next += n;
}
@Override
public long count() {
return cnt;
}
@Override
public long[] toArray() {
final long[] result = new long[(int) cnt];
for (int i = 0; i < cnt; i++) {
result[i] = next++;
}
cnt = 0;
return result;
}
});
}
/**
*
* @param startInclusive
* @param endExclusive
* @param by
* @return
*/
public static LongStream range(final long startInclusive, final long endExclusive, final long by) {
if (by == 0) {
throw new IllegalArgumentException("'by' can't be zero");
}
if (endExclusive == startInclusive || endExclusive > startInclusive != by > 0) {
return empty();
}
if ((by > 0 && endExclusive - startInclusive < 0) || (by < 0 && startInclusive - endExclusive < 0)) {
long m = BigInteger.valueOf(endExclusive).subtract(BigInteger.valueOf(startInclusive)).divide(BigInteger.valueOf(3)).longValue();
if ((by > 0 && by > m) || (by < 0 && by < m)) {
return concat(range(startInclusive, startInclusive + by), range(startInclusive + by, endExclusive));
} else {
m = m > 0 ? m - m % by : m + m % by;
return concat(range(startInclusive, startInclusive + m, by), range(startInclusive + m, (startInclusive + m) + m, by),
range((startInclusive + m) + m, endExclusive, by));
}
}
return new IteratorLongStream(new LongIteratorEx() {
private long next = startInclusive;
private long cnt = (endExclusive - startInclusive) / by + ((endExclusive - startInclusive) % by == 0 ? 0 : 1);
@Override
public boolean hasNext() {
return cnt > 0;
}
@Override
public long nextLong() {
if (cnt-- <= 0) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
final long result = next;
next += by;
return result;
}
@Override
public void advance(final long n) {
cnt = n >= cnt ? 0 : cnt - n;
next += n * by;
}
@Override
public long count() {
return cnt;
}
@Override
public long[] toArray() {
final long[] result = new long[(int) cnt];
for (int i = 0; i < cnt; i++, next += by) {
result[i] = next;
}
cnt = 0;
return result;
}
});
}
/**
*
* @param startInclusive
* @param endInclusive
* @return
*/
public static LongStream rangeClosed(final long startInclusive, final long endInclusive) {
if (startInclusive > endInclusive) {
return empty();
} else if (startInclusive == endInclusive) {
return of(startInclusive);
} else if (endInclusive - startInclusive + 1 <= 0) {
final long m = BigInteger.valueOf(endInclusive).subtract(BigInteger.valueOf(startInclusive)).divide(BigInteger.valueOf(3)).longValue();
return concat(range(startInclusive, startInclusive + m), range(startInclusive + m, (startInclusive + m) + m),
rangeClosed((startInclusive + m) + m, endInclusive));
}
return new IteratorLongStream(new LongIteratorEx() {
private long next = startInclusive;
private long cnt = endInclusive - startInclusive + 1;
@Override
public boolean hasNext() {
return cnt > 0;
}
@Override
public long nextLong() {
if (cnt-- <= 0) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
return next++;
}
@Override
public void advance(final long n) {
cnt = n >= cnt ? 0 : cnt - n;
next += n;
}
@Override
public long count() {
return cnt;
}
@Override
public long[] toArray() {
final long[] result = new long[(int) cnt];
for (int i = 0; i < cnt; i++) {
result[i] = next++;
}
cnt = 0;
return result;
}
});
}
/**
*
* @param startInclusive
* @param endInclusive
* @param by
* @return
*/
public static LongStream rangeClosed(final long startInclusive, final long endInclusive, final long by) {
if (by == 0) {
throw new IllegalArgumentException("'by' can't be zero");
}
if (endInclusive == startInclusive) {
return of(startInclusive);
} else if (endInclusive > startInclusive != by > 0) {
return empty();
}
if ((by > 0 && endInclusive - startInclusive < 0) || (by < 0 && startInclusive - endInclusive < 0) || ((endInclusive - startInclusive) / by + 1 <= 0)) {
long m = BigInteger.valueOf(endInclusive).subtract(BigInteger.valueOf(startInclusive)).divide(BigInteger.valueOf(3)).longValue();
if ((by > 0 && by > m) || (by < 0 && by < m)) {
return concat(range(startInclusive, startInclusive + by), rangeClosed(startInclusive + by, endInclusive));
} else {
m = m > 0 ? m - m % by : m + m % by;
return concat(range(startInclusive, startInclusive + m, by), range(startInclusive + m, (startInclusive + m) + m, by),
rangeClosed((startInclusive + m) + m, endInclusive, by));
}
}
return new IteratorLongStream(new LongIteratorEx() {
private long next = startInclusive;
private long cnt = (endInclusive - startInclusive) / by + 1;
@Override
public boolean hasNext() {
return cnt > 0;
}
@Override
public long nextLong() {
if (cnt-- <= 0) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
final long result = next;
next += by;
return result;
}
@Override
public void advance(final long n) {
cnt = n >= cnt ? 0 : cnt - n;
next += n * by;
}
@Override
public long count() {
return cnt;
}
@Override
public long[] toArray() {
final long[] result = new long[(int) cnt];
for (int i = 0; i < cnt; i++, next += by) {
result[i] = next;
}
cnt = 0;
return result;
}
});
}
/**
*
* @param element
* @param n
* @return
* @throws IllegalArgumentException
*/
public static LongStream repeat(final long element, final long n) throws IllegalArgumentException {
N.checkArgNotNegative(n, cs.n);
if (n == 0) {
return empty();
} else if (n < 10) {
return of(Array.repeat(element, (int) n));
}
return new IteratorLongStream(new LongIteratorEx() {
private long cnt = n;
@Override
public boolean hasNext() {
return cnt > 0;
}
@Override
public long nextLong() {
if (cnt-- <= 0) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
return element;
}
@Override
public void advance(final long n) {
cnt = n >= cnt ? 0 : cnt - (int) n;
}
@Override
public long count() {
return cnt;
}
@Override
public long[] toArray() {
final long[] result = new long[(int) cnt];
for (int i = 0; i < cnt; i++) {
result[i] = element;
}
cnt = 0;
return result;
}
});
}
public static LongStream random() {
return generate(RAND::nextLong);
}
/**
* Generates a LongStream that emits elements([0, 1, 2, 3...]) at a fixed interval.
*
* @param intervalInMillis the interval between elements in milliseconds
* @return a LongStream that emits elements at the specified interval
*/
@Beta
public static LongStream interval(final long intervalInMillis) {
return interval(0, intervalInMillis);
}
/**
* Generates a LongStream that emits elements([0, 1, 2, 3...]) at a fixed interval after an initial delay.
*
* @param delayInMillis the initial delay before the first element is emitted, in milliseconds
* @param intervalInMillis the interval between subsequent elements, in milliseconds
* @return a LongStream that emits elements at the specified interval after the initial delay
*/
@Beta
public static LongStream interval(final long delayInMillis, final long intervalInMillis) {
return interval(delayInMillis, intervalInMillis, TimeUnit.MILLISECONDS);
}
/**
* Generates a LongStream that emits elements([0, 1, 2, 3...]) at a fixed interval after an initial delay.
*
* @param delay the initial delay before the first element is emitted
* @param interval the interval between subsequent elements
* @param unit the time unit of the delay and interval
* @return a LongStream that emits elements at the specified interval after the initial delay
*/
@Beta
public static LongStream interval(final long delay, final long interval, final TimeUnit unit) {
return of(new LongIteratorEx() {
private final long intervalInMillis = unit.toMillis(interval);
private long nextTime = System.currentTimeMillis() + unit.toMillis(delay);
private long val = 0;
@Override
public boolean hasNext() {
return true;
}
@Override
public long nextLong() {
final long now = System.currentTimeMillis();
if (now < nextTime) {
N.sleepUninterruptibly(nextTime - now);
}
nextTime += intervalInMillis;
return val++;
}
});
}
/**
* Creates a stream that iterates using the given hasNext and next suppliers.
*
* @param hasNext a BooleanSupplier that returns {@code true} if the iteration should continue
* @param next a LongSupplier that provides the next long in the iteration
* @return a LongStream of elements generated by the iteration
* @throws IllegalArgumentException if hasNext or next is null
* @see Stream#iterate(BooleanSupplier, Supplier)
*/
public static LongStream iterate(final BooleanSupplier hasNext, final LongSupplier next) throws IllegalArgumentException {
N.checkArgNotNull(hasNext);
N.checkArgNotNull(next);
return new IteratorLongStream(new LongIteratorEx() {
private boolean hasNextVal = false;
@Override
public boolean hasNext() {
if (!hasNextVal) {
hasNextVal = hasNext.getAsBoolean();
}
return hasNextVal;
}
@Override
public long nextLong() {
if (!hasNextVal && !hasNext()) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
hasNextVal = false;
return next.getAsLong();
}
});
}
/**
* Creates a stream that iterates from an initial value, applying a function to generate subsequent values,
* and continues as long as a predicate is satisfied.
*
* @param init the initial value
* @param hasNext a BooleanSupplier that returns {@code true} if the iteration should continue
* @param f a function to apply to the previous element to generate the next element
* @return a LongStream of elements generated by the iteration
* @throws IllegalArgumentException if hasNext or f is null
* @see Stream#iterate(Object, BooleanSupplier, java.util.function.UnaryOperator)
*/
public static LongStream iterate(final long init, final BooleanSupplier hasNext, final LongUnaryOperator f) throws IllegalArgumentException {
N.checkArgNotNull(hasNext);
N.checkArgNotNull(f);
return new IteratorLongStream(new LongIteratorEx() {
private long cur = 0;
private boolean isFirst = true;
private boolean hasNextVal = false;
@Override
public boolean hasNext() {
if (!hasNextVal) {
hasNextVal = hasNext.getAsBoolean();
}
return hasNextVal;
}
@Override
public long nextLong() {
if (!hasNextVal && !hasNext()) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
hasNextVal = false;
if (isFirst) {
isFirst = false;
cur = init;
} else {
cur = f.applyAsLong(cur);
}
return cur;
}
});
}
/**
* Creates a stream that iterates from an initial value, applying a function to generate subsequent values,
* and continues as long as a predicate is satisfied.
*
* @param init the initial value
* @param hasNext determinate if the returned stream has next by hasNext.test(init) for the first time and hasNext.test(f.apply(previous)) for remaining.
* @param f a function to apply to the previous element to generate the next element
* @return a LongStream of elements generated by the iteration
* @throws IllegalArgumentException if hasNext or f is null
* @see Stream#iterate(Object, java.util.function.Predicate, java.util.function.UnaryOperator)
*/
public static LongStream iterate(final long init, final LongPredicate hasNext, final LongUnaryOperator f) throws IllegalArgumentException {
N.checkArgNotNull(hasNext);
N.checkArgNotNull(f);
return new IteratorLongStream(new LongIteratorEx() {
private long cur = 0;
private boolean isFirst = true;
private boolean hasMore = true;
private boolean hasNextVal = false;
@Override
public boolean hasNext() {
if (!hasNextVal && hasMore) {
if (isFirst) {
isFirst = false;
hasNextVal = hasNext.test(cur = init);
} else {
hasNextVal = hasNext.test(cur = f.applyAsLong(cur));
}
if (!hasNextVal) {
hasMore = false;
}
}
return hasNextVal;
}
@Override
public long nextLong() {
if (!hasNextVal && !hasNext()) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
hasNextVal = false;
return cur;
}
});
}
/**
* Creates a stream that iterates from an initial value, applying a function to generate subsequent values.
*
* @param init the initial value
* @param f a function to apply to the previous element to generate the next element
* @return a LongStream of elements generated by the iteration
* @throws IllegalArgumentException if f is null
* @see Stream#iterate(Object, java.util.function.UnaryOperator)
*/
public static LongStream iterate(final long init, final LongUnaryOperator f) throws IllegalArgumentException {
N.checkArgNotNull(f);
return new IteratorLongStream(new LongIteratorEx() {
private long cur = 0;
private boolean isFirst = true;
@Override
public boolean hasNext() {
return true;
}
@Override
public long nextLong() {
if (isFirst) {
isFirst = false;
cur = init;
} else {
cur = f.applyAsLong(cur);
}
return cur;
}
});
}
/**
* Generates a LongStream using the provided LongSupplier.
* The supplier is used to generate each element of the stream.
*
* @param s the LongSupplier that provides the elements of the stream
* @return a LongStream generated by the given supplier
* @throws IllegalArgumentException if the supplier is null
* @see Stream#generate(Supplier)
*/
public static LongStream generate(final LongSupplier s) throws IllegalArgumentException {
N.checkArgNotNull(s);
return new IteratorLongStream(new LongIteratorEx() {
@Override
public boolean hasNext() {
return true;
}
@Override
public long nextLong() {
return s.getAsLong();
}
});
}
/**
* Concatenates multiple arrays of longs into a single LongStream.
*
* @param a the arrays of longs to concatenate
* @return a LongStream containing all the longs from the input arrays
* @see Stream#concat(Object[][])
*/
public static LongStream concat(final long[]... a) {
if (N.isEmpty(a)) {
return empty();
}
return concat(Arrays.asList(a));
}
/**
* Concatenates multiple LongIterators into a single LongStream.
*
* @param a the arrays of LongIterator to concatenate
* @return a LongStream containing all the longs from the input LongIterators
* @see Stream#concat(Iterator[])
*/
public static LongStream concat(final LongIterator... a) {
if (N.isEmpty(a)) {
return empty();
}
return concatIterators(Array.asList(a));
}
/**
* Concatenates multiple LongStreams into a single LongStream.
*
* @param a the arrays of LongStream to concatenate
* @return a LongStream containing all the longs from the input LongStreams
* @see Stream#concat(Stream[])
*/
public static LongStream concat(final LongStream... a) {
if (N.isEmpty(a)) {
return empty();
}
return concat(Array.asList(a));
}
/**
* Concatenates a list of long array into a single LongStream.
*
* @param c the list of long array to concatenate
* @return a LongStream containing all the longs from the input list of a long array
* @see Stream#concat(Object[][])
*/
@Beta
public static LongStream concat(final List c) {
if (N.isEmpty(c)) {
return empty();
}
return of(new LongIteratorEx() {
private final Iterator iter = c.iterator();
private long[] cur;
private int cursor = 0;
@Override
public boolean hasNext() {
while ((N.isEmpty(cur) || cursor >= cur.length) && iter.hasNext()) {
cur = iter.next();
cursor = 0;
}
return cur != null && cursor < cur.length;
}
@Override
public long nextLong() {
if ((cur == null || cursor >= cur.length) && !hasNext()) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
return cur[cursor++];
}
});
}
/**
* Concatenates a collection of LongStream into a single LongStream.
*
* @param streams the collection of LongStream to concatenate
* @return a LongStream containing all the longs from the input collection of LongStream
* @see Stream#concat(Collection)
*/
public static LongStream concat(final Collection streams) {
return N.isEmpty(streams) ? empty() : new IteratorLongStream(new LongIteratorEx() { //NOSONAR
private final Iterator iterators = streams.iterator();
private LongStream cur;
private LongIterator iter;
@Override
public boolean hasNext() {
while ((iter == null || !iter.hasNext()) && iterators.hasNext()) {
if (cur != null) {
cur.close();
}
cur = iterators.next();
iter = cur == null ? null : cur.iteratorEx();
}
return iter != null && iter.hasNext();
}
@Override
public long nextLong() {
if ((iter == null || !iter.hasNext()) && !hasNext()) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
return iter.nextLong();
}
}).onClose(newCloseHandler(streams));
}
/**
* Concatenates a collection of LongIterator into a single LongStream.
*
* @param longIterators the collection of LongIterator to concatenate
* @return a LongStream containing all the longs from the input collection of LongIterator
* @see Stream#concatIterators(Collection)
*/
@Beta
public static LongStream concatIterators(final Collection longIterators) {
if (N.isEmpty(longIterators)) {
return empty();
}
return new IteratorLongStream(new LongIteratorEx() {
private final Iterator iter = longIterators.iterator();
private LongIterator cur;
@Override
public boolean hasNext() {
while ((cur == null || !cur.hasNext()) && iter.hasNext()) {
cur = iter.next();
}
return cur != null && cur.hasNext();
}
@Override
public long nextLong() {
if ((cur == null || !cur.hasNext()) && !hasNext()) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
return cur.nextLong();
}
});
}
/**
* Zips two long arrays into a single LongStream until one of them runs out of values.
* Each pair of values is combined into a single value using the supplied zipFunction.
*
* @param a the first long array
* @param b the second long array
* @param zipFunction the function to combine elements from both arrays
* @return a LongStream containing the results of applying the zip function to the elements of the input arrays
* @see Stream#zip(Object[], Object[], BiFunction)
*/
public static LongStream zip(final long[] a, final long[] b, final LongBinaryOperator zipFunction) {
if (N.isEmpty(a) || N.isEmpty(b)) {
return empty();
}
return new IteratorLongStream(new LongIteratorEx() {
private final int len = N.min(N.len(a), N.len(b));
private int cursor = 0;
@Override
public boolean hasNext() {
return cursor < len;
}
@Override
public long nextLong() {
if (cursor >= len) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
return zipFunction.applyAsLong(a[cursor], b[cursor++]);
}
});
}
/**
* Zips three long arrays into a single LongStream until one of them runs out of values.
* Each triple of values is combined into a single value using the supplied zipFunction.
*
* @param a the first long array
* @param b the second long array
* @param c the third long array
* @param zipFunction the function to combine elements from all three arrays
* @return a LongStream containing the results of applying the zip function to the elements of the input arrays
* @see Stream#zip(Object[], Object[], Object[], TriFunction)
*/
public static LongStream zip(final long[] a, final long[] b, final long[] c, final LongTernaryOperator zipFunction) {
if (N.isEmpty(a) || N.isEmpty(b) || N.isEmpty(c)) {
return empty();
}
return new IteratorLongStream(new LongIteratorEx() {
private final int len = N.min(N.len(a), N.len(b), N.len(c));
private int cursor = 0;
@Override
public boolean hasNext() {
return cursor < len;
}
@Override
public long nextLong() {
if (cursor >= len) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
return zipFunction.applyAsLong(a[cursor], b[cursor], c[cursor++]);
}
});
}
/**
* Zips two LongIterators into a single LongStream until one of them runs out of values.
* Each pair of values is combined into a single value using the supplied zipFunction.
*
* @param a the first LongIterator
* @param b the second LongIterator
* @param zipFunction the function to combine elements from both iterators
* @return a LongStream containing the results of applying the zip function to the elements of the input iterators
* @see Stream#zip(Iterator, Iterator, BiFunction)
*/
public static LongStream zip(final LongIterator a, final LongIterator b, final LongBinaryOperator zipFunction) {
return new IteratorLongStream(new LongIteratorEx() {
private final LongIterator iterA = a == null ? LongIterator.empty() : a;
private final LongIterator iterB = b == null ? LongIterator.empty() : b;
@Override
public boolean hasNext() {
return iterA.hasNext() && iterB.hasNext();
}
@Override
public long nextLong() {
return zipFunction.applyAsLong(iterA.nextLong(), iterB.nextLong());
}
});
}
/**
* Zips three LongIterators into a single LongStream until one of them runs out of values.
* Each triple of values is combined into a single value using the supplied zipFunction.
*
* @param a the first LongIterator
* @param b the second LongIterator
* @param c the third LongIterator
* @param zipFunction the function to combine elements from all three iterators
* @return a LongStream containing the results of applying the zip function to the elements of the input iterators
* @see Stream#zip(Iterator, Iterator, Iterator, TriFunction)
*/
public static LongStream zip(final LongIterator a, final LongIterator b, final LongIterator c, final LongTernaryOperator zipFunction) {
return new IteratorLongStream(new LongIteratorEx() {
private final LongIterator iterA = a == null ? LongIterator.empty() : a;
private final LongIterator iterB = b == null ? LongIterator.empty() : b;
private final LongIterator iterC = c == null ? LongIterator.empty() : c;
@Override
public boolean hasNext() {
return iterA.hasNext() && iterB.hasNext() && iterC.hasNext();
}
@Override
public long nextLong() {
return zipFunction.applyAsLong(iterA.nextLong(), iterB.nextLong(), iterC.nextLong());
}
});
}
/**
* Zips two LongStreams into a single LongStream until one of them runs out of values.
* Each pair of values is combined into a single value using the supplied zipFunction.
*
* @param a the first LongStream
* @param b the second LongStream
* @param zipFunction the function to combine elements from both streams
* @return a LongStream containing the results of applying the zip function to the elements of the input streams
* @see Stream#zip(Stream, Stream, BiFunction)
*/
public static LongStream zip(final LongStream a, final LongStream b, final LongBinaryOperator zipFunction) {
return zip(iterate(a), iterate(b), zipFunction).onClose(newCloseHandler(a, b));
}
/**
* Zips three LongStreams into a single LongStream until one of them runs out of values.
* Each triple of values is combined into a single value using the supplied zipFunction.
*
* @param a the first LongStream
* @param b the second LongStream
* @param c the third LongStream
* @param zipFunction the function to combine elements from all three streams
* @return a LongStream containing the results of applying the zip function to the elements of the input streams
* @see Stream#zip(Stream, Stream, Stream, TriFunction)
*/
public static LongStream zip(final LongStream a, final LongStream b, final LongStream c, final LongTernaryOperator zipFunction) {
return zip(iterate(a), iterate(b), iterate(c), zipFunction).onClose(newCloseHandler(Array.asList(a, b, c)));
}
/**
* Zips multiple LongStreams into a single LongStream until one of them runs out of values.
* Each list of values is combined into a single value using the supplied zipFunction.
*
* @param streams the collection of LongStream to zip
* @param zipFunction the function to combine elements from all the streams
* @return a LongStream containing the results of applying the zip function to the elements of the input streams
* @see Stream#zip(Collection, Function)
*/
public static LongStream zip(final Collection streams, final LongNFunction zipFunction) {
//noinspection resource
return Stream.zip(streams, zipFunction).mapToLong(ToLongFunction.UNBOX);
}
/**
* Zips two long arrays into a single LongStream until all of them runs out of values.
* Each pair of values is combined into a single value using the supplied zipFunction.
* If one array runs out of values before the other, the specified valueForNoneA or valueForNoneB is used.
*
* @param a the first long array
* @param b the second long array
* @param valueForNoneA the default value to use if the first array is shorter
* @param valueForNoneB the default value to use if the second array is shorter
* @param zipFunction the function to combine elements from both arrays
* @return a LongStream containing the results of applying the zip function to the elements of the input arrays
* @see Stream#zip(Object[], Object[], Object, Object, BiFunction)
*/
public static LongStream zip(final long[] a, final long[] b, final long valueForNoneA, final long valueForNoneB, final LongBinaryOperator zipFunction) {
if (N.isEmpty(a) && N.isEmpty(b)) {
return empty();
}
return new IteratorLongStream(new LongIteratorEx() {
private final int aLen = N.len(a), bLen = N.len(b), len = N.max(aLen, bLen);
private int cursor = 0;
private long ret = 0;
@Override
public boolean hasNext() {
return cursor < len;
}
@Override
public long nextLong() {
if (cursor >= len) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
ret = zipFunction.applyAsLong(cursor < aLen ? a[cursor] : valueForNoneA, cursor < bLen ? b[cursor] : valueForNoneB);
cursor++;
return ret;
}
});
}
/**
* Zips three long arrays into a single LongStream until all of them runs out of values.
* Each triple of values is combined into a single value using the supplied zipFunction.
* If one array runs out of values before the other, the specified valueForNoneA, valueForNoneB or valueForNoneC is used.
*
* @param a the first long array
* @param b the second long array
* @param c the third long array
* @param valueForNoneA the default value to use if the first array is shorter
* @param valueForNoneB the default value to use if the second array is shorter
* @param valueForNoneC the default value to use if the third array is shorter
* @param zipFunction the function to combine elements from all three arrays
* @return a LongStream containing the results of applying the zip function to the elements of the input arrays
* @see Stream#zip(Object[], Object[], Object[], Object, Object, Object, TriFunction)
*/
public static LongStream zip(final long[] a, final long[] b, final long[] c, final long valueForNoneA, final long valueForNoneB, final long valueForNoneC,
final LongTernaryOperator zipFunction) {
if (N.isEmpty(a) && N.isEmpty(b) && N.isEmpty(c)) {
return empty();
}
return new IteratorLongStream(new LongIteratorEx() {
private final int aLen = N.len(a), bLen = N.len(b), cLen = N.len(c), len = N.max(aLen, bLen, cLen);
private int cursor = 0;
private long ret = 0;
@Override
public boolean hasNext() {
return cursor < len;
}
@Override
public long nextLong() {
if (cursor >= len) {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
ret = zipFunction.applyAsLong(cursor < aLen ? a[cursor] : valueForNoneA, cursor < bLen ? b[cursor] : valueForNoneB,
cursor < cLen ? c[cursor] : valueForNoneC);
cursor++;
return ret;
}
});
}
/**
* Zips two LongIterators into a single LongStream until all of them runs out of values.
* Each pair of values is combined into a single value using the supplied zipFunction.
* If one iterator runs out of values before the other, the specified valueForNoneA or valueForNoneB is used.
*
* @param a the first LongIterator
* @param b the second LongIterator
* @param valueForNoneA the default value to use if the first iterator is shorter
* @param valueForNoneB the default value to use if the second iterator is shorter
* @param zipFunction the function to combine elements from both iterators
* @return a LongStream containing the results of applying the zip function to the elements of the input iterators
* @see Stream#zip(Iterator, Iterator, Object, Object, BiFunction)
*/
public static LongStream zip(final LongIterator a, final LongIterator b, final long valueForNoneA, final long valueForNoneB,
final LongBinaryOperator zipFunction) {
return new IteratorLongStream(new LongIteratorEx() {
private final LongIterator iterA = a == null ? LongIterator.empty() : a;
private final LongIterator iterB = b == null ? LongIterator.empty() : b;
@Override
public boolean hasNext() {
return iterA.hasNext() || iterB.hasNext();
}
@Override
public long nextLong() {
if (iterA.hasNext()) {
return zipFunction.applyAsLong(iterA.nextLong(), iterB.hasNext() ? iterB.nextLong() : valueForNoneB);
} else {
return zipFunction.applyAsLong(valueForNoneA, iterB.nextLong());
}
}
});
}
/**
* Zips three LongIterators into a single LongStream until all of them runs out of values.
* Each triple of values is combined into a single value using the supplied zipFunction.
* If one iterator runs out of values before the other, the specified valueForNoneA, valueForNoneB or valueForNoneC is used.
*
* @param a the first LongIterator
* @param b the second LongIterator
* @param c the third LongIterator
* @param valueForNoneA the default value to use if the first iterator is shorter
* @param valueForNoneB the default value to use if the second iterator is shorter
* @param valueForNoneC the default value to use if the third iterator is shorter
* @param zipFunction the function to combine elements from all three iterators
* @return a LongStream containing the results of applying the zip function to the elements of the input iterators
* @see Stream#zip(Iterator, Iterator, Iterator, Object, Object, Object, TriFunction)
*/
public static LongStream zip(final LongIterator a, final LongIterator b, final LongIterator c, final long valueForNoneA, final long valueForNoneB,
final long valueForNoneC, final LongTernaryOperator zipFunction) {
return new IteratorLongStream(new LongIteratorEx() {
private final LongIterator iterA = a == null ? LongIterator.empty() : a;
private final LongIterator iterB = b == null ? LongIterator.empty() : b;
private final LongIterator iterC = c == null ? LongIterator.empty() : c;
@Override
public boolean hasNext() {
return iterA.hasNext() || iterB.hasNext() || iterC.hasNext();
}
@Override
public long nextLong() {
if (iterA.hasNext()) {
return zipFunction.applyAsLong(iterA.nextLong(), iterB.hasNext() ? iterB.nextLong() : valueForNoneB,
iterC.hasNext() ? iterC.nextLong() : valueForNoneC);
} else if (iterB.hasNext()) {
return zipFunction.applyAsLong(valueForNoneA, iterB.nextLong(), iterC.hasNext() ? iterC.nextLong() : valueForNoneC);
} else {
return zipFunction.applyAsLong(valueForNoneA, valueForNoneB, iterC.nextLong());
}
}
});
}
/**
* Zips two LongStreams into a single LongStream until all of them runs out of values.
* Each pair of values is combined into a single value using the supplied zipFunction.
* If one stream runs out of values before the other, the specified valueForNoneA or valueForNoneB is used.
*
* @param a the first LongStream
* @param b the second LongStream
* @param valueForNoneA the default value to use if the first stream is shorter
* @param valueForNoneB the default value to use if the second stream is shorter
* @param zipFunction the function to combine elements from both streams
* @return a LongStream containing the results of applying the zip function to the elements of the input streams
* @see Stream#zip(Stream, Stream, Object, Object, BiFunction)
*/
public static LongStream zip(final LongStream a, final LongStream b, final long valueForNoneA, final long valueForNoneB,
final LongBinaryOperator zipFunction) {
return zip(iterate(a), iterate(b), valueForNoneA, valueForNoneB, zipFunction).onClose(newCloseHandler(a, b));
}
/**
* Zips three LongStreams into a single LongStream until all of them runs out of values.
* Each triple of values is combined into a single value using the supplied zipFunction.
* If one stream runs out of values before the other, the specified valueForNoneA, valueForNoneB or valueForNoneC is used.
*
* @param a the first LongStream
* @param b the second LongStream
* @param c the third LongStream
* @param valueForNoneA the default value to use if the first stream is shorter
* @param valueForNoneB the default value to use if the second stream is shorter
* @param valueForNoneC the default value to use if the third stream is shorter
* @param zipFunction the function to combine elements from all three streams
* @return a LongStream containing the results of applying the zip function to the elements of the input streams
* @see Stream#zip(Stream, Stream, Stream, Object, Object, Object, TriFunction)
*/
public static LongStream zip(final LongStream a, final LongStream b, final LongStream c, final long valueForNoneA, final long valueForNoneB,
final long valueForNoneC, final LongTernaryOperator zipFunction) {
return zip(iterate(a), iterate(b), iterate(c), valueForNoneA, valueForNoneB, valueForNoneC, zipFunction)
.onClose(newCloseHandler(Array.asList(a, b, c)));
}
/**
* Zips multiple LongStreams into a single LongStream until all of them runs out of values.
* Each list of values is combined into a single value using the supplied zipFunction.
* If one stream runs out of values before the other, the specified valuesForNone is used.
*
* @param streams the collection of LongStream instances to zip
* @param valuesForNone the default value to use if the corresponding stream is shorter
* @param zipFunction the function to combine elements from all the streams
* @return a LongStream containing the results of applying the zip function to the elements of the input streams
* @see Stream#zip(Collection, List, Function)
*/
public static LongStream zip(final Collection streams, final long[] valuesForNone, final LongNFunction zipFunction) {
//noinspection resource
return Stream.zip(streams, valuesForNone, zipFunction).mapToLong(ToLongFunction.UNBOX);
}
/**
* Merges two long arrays into a single LongStream based on the provided nextSelector function.
* The nextSelector function determines which element to take next from the two arrays.
*
* @param a the first long array
* @param b the second long array
* @param nextSelector a function to determine which element should be selected as the next element.
* The first parameter is selected if {@code MergeResult.TAKE_FIRST} is returned, otherwise the second parameter is selected.
* @return a LongStream containing the merged elements from the two input arrays
* @see Stream#merge(Object[], Object[], BiFunction)
*/
public static LongStream merge(final long[] a, final long[] b, final LongBiFunction nextSelector) {
if (N.isEmpty(a)) {
return of(b);
} else if (N.isEmpty(b)) {
return of(a);
}
return new IteratorLongStream(new LongIteratorEx() {
private final int lenA = a.length;
private final int lenB = b.length;
private int cursorA = 0;
private int cursorB = 0;
@Override
public boolean hasNext() {
return cursorA < lenA || cursorB < lenB;
}
@Override
public long nextLong() {
if (cursorA < lenA) {
if ((cursorB >= lenB) || (nextSelector.apply(a[cursorA], b[cursorB]) == MergeResult.TAKE_FIRST)) {
return a[cursorA++];
} else {
return b[cursorB++];
}
} else if (cursorB < lenB) {
return b[cursorB++];
} else {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
}
});
}
/**
* Merges three long arrays into a single LongStream based on the provided nextSelector function.
* The nextSelector function determines which element to take next from the three arrays.
*
* @param a the first long array
* @param b the second long array
* @param c the third long array
* @param nextSelector a function to determine which element should be selected as the next element.
* The first parameter is selected if {@code MergeResult.TAKE_FIRST} is returned, otherwise the second parameter is selected.
* @return a LongStream containing the merged elements from the three input arrays
* @see Stream#merge(Object[], Object[], Object[], BiFunction)
*/
public static LongStream merge(final long[] a, final long[] b, final long[] c, final LongBiFunction nextSelector) {
//noinspection resource
return merge(merge(a, b, nextSelector).iteratorEx(), LongStream.of(c).iteratorEx(), nextSelector);
}
/**
* Merges two LongIterators into a single LongStream based on the provided nextSelector function.
* The nextSelector function determines which element to take next from the two iterators.
*
* @param a the first LongIterator
* @param b the second LongIterator
* @param nextSelector a function to determine which element should be selected as the next element.
* The first parameter is selected if {@code MergeResult.TAKE_FIRST} is returned, otherwise the second parameter is selected.
* @return a LongStream containing the merged elements from the two input iterators
* @see Stream#merge(Iterator, Iterator, BiFunction)
*/
public static LongStream merge(final LongIterator a, final LongIterator b, final LongBiFunction nextSelector) {
return new IteratorLongStream(new LongIteratorEx() {
private final LongIterator iterA = a == null ? LongIterator.empty() : a;
private final LongIterator iterB = b == null ? LongIterator.empty() : b;
private long nextA = 0;
private long nextB = 0;
private boolean hasNextA = false;
private boolean hasNextB = false;
@Override
public boolean hasNext() {
return iterA.hasNext() || iterB.hasNext() || hasNextA || hasNextB;
}
@Override
public long nextLong() {
if (hasNextA) {
if (iterB.hasNext()) {
if (nextSelector.apply(nextA, (nextB = iterB.nextLong())) == MergeResult.TAKE_FIRST) {
hasNextA = false;
hasNextB = true;
return nextA;
} else {
return nextB;
}
} else {
hasNextA = false;
return nextA;
}
} else if (hasNextB) {
if (iterA.hasNext()) {
if (nextSelector.apply((nextA = iterA.nextLong()), nextB) == MergeResult.TAKE_FIRST) {
return nextA;
} else {
hasNextA = true;
hasNextB = false;
return nextB;
}
} else {
hasNextB = false;
return nextB;
}
} else if (iterA.hasNext()) {
if (iterB.hasNext()) {
if (nextSelector.apply((nextA = iterA.nextLong()), (nextB = iterB.nextLong())) == MergeResult.TAKE_FIRST) {
hasNextB = true;
return nextA;
} else {
hasNextA = true;
return nextB;
}
} else {
return iterA.nextLong();
}
} else if (iterB.hasNext()) {
return iterB.nextLong();
} else {
throw new NoSuchElementException(ERROR_MSG_FOR_NO_SUCH_EX);
}
}
});
}
/**
* Merges three LongIterators into a single LongStream based on the provided nextSelector function.
* The nextSelector function determines which element to take next from the three iterators.
*
* @param a the first LongIterator
* @param b the second LongIterator
* @param c the third LongIterator
* @param nextSelector a function to determine which element should be selected as the next element.
* The first parameter is selected if {@code MergeResult.TAKE_FIRST} is returned, otherwise the second parameter is selected.
* @return a LongStream containing the merged elements from the three input iterators
* @see Stream#merge(Iterator, Iterator, Iterator, BiFunction)
*/
public static LongStream merge(final LongIterator a, final LongIterator b, final LongIterator c, final LongBiFunction nextSelector) {
//noinspection resource
return merge(merge(a, b, nextSelector).iteratorEx(), c, nextSelector);
}
/**
* Merges two LongStreams into a single LongStream based on the provided nextSelector function.
* The nextSelector function determines which element to take next from the two streams.
*
* @param a the first LongStream
* @param b the second LongStream
* @param nextSelector a function to determine which element should be selected as the next element.
* The first parameter is selected if {@code MergeResult.TAKE_FIRST} is returned, otherwise the second parameter is selected.
* @return a LongStream containing the merged elements from the two input streams
* @see Stream#merge(Stream, Stream, BiFunction)
*/
public static LongStream merge(final LongStream a, final LongStream b, final LongBiFunction nextSelector) {
return merge(iterate(a), iterate(b), nextSelector).onClose(newCloseHandler(a, b));
}
/**
* Merges three LongStreams into a single LongStream based on the provided nextSelector function.
* The nextSelector function determines which element to take next from the three streams.
*
* @param a the first LongStream
* @param b the second LongStream
* @param c the third LongStream
* @param nextSelector a function to determine which element should be selected as the next element.
* The first parameter is selected if {@code MergeResult.TAKE_FIRST} is returned, otherwise the second parameter is selected.
* @return a LongStream containing the merged elements from the three input streams
* @see Stream#merge(Stream, Stream, Stream, BiFunction)
*/
public static LongStream merge(final LongStream a, final LongStream b, final LongStream c, final LongBiFunction nextSelector) {
return merge(merge(a, b, nextSelector), c, nextSelector);
}
/**
* Merges a collection of LongStream into a single LongStream based on the provided nextSelector function.
* The nextSelector function determines which element to take next from the multiple streams.
*
* @param streams the collection of LongStream instances to merge
* @param nextSelector a function to determine which element should be selected as the next element.
* The first parameter is selected if {@code MergeResult.TAKE_FIRST} is returned, otherwise the second parameter is selected.
* @return a LongStream containing the merged elements from the input LongStreams
* @see Stream#merge(Collection, BiFunction)
*/
public static LongStream merge(final Collection streams, final LongBiFunction nextSelector) {
if (N.isEmpty(streams)) {
return empty();
} else if (streams.size() == 1) {
return streams.iterator().next();
} else if (streams.size() == 2) {
final Iterator iter = streams.iterator();
return merge(iter.next(), iter.next(), nextSelector);
}
final Iterator iter = streams.iterator();
LongStream result = merge(iter.next(), iter.next(), nextSelector);
while (iter.hasNext()) {
result = merge(result, iter.next(), nextSelector);
}
return result;
}
// /**
// * Merges a collection of LongStream into a single LongStream in parallel.
// * All the elements from each input LongStream will be merged into two queues by multiple threads first.
// * Then these two new queues will be merged into one LongStream in the current thread.
// * This method is not totally lazy evaluation and may cause {@code OutOfMemoryError} if there are too many elements merged into the two new queues.
// * Consider using {@code merge}, which is totally lazy evaluation.
// *
// * @param streams the collection of LongStream to be merged
// * @param nextSelector a function to determine which element should be selected as the next element.
// * @return a LongStream containing the merged elements from the input LongStreams
// * @see Stream#parallelMerge(Collection, BiFunction)
// */
// public static LongStream parallelMerge(final Collection streams, final LongBiFunction nextSelector) {
// return parallelMerge(streams, nextSelector, DEFAULT_MAX_THREAD_NUM);
// }
//
// /**
// * Merges a collection of LongStream into a single LongStream in parallel.
// * All the elements from each input LongStream will be merged into two queues by multiple threads first.
// * Then these two new queues will be merged into one LongStream in the current thread.
// * This method is not totally lazy evaluation and may cause {@code OutOfMemoryError} if there are too many elements merged into the two new queues.
// * Consider using {@code merge}, which is totally lazy evaluation.
// *
// * @param streams the collection of LongStream to be merged
// * @param nextSelector a function to determine which element should be selected as the next element.
// * @param maxThreadNum is the max thread number for the parallel merge.
// * @return a LongStream containing the merged elements from the input LongStreams
// * @see Stream#parallelMerge(Collection, BiFunction, int)
// */
// public static LongStream parallelMerge(final Collection streams, final LongBiFunction nextSelector,
// final int maxThreadNum) throws IllegalArgumentException {
// N.checkArgument(maxThreadNum > 0, "'maxThreadNum' must not be less than 1");
//
// if (maxThreadNum <= 1) {
// return merge(streams, nextSelector);
// } else if (N.isEmpty(streams)) {
// return empty();
// } else if (streams.size() == 1) {
// return streams.iterator().next();
// } else if (streams.size() == 2) {
// final Iterator iter = streams.iterator();
// return merge(iter.next(), iter.next(), nextSelector);
// } else if (streams.size() == 3) {
// final Iterator iter = streams.iterator();
// return merge(iter.next(), iter.next(), iter.next(), nextSelector);
// }
//
// final Supplier supplier = () -> {
// final Queue queue = N.newLinkedList();
//
// queue.addAll(streams);
//
// final Holder eHolder = new Holder<>();
// final MutableInt cnt = MutableInt.of(streams.size());
// final List> futureList = new ArrayList<>(streams.size() - 1);
//
// final int threadNum = N.min(maxThreadNum, streams.size() / 2 + 1);
//
// AsyncExecutor asyncExecutorToUse = checkAsyncExecutor(DEFAULT_ASYNC_EXECUTOR, threadNum, 0);
//
// for (int i = 0; i < threadNum; i++) {
// asyncExecutorToUse = execute(asyncExecutorToUse, threadNum, 0, i, futureList, () -> {
// LongStream a = null;
// LongStream b = null;
// LongStream c1 = null;
//
// try {
// while (eHolder.value() == null) {
// synchronized (queue) {
// if (cnt.value() > 2 && queue.size() > 1) {
// a = queue.poll();
// b = queue.poll();
//
// cnt.decrement();
// } else {
// break;
// }
// }
//
// c1 = LongStream.of(merge(a, b, nextSelector).toArray());
//
// synchronized (queue) {
// queue.offer(c1);
// }
// }
// } catch (final Throwable e) { // NOSONAR
// setError(eHolder, e);
// }
// });
// }
//
// completeAndShutdownTempExecutor(futureList, eHolder, streams, asyncExecutorToUse);
//
// return merge(queue.poll(), queue.poll(), nextSelector);
// };
//
// return Stream.just(supplier).flatMapToLong(Supplier::get);
// }
public abstract static class LongStreamEx extends LongStream {
private LongStreamEx(final boolean sorted, final Collection closeHandlers) { //NOSONAR
super(sorted, closeHandlers);
// Factory class.
}
}
}
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