LongStream (abacus-util 1.20.28 API)

java.lang.Object
- com.landawn.abacus.util.stream.LongStream

All Implemented Interfaces:

Immutable, BaseStream<Long,long[],LongPredicate,LongConsumer,LongList,u.OptionalLong,IndexedLong,LongIterator,LongStream>, AutoCloseable

Direct Known Subclasses:

LongStream.LongStreamEx
```
public abstract class LongStream
extends Object
```
The Stream will be automatically closed after execution(A terminal method is executed/triggered).

See Also:

BaseStream, Stream

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class LongStream.LongStreamEx
- Nested classes/interfaces inherited from interface com.landawn.abacus.util.stream.BaseStream
  BaseStream.Splitor

Nested Classes
Modifier and Type	Class and Description
`static class`	`LongStream.LongStreamEx`

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`<SS extends BaseStream> SS`	`__(Function<? super LongStream,SS> transfer)`
`abstract <E extends Exception> boolean`	`allMatch(Throwables.LongPredicate<E> predicate)`
`abstract <E extends Exception> boolean`	`anyMatch(Throwables.LongPredicate<E> predicate)`
`abstract LongStream`	`append(long... a)`
`abstract LongStream`	`appendIfEmpty(long... a)`
`abstract DoubleStream`	`asDoubleStream()`
`abstract FloatStream`	`asFloatStream()`
`abstract u.OptionalDouble`	`average()`
`abstract Stream<Long>`	`boxed()`
`S`	`carry(C action)` Same as `peek`
`void`	`close()`
`abstract Stream<LongList>`	`collapse(LongBiPredicate collapsible)` Merge series of adjacent elements which satisfy the given predicate using the merger function and return a new stream.
`abstract LongStream`	`collapse(LongBiPredicate collapsible, LongBinaryOperator mergeFunction)` Merge series of adjacent elements which satisfy the given predicate using the merger function and return a new stream.
`abstract <R> R`	`collect(Supplier<R> supplier, ObjLongConsumer<? super R> accumulator)`
`abstract <R> R`	`collect(Supplier<R> supplier, ObjLongConsumer<? super R> accumulator, BiConsumer<R,R> combiner)`
`static LongStream`	`concat(Collection<? extends LongStream> c)`
`static LongStream`	`concat(long[]... a)`
`static LongStream`	`concat(LongIterator... a)`
`static LongStream`	`concat(LongStream... a)`
`static LongStream`	`empty()`
`abstract <E extends Exception> u.OptionalLong`	`findAny(Throwables.LongPredicate<E> predicate)`
`abstract <E extends Exception> u.OptionalLong`	`findFirst(Throwables.LongPredicate<E> predicate)`
`abstract <E extends Exception,E2 extends Exception> u.OptionalLong`	`findFirstOrLast(Throwables.LongPredicate<E> predicateForFirst, Throwables.LongPredicate<E> predicateForLast)`
`abstract <E extends Exception> u.OptionalLong`	`findLast(Throwables.LongPredicate<E> predicate)` Consider using: `stream.reversed().findFirst(predicate)` for better performance if possible.
`abstract LongStream`	`flatMap(LongFunction<? extends LongStream> mapper)`
`abstract <T> Stream<T>`	`flatMappToObj(LongFunction<T[]> mapper)`
`abstract DoubleStream`	`flatMapToDouble(LongFunction<? extends DoubleStream> mapper)`
`abstract FloatStream`	`flatMapToFloat(LongFunction<? extends FloatStream> mapper)`
`abstract IntStream`	`flatMapToInt(LongFunction<? extends IntStream> mapper)`
`abstract <T> Stream<T>`	`flatMapToObj(LongFunction<? extends Stream<T>> mapper)`
`static LongStream`	`flatten(long[][] a)`
`static LongStream`	`flatten(long[][][] a)`
`static LongStream`	`flatten(long[][] a, boolean vertically)`
`static LongStream`	`flatten(long[][] a, long valueForNone, boolean vertically)`
`abstract LongStream`	`flattMap(LongFunction<long[]> mapper)`
`abstract <T> Stream<T>`	`flattMapToObj(LongFunction<? extends Collection<T>> mapper)`
`abstract <E extends Exception> void`	`forEach(Throwables.LongConsumer<E> action)`
`abstract <E extends Exception> void`	`forEachIndexed(Throwables.IndexedLongConsumer<E> action)`
`static LongStream`	`generate(LongSupplier s)`
`static LongStream`	`interval(long intervalInMillis)`
`static LongStream`	`interval(long delayInMillis, long intervalInMillis)` Generates the long value by the specified period: [0, 1, 2, 3...]
`static LongStream`	`interval(long delay, long interval, TimeUnit unit)` Generates the long value by the specified period: [0, 1, 2, 3...]
`boolean`	`isParallel()`
`static LongStream`	`iterate(BooleanSupplier hasNext, LongSupplier next)`
`static LongStream`	`iterate(long init, BooleanSupplier hasNext, LongUnaryOperator f)`
`static LongStream`	`iterate(long init, LongPredicate hasNext, LongUnaryOperator f)`
`static LongStream`	`iterate(long init, LongUnaryOperator f)`
`LongIterator`	`iterator()` Remember to close this Stream after the iteration is done, if needed.
`String`	`join(CharSequence delimiter)`
`abstract u.OptionalLong`	`kthLargest(int k)`
`abstract LongStream`	`map(LongUnaryOperator mapper)`
`abstract DoubleStream`	`mapToDouble(LongToDoubleFunction mapper)`
`abstract FloatStream`	`mapToFloat(LongToFloatFunction mapper)`
`abstract IntStream`	`mapToInt(LongToIntFunction mapper)`
`abstract <U> Stream<U>`	`mapToObj(LongFunction<? extends U> mapper)`
`abstract u.OptionalLong`	`max()`
`static LongStream`	`merge(Collection<? extends LongStream> c, LongBiFunction<MergeResult> nextSelector)`
`static LongStream`	`merge(long[] a, long[] b, long[] c, LongBiFunction<MergeResult> nextSelector)`
`static LongStream`	`merge(long[] a, long[] b, LongBiFunction<MergeResult> nextSelector)`
`static LongStream`	`merge(LongIterator a, LongIterator b, LongBiFunction<MergeResult> nextSelector)`
`static LongStream`	`merge(LongIterator a, LongIterator b, LongIterator c, LongBiFunction<MergeResult> nextSelector)`
`abstract LongStream`	`merge(LongStream b, LongBiFunction<MergeResult> nextSelector)`
`static LongStream`	`merge(LongStream a, LongStream b, LongBiFunction<MergeResult> nextSelector)`
`static LongStream`	`merge(LongStream a, LongStream b, LongStream c, LongBiFunction<MergeResult> nextSelector)`
`abstract u.OptionalLong`	`min()`
`abstract <E extends Exception> boolean`	`noneMatch(Throwables.LongPredicate<E> predicate)`
`static LongStream`	`of(Collection<Long> c)`
`static LongStream`	`of(long... a)`
`static LongStream`	`of(Long[] a)`
`static LongStream`	`of(long[] a, int startIndex, int endIndex)`
`static LongStream`	`of(Long[] a, int startIndex, int endIndex)`
`static LongStream`	`of(LongIterator iterator)`
`static LongStream`	`of(LongStream stream)`
`static LongStream`	`of(Supplier<LongList> supplier)` Lazy evaluation.
`S`	`parallel()`
`S`	`parallel(BaseStream.Splitor splitor)`
`S`	`parallel(Executor executor)`
`S`	`parallel(int maxThreadNum)`
`S`	`parallel(int maxThreadNum, BaseStream.Splitor splitor)` Returns an equivalent stream that is parallel.
`S`	`parallel(int maxThreadNum, BaseStream.Splitor splitor, Executor executor)`
`S`	`parallel(int maxThreadNum, Executor executor)`
`static LongStream`	`parallelMerge(Collection<? extends LongStream> c, LongBiFunction<MergeResult> nextSelector)`
`static LongStream`	`parallelMerge(Collection<? extends LongStream> c, LongBiFunction<MergeResult> nextSelector, int maxThreadNum)`
`abstract LongStream`	`prepend(long... a)`
`void`	`println()`
`static LongStream`	`random()`
`static LongStream`	`range(long startInclusive, long endExclusive)`
`static LongStream`	`range(long startInclusive, long endExclusive, long by)`
`static LongStream`	`rangeClosed(long startInclusive, long endInclusive)`
`static LongStream`	`rangeClosed(long startInclusive, long endInclusive, long by)`
`abstract LongStream`	`rangeMap(LongBiPredicate sameRange, LongBinaryOperator mapper)` Note: copied from StreamEx: https://github.com/amaembo/streamex Returns a stream consisting of results of applying the given function to the ranges created from the source elements.
`abstract <T> Stream<T>`	`rangeMapToObj(LongBiPredicate sameRange, LongBiFunction<T> mapper)` Note: copied from StreamEx: https://github.com/amaembo/streamex Returns a stream consisting of results of applying the given function to the ranges created from the source elements.
`abstract u.OptionalLong`	`reduce(LongBinaryOperator op)`
`abstract long`	`reduce(long identity, LongBinaryOperator op)`
`static LongStream`	`repeat(long element, long n)`
`abstract LongStream`	`scan(LongBinaryOperator accumulator)` Returns a `Stream` produced by iterative application of a accumulation function to an initial element `init` and next element of the current stream.
`abstract LongStream`	`scan(long init, LongBinaryOperator accumulator)` Returns a `Stream` produced by iterative application of a accumulation function to an initial element `init` and next element of the current stream.
`abstract LongStream`	`scan(long init, LongBinaryOperator accumulator, boolean initIncluded)`
`S`	`sequential()`
`S`	`shuffled()` This method only run sequentially, even in parallel stream and all elements will be loaded to memory.
`LongStream`	`skipUntil(LongPredicate predicate)`
`Stream<S>`	`sliding(int windowSize)`
`Stream<PL>`	`slidingToList(int windowSize)`
`abstract long`	`sum()`
`abstract LongSummaryStatistics`	`summarize()`
`abstract Pair<LongSummaryStatistics,u.Optional<Map<Percentage,Long>>>`	`summarizeAndPercentiles()`
`ImmutableList<T>`	`toImmutableList()`
`ImmutableSet<T>`	`toImmutableSet()`
`abstract LongStream`	`toJdkStream()`
`abstract LongList`	`toLongList()`
`abstract <K,A,D> Map<K,D>`	`toMap(LongFunction<? extends K> keyMapper, Collector<Long,A,D> downstream)`
`abstract <K,A,D,M extends Map<K,D>> M`	`toMap(LongFunction<? extends K> keyMapper, Collector<Long,A,D> downstream, Supplier<? extends M> mapFactory)`
`abstract <K,V> Map<K,V>`	`toMap(LongFunction<? extends K> keyMapper, LongFunction<? extends V> valueMapper)`
`abstract <K,V> Map<K,V>`	`toMap(LongFunction<? extends K> keyMapper, LongFunction<? extends V> valueMapper, BinaryOperator<V> mergeFunction)`
`abstract <K,V,M extends Map<K,V>> M`	`toMap(LongFunction<? extends K> keyMapper, LongFunction<? extends V> valueMapper, BinaryOperator<V> mergeFunction, Supplier<? extends M> mapFactory)`
`abstract <K,V,M extends Map<K,V>> M`	`toMap(LongFunction<? extends K> keyMapper, LongFunction<? extends V> valueMapper, Supplier<? extends M> mapFactory)`
`abstract LongStream`	`top(int n)` This method only run sequentially, even in parallel stream.
`abstract LongStream`	`top(int n, Comparator<? super Long> comparator)` This method only run sequentially, even in parallel stream.
`static LongStream`	`zip(Collection<? extends LongStream> c, long[] valuesForNone, LongNFunction<Long> zipFunction)` Zip together the iterators until all of them runs out of values.
`static LongStream`	`zip(Collection<? extends LongStream> c, LongNFunction<Long> zipFunction)` Zip together the iterators until one of them runs out of values.
`static LongStream`	`zip(long[] a, long[] b, long[] c, long valueForNoneA, long valueForNoneB, long valueForNoneC, LongTernaryOperator zipFunction)` Zip together the "a", "b" and "c" iterators until all of them runs out of values.
`static LongStream`	`zip(long[] a, long[] b, long[] c, LongTernaryOperator zipFunction)` Zip together the "a", "b" and "c" arrays until one of them runs out of values.
`static LongStream`	`zip(long[] a, long[] b, LongBinaryOperator zipFunction)` Zip together the "a" and "b" arrays until one of them runs out of values.
`static LongStream`	`zip(long[] a, long[] b, long valueForNoneA, long valueForNoneB, LongBinaryOperator zipFunction)` Zip together the "a" and "b" iterators until all of them runs out of values.
`static LongStream`	`zip(LongIterator a, LongIterator b, LongBinaryOperator zipFunction)` Zip together the "a" and "b" iterators until one of them runs out of values.
`static LongStream`	`zip(LongIterator a, LongIterator b, LongIterator c, long valueForNoneA, long valueForNoneB, long valueForNoneC, LongTernaryOperator zipFunction)` Zip together the "a", "b" and "c" iterators until all of them runs out of values.
`static LongStream`	`zip(LongIterator a, LongIterator b, LongIterator c, LongTernaryOperator zipFunction)` Zip together the "a", "b" and "c" iterators until one of them runs out of values.
`static LongStream`	`zip(LongIterator a, LongIterator b, long valueForNoneA, long valueForNoneB, LongBinaryOperator zipFunction)` Zip together the "a" and "b" iterators until all of them runs out of values.
`static LongStream`	`zip(LongStream a, LongStream b, LongBinaryOperator zipFunction)` Zip together the "a" and "b" streams until one of them runs out of values.
`static LongStream`	`zip(LongStream a, LongStream b, long valueForNoneA, long valueForNoneB, LongBinaryOperator zipFunction)` Zip together the "a" and "b" iterators until all of them runs out of values.
`static LongStream`	`zip(LongStream a, LongStream b, LongStream c, long valueForNoneA, long valueForNoneB, long valueForNoneC, LongTernaryOperator zipFunction)` Zip together the "a", "b" and "c" iterators until all of them runs out of values.
`static LongStream`	`zip(LongStream a, LongStream b, LongStream c, LongTernaryOperator zipFunction)` Zip together the "a", "b" and "c" streams until one of them runs out of values.
`abstract LongStream`	`zipWith(LongStream b, LongBinaryOperator zipFunction)`
`abstract LongStream`	`zipWith(LongStream b, long valueForNoneA, long valueForNoneB, LongBinaryOperator zipFunction)`
`abstract LongStream`	`zipWith(LongStream b, LongStream c, long valueForNoneA, long valueForNoneB, long valueForNoneC, LongTernaryOperator zipFunction)`
`abstract LongStream`	`zipWith(LongStream b, LongStream c, LongTernaryOperator zipFunction)`

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.landawn.abacus.util.stream.BaseStream
acceptIfNotEmpty, append, appendIfEmpty, applyIfNotEmpty, count, difference, distinct, dropWhile, dropWhile, filter, filter, first, indexed, intersection, join, last, limit, onClose, onlyOne, peek, percentiles, prepend, removeIf, removeIf, reversed, reverseSorted, rotated, shuffled, skip, skip, sliding, slidingToList, sorted, split, split, splitAt, splitBy, splitToList, splitToList, step, symmetricDifference, takeWhile, toArray, toCollection, toList, toLongMultiset, toLongMultiset, toMultiset, toMultiset, toSet

Method Detail

skipUntil

@ParallelSupported
 @IntermediateOp
 @Beta
public LongStream skipUntil(LongPredicate predicate)

map

public abstract LongStream map(LongUnaryOperator mapper)

mapToInt

public abstract IntStream mapToInt(LongToIntFunction mapper)

mapToFloat

public abstract FloatStream mapToFloat(LongToFloatFunction mapper)

mapToDouble

public abstract DoubleStream mapToDouble(LongToDoubleFunction mapper)

mapToObj

public abstract <U> Stream<U> mapToObj(LongFunction<? extends U> mapper)

flatMap

public abstract LongStream flatMap(LongFunction<? extends LongStream> mapper)

flattMap

public abstract LongStream flattMap(LongFunction<long[]> mapper)

flatMapToInt

public abstract IntStream flatMapToInt(LongFunction<? extends IntStream> mapper)

flatMapToFloat

public abstract FloatStream flatMapToFloat(LongFunction<? extends FloatStream> mapper)

flatMapToDouble

public abstract DoubleStream flatMapToDouble(LongFunction<? extends DoubleStream> mapper)

flatMapToObj

public abstract <T> Stream<T> flatMapToObj(LongFunction<? extends Stream<T>> mapper)

flattMapToObj

public abstract <T> Stream<T> flattMapToObj(LongFunction<? extends Collection<T>> mapper)

flatMappToObj

public abstract <T> Stream<T> flatMappToObj(LongFunction<T[]> mapper)

rangeMap
```
@SequentialOnly
public abstract LongStream rangeMap(LongBiPredicate sameRange,
                                                     LongBinaryOperator mapper)
```
Note: copied from StreamEx: https://github.com/amaembo/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.

Parameters:

sameRange - a non-interfering, stateless predicate to apply to the leftmost and next elements which returns true for elements which belong to the same range.

mapper - a non-interfering, stateless function to apply to the range borders and produce the resulting element. If 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.

Returns:

See Also:

collapse(LongBiPredicate, LongBinaryOperator), Stream.rangeMap(BiPredicate, BiFunction)

rangeMapToObj
```
@SequentialOnly
public abstract <T> Stream<T> rangeMapToObj(LongBiPredicate sameRange,
                                                             LongBiFunction<T> mapper)
```
Note: copied from StreamEx: https://github.com/amaembo/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.

Parameters:

sameRange - a non-interfering, stateless predicate to apply to the leftmost and next elements which returns true for elements which belong to the same range.

mapper - a non-interfering, stateless function to apply to the range borders and produce the resulting element. If 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.

Returns:

See Also:

Stream.rangeMap(BiPredicate, BiFunction)

collapse
```
@SequentialOnly
public abstract Stream<LongList> collapse(LongBiPredicate collapsible)
```
Merge series of adjacent elements which satisfy the given predicate using the merger function and return a new stream.
This method only run sequentially, even in parallel stream.

Parameters:

collapsible -

Returns:

collapse

@SequentialOnly
public abstract LongStream collapse(LongBiPredicate collapsible,
                                                     LongBinaryOperator mergeFunction)

Merge series of adjacent elements which satisfy the given predicate using the merger function and return a new stream.
This method only run sequentially, even in parallel stream.

Parameters:: collapsible -; mergeFunction -
Returns:

scan
```
@SequentialOnly
public abstract LongStream scan(LongBinaryOperator accumulator)
```
Returns a Stream produced by iterative application of a accumulation function to an initial element init and next element of the current stream. Produces a Stream consisting of init, acc(init, value1), acc(acc(init, value1), value2), etc.
This is an intermediate operation.
Example:
```
 accumulator: (a, b) -> a + b
 stream: [1, 2, 3, 4, 5]
 result: [1, 3, 6, 10, 15]
 
```
This method only run sequentially, even in parallel stream.
Parameters:

accumulator - the accumulation function

Returns:

scan
```
@SequentialOnly
public abstract LongStream scan(long init,
                                                 LongBinaryOperator accumulator)
```
Returns a Stream produced by iterative application of a accumulation function to an initial element init and next element of the current stream. Produces a Stream consisting of init, acc(init, value1), acc(acc(init, value1), value2), etc.
This is an intermediate operation.
Example:
```
 init:10
 accumulator: (a, b) -> a + b
 stream: [1, 2, 3, 4, 5]
 result: [11, 13, 16, 20, 25]
 
```
This method only run sequentially, even in parallel stream.
Parameters:

init - the initial value. it's only used once by accumulator to calculate the fist 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.

accumulator - the accumulation function

Returns:

scan

@SequentialOnly
public abstract LongStream scan(long init,
                                                 LongBinaryOperator accumulator,
                                                 boolean initIncluded)

Parameters:: init -; accumulator -; initIncluded -
Returns:

prepend

public abstract LongStream prepend(long... a)

append

public abstract LongStream append(long... a)

appendIfEmpty

public abstract LongStream appendIfEmpty(long... a)

top
```
@SequentialOnly
public abstract LongStream top(int n)
```
This method only run sequentially, even in parallel stream.

Parameters:

n -

Returns:

top

@SequentialOnly
public abstract LongStream top(int n,
                                                Comparator<? super Long> comparator)

This method only run sequentially, even in parallel stream.

Parameters:: n -
Returns:

toLongList
```
public abstract LongList toLongList()
```

toMap

public abstract <K,V> Map<K,V> toMap(LongFunction<? extends K> keyMapper,
                                     LongFunction<? extends V> valueMapper)

Parameters:: keyMapper -; valueMapper -
Returns:
See Also:: Collectors.toMap(Function, Function)

toMap

public abstract <K,V,M extends Map<K,V>> M toMap(LongFunction<? extends K> keyMapper,
                                                 LongFunction<? extends V> valueMapper,
                                                 Supplier<? extends M> mapFactory)

Parameters:: keyMapper -; valueMapper -; mapFactory -
Returns:
See Also:: Collectors.toMap(Function, Function, Supplier)

toMap

public abstract <K,V> Map<K,V> toMap(LongFunction<? extends K> keyMapper,
                                     LongFunction<? extends V> valueMapper,
                                     BinaryOperator<V> mergeFunction)

Parameters:: keyMapper -; valueMapper -; mergeFunction -
Returns:
See Also:: Collectors.toMap(Function, Function, BinaryOperator)

toMap

public abstract <K,V,M extends Map<K,V>> M toMap(LongFunction<? extends K> keyMapper,
                                                 LongFunction<? extends V> valueMapper,
                                                 BinaryOperator<V> mergeFunction,
                                                 Supplier<? extends M> mapFactory)

Parameters:: keyMapper -; valueMapper -; mergeFunction -; mapFactory -
Returns:
See Also:: Collectors.toMap(Function, Function, BinaryOperator, Supplier)

toMap

public abstract <K,A,D> Map<K,D> toMap(LongFunction<? extends K> keyMapper,
                                       Collector<Long,A,D> downstream)

Parameters:: keyMapper -; downstream -
Returns:
See Also:: Collectors.groupingBy(Function, Collector)

toMap

public abstract <K,A,D,M extends Map<K,D>> M toMap(LongFunction<? extends K> keyMapper,
                                                   Collector<Long,A,D> downstream,
                                                   Supplier<? extends M> mapFactory)

Parameters:: keyMapper -; downstream -; mapFactory -
Returns:
See Also:: Collectors.groupingBy(Function, Collector, Supplier)

reduce

public abstract long reduce(long identity,
                            LongBinaryOperator op)

reduce

public abstract u.OptionalLong reduce(LongBinaryOperator op)

collect

public abstract <R> R collect(Supplier<R> supplier,
                              ObjLongConsumer<? super R> accumulator,
                              BiConsumer<R,R> combiner)

collect

public abstract <R> R collect(Supplier<R> supplier,
                              ObjLongConsumer<? super R> accumulator)

Parameters:: supplier -; accumulator -
Returns:

forEach

@ParallelSupported
 @TerminalOp
public abstract <E extends Exception> void forEach(Throwables.LongConsumer<E> action)
                                                                              throws E extends Exception

Throws:: E extends Exception

forEachIndexed

@ParallelSupported
 @TerminalOp
public abstract <E extends Exception> void forEachIndexed(Throwables.IndexedLongConsumer<E> action)
                                                                                     throws E extends Exception

Throws:: E extends Exception

anyMatch

public abstract <E extends Exception> boolean anyMatch(Throwables.LongPredicate<E> predicate)
                                                throws E extends Exception

Throws:: E extends Exception

allMatch

public abstract <E extends Exception> boolean allMatch(Throwables.LongPredicate<E> predicate)
                                                throws E extends Exception

Throws:: E extends Exception

noneMatch

public abstract <E extends Exception> boolean noneMatch(Throwables.LongPredicate<E> predicate)
                                                 throws E extends Exception

Throws:: E extends Exception

findFirst

public abstract <E extends Exception> u.OptionalLong findFirst(Throwables.LongPredicate<E> predicate)
                                                        throws E extends Exception

Throws:: E extends Exception

findLast

public abstract <E extends Exception> u.OptionalLong findLast(Throwables.LongPredicate<E> predicate)
                                                       throws E extends Exception

Consider using: stream.reversed().findFirst(predicate) for better performance if possible.

Type Parameters:: E -
Parameters:: predicate -
Returns:
Throws:: E; E extends Exception

findFirstOrLast

public abstract <E extends Exception,E2 extends Exception> u.OptionalLong findFirstOrLast(Throwables.LongPredicate<E> predicateForFirst,
                                                                                          Throwables.LongPredicate<E> predicateForLast)
                                                                                   throws E extends Exception,
                                                                                          E2 extends Exception

Throws:: E extends Exception

findAny

public abstract <E extends Exception> u.OptionalLong findAny(Throwables.LongPredicate<E> predicate)
                                                      throws E extends Exception

Throws:: E extends Exception

min
```
public abstract u.OptionalLong min()
```

max
```
public abstract u.OptionalLong max()
```

kthLargest
```
public abstract u.OptionalLong kthLargest(int k)
```
Parameters:

k -

Returns:

OptionalByte.empty() if there is no element or count less than k, otherwise the kth largest element.

sum
```
public abstract long sum()
```

average

public abstract u.OptionalDouble average()

summarize

public abstract LongSummaryStatistics summarize()

summarizeAndPercentiles

public abstract Pair<LongSummaryStatistics,u.Optional<Map<Percentage,Long>>> summarizeAndPercentiles()

merge

public abstract LongStream merge(LongStream b,
                                 LongBiFunction<MergeResult> nextSelector)

Parameters:: b -; nextSelector - first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected.
Returns:

zipWith

public abstract LongStream zipWith(LongStream b,
                                   LongBinaryOperator zipFunction)

zipWith

public abstract LongStream zipWith(LongStream b,
                                   LongStream c,
                                   LongTernaryOperator zipFunction)

zipWith

public abstract LongStream zipWith(LongStream b,
                                   long valueForNoneA,
                                   long valueForNoneB,
                                   LongBinaryOperator zipFunction)

zipWith

public abstract LongStream zipWith(LongStream b,
                                   LongStream c,
                                   long valueForNoneA,
                                   long valueForNoneB,
                                   long valueForNoneC,
                                   LongTernaryOperator zipFunction)

asFloatStream

public abstract FloatStream asFloatStream()

asDoubleStream

public abstract DoubleStream asDoubleStream()

toJdkStream

public abstract LongStream toJdkStream()

boxed
```
public abstract Stream<Long> boxed()
```

iterator
```
@SequentialOnly
public LongIterator iterator()
```
Remember to close this Stream after the iteration is done, if needed.

Returns:

__

@SequentialOnly
 @IntermediateOp
 @Beta
public <SS extends BaseStream> SS __(Function<? super LongStream,SS> transfer)

empty
```
public static LongStream empty()
```

of

@SafeVarargs
public static LongStream of(long... a)

of

public static LongStream of(long[] a,
                            int startIndex,
                            int endIndex)

of

public static LongStream of(Long[] a)

of

public static LongStream of(Long[] a,
                            int startIndex,
                            int endIndex)

of

public static LongStream of(Collection<Long> c)

of

public static LongStream of(LongIterator iterator)

of

public static LongStream of(Supplier<LongList> supplier)

Lazy evaluation.

Parameters:: supplier -
Returns:

of

public static LongStream of(LongStream stream)

flatten

public static LongStream flatten(long[][] a)

flatten

public static LongStream flatten(long[][] a,
                                 boolean vertically)

flatten

public static LongStream flatten(long[][] a,
                                 long valueForNone,
                                 boolean vertically)

flatten

public static LongStream flatten(long[][][] a)

range

public static LongStream range(long startInclusive,
                               long endExclusive)

range

public static LongStream range(long startInclusive,
                               long endExclusive,
                               long by)

rangeClosed

public static LongStream rangeClosed(long startInclusive,
                                     long endInclusive)

rangeClosed

public static LongStream rangeClosed(long startInclusive,
                                     long endInclusive,
                                     long by)

repeat

public static LongStream repeat(long element,
                                long n)

random
```
public static LongStream random()
```

iterate

public static LongStream iterate(BooleanSupplier hasNext,
                                 LongSupplier next)

iterate

public static LongStream iterate(long init,
                                 BooleanSupplier hasNext,
                                 LongUnaryOperator f)

iterate

public static LongStream iterate(long init,
                                 LongPredicate hasNext,
                                 LongUnaryOperator f)

Parameters:: init -; hasNext - test if has next by hasNext.test(init) for first time and hasNext.test(f.apply(previous)) for remaining.; f -
Returns:

iterate

public static LongStream iterate(long init,
                                 LongUnaryOperator f)

generate

public static LongStream generate(LongSupplier s)

interval

public static LongStream interval(long intervalInMillis)

Parameters:: intervalInMillis -
Returns:

interval
```
public static LongStream interval(long delayInMillis,
                                  long intervalInMillis)
```
Generates the long value by the specified period: [0, 1, 2, 3...]

Parameters:

delayInMillis -

intervalInMillis -

Returns:

interval

public static LongStream interval(long delay,
                                  long interval,
                                  TimeUnit unit)

Generates the long value by the specified period: [0, 1, 2, 3...]

Parameters:: delay -; interval -; unit -
Returns:

concat

@SafeVarargs
public static LongStream concat(long[]... a)

concat

@SafeVarargs
public static LongStream concat(LongIterator... a)

concat

@SafeVarargs
public static LongStream concat(LongStream... a)

concat

public static LongStream concat(Collection<? extends LongStream> c)

zip
```
public static LongStream zip(long[] a,
                             long[] b,
                             LongBinaryOperator zipFunction)
```
Zip together the "a" and "b" arrays until one of them runs out of values. Each pair of values is combined into a single value using the supplied zipFunction function.

Parameters:

a -

b -

Returns:

zip

public static LongStream zip(long[] a,
                             long[] b,
                             long[] c,
                             LongTernaryOperator zipFunction)

Zip together the "a", "b" and "c" arrays until one of them runs out of values. Each triple of values is combined into a single value using the supplied zipFunction function.

Parameters:: a -; b -; c -
Returns:

zip

public static LongStream zip(LongIterator a,
                             LongIterator b,
                             LongBinaryOperator zipFunction)

Zip together the "a" and "b" iterators until one of them runs out of values. Each pair of values is combined into a single value using the supplied zipFunction function.

Parameters:: a -; b -
Returns:

zip

public static LongStream zip(LongIterator a,
                             LongIterator b,
                             LongIterator c,
                             LongTernaryOperator zipFunction)

Zip together the "a", "b" and "c" iterators until one of them runs out of values. Each triple of values is combined into a single value using the supplied zipFunction function.

Parameters:: a -; b -
Returns:

zip

public static LongStream zip(LongStream a,
                             LongStream b,
                             LongBinaryOperator zipFunction)

Zip together the "a" and "b" streams until one of them runs out of values. Each pair of values is combined into a single value using the supplied zipFunction function.

Parameters:: a -; b -
Returns:

zip

public static LongStream zip(LongStream a,
                             LongStream b,
                             LongStream c,
                             LongTernaryOperator zipFunction)

Zip together the "a", "b" and "c" streams until one of them runs out of values. Each triple of values is combined into a single value using the supplied zipFunction function.

Parameters:: a -; b -
Returns:

zip
```
public static LongStream zip(Collection<? extends LongStream> c,
                             LongNFunction<Long> zipFunction)
```
Zip together the iterators until one of them runs out of values. Each array of values is combined into a single value using the supplied zipFunction function.

Parameters:

c -

zipFunction -

Returns:

zip
```
public static LongStream zip(long[] a,
                             long[] b,
                             long valueForNoneA,
                             long valueForNoneB,
                             LongBinaryOperator zipFunction)
```
Zip together the "a" and "b" iterators until all of them runs out of values. Each pair of values is combined into a single value using the supplied zipFunction function.

Parameters:

a -

b -

valueForNoneA - value to fill if "a" runs out of values first.

valueForNoneB - value to fill if "b" runs out of values first.

zipFunction -

Returns:

zip
```
public static LongStream zip(long[] a,
                             long[] b,
                             long[] c,
                             long valueForNoneA,
                             long valueForNoneB,
                             long valueForNoneC,
                             LongTernaryOperator zipFunction)
```
Zip together the "a", "b" and "c" iterators until all of them runs out of values. Each triple of values is combined into a single value using the supplied zipFunction function.

Parameters:

a -

b -

c -

valueForNoneA - value to fill if "a" runs out of values.

valueForNoneB - value to fill if "b" runs out of values.

valueForNoneC - value to fill if "c" runs out of values.

zipFunction -

Returns:

zip
```
public static LongStream zip(LongIterator a,
                             LongIterator b,
                             long valueForNoneA,
                             long valueForNoneB,
                             LongBinaryOperator zipFunction)
```
Zip together the "a" and "b" iterators until all of them runs out of values. Each pair of values is combined into a single value using the supplied zipFunction function.

Parameters:

a -

b -

valueForNoneA - value to fill if "a" runs out of values first.

valueForNoneB - value to fill if "b" runs out of values first.

zipFunction -

Returns:

zip

public static LongStream zip(LongIterator a,
                             LongIterator b,
                             LongIterator c,
                             long valueForNoneA,
                             long valueForNoneB,
                             long valueForNoneC,
                             LongTernaryOperator zipFunction)

Zip together the "a", "b" and "c" iterators until all of them runs out of values. Each triple of values is combined into a single value using the supplied zipFunction function.

Parameters:: a -; b -; c -; valueForNoneA - value to fill if "a" runs out of values.; valueForNoneB - value to fill if "b" runs out of values.; valueForNoneC - value to fill if "c" runs out of values.; zipFunction -
Returns:

zip
```
public static LongStream zip(LongStream a,
                             LongStream b,
                             long valueForNoneA,
                             long valueForNoneB,
                             LongBinaryOperator zipFunction)
```
Zip together the "a" and "b" iterators until all of them runs out of values. Each pair of values is combined into a single value using the supplied zipFunction function.

Parameters:

a -

b -

valueForNoneA - value to fill if "a" runs out of values first.

valueForNoneB - value to fill if "b" runs out of values first.

zipFunction -

Returns:

zip

public static LongStream zip(LongStream a,
                             LongStream b,
                             LongStream c,
                             long valueForNoneA,
                             long valueForNoneB,
                             long valueForNoneC,
                             LongTernaryOperator zipFunction)

Zip together the "a", "b" and "c" iterators until all of them runs out of values. Each triple of values is combined into a single value using the supplied zipFunction function.

Parameters:: a -; b -; c -; valueForNoneA - value to fill if "a" runs out of values.; valueForNoneB - value to fill if "b" runs out of values.; valueForNoneC - value to fill if "c" runs out of values.; zipFunction -
Returns:

zip
```
public static LongStream zip(Collection<? extends LongStream> c,
                             long[] valuesForNone,
                             LongNFunction<Long> zipFunction)
```
Zip together the iterators until all of them runs out of values. Each array of values is combined into a single value using the supplied zipFunction function.

Parameters:

c -

valuesForNone - value to fill for any iterator runs out of values.

zipFunction -

Returns:

merge

public static LongStream merge(long[] a,
                               long[] b,
                               LongBiFunction<MergeResult> nextSelector)

Parameters:: a -; b -; nextSelector - first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected.
Returns:

merge

public static LongStream merge(long[] a,
                               long[] b,
                               long[] c,
                               LongBiFunction<MergeResult> nextSelector)

Parameters:: a -; b -; c -; nextSelector - first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected.
Returns:

merge

public static LongStream merge(LongIterator a,
                               LongIterator b,
                               LongBiFunction<MergeResult> nextSelector)

Parameters:: a -; b -; nextSelector - first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected.
Returns:

merge

public static LongStream merge(LongIterator a,
                               LongIterator b,
                               LongIterator c,
                               LongBiFunction<MergeResult> nextSelector)

Parameters:: a -; b -; c -; nextSelector - first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected.
Returns:

merge

public static LongStream merge(LongStream a,
                               LongStream b,
                               LongBiFunction<MergeResult> nextSelector)

Parameters:: a -; b -; nextSelector - first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected.
Returns:

merge

public static LongStream merge(LongStream a,
                               LongStream b,
                               LongStream c,
                               LongBiFunction<MergeResult> nextSelector)

Parameters:: a -; b -; c -; nextSelector - first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected.
Returns:

merge

public static LongStream merge(Collection<? extends LongStream> c,
                               LongBiFunction<MergeResult> nextSelector)

Parameters:: c -; nextSelector - first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected.
Returns:

parallelMerge

public static LongStream parallelMerge(Collection<? extends LongStream> c,
                                       LongBiFunction<MergeResult> nextSelector)

Parameters:: c -; nextSelector - first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected.
Returns:

parallelMerge

public static LongStream parallelMerge(Collection<? extends LongStream> c,
                                       LongBiFunction<MergeResult> nextSelector,
                                       int maxThreadNum)

Parameters:: c -; nextSelector - first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected.; maxThreadNum -
Returns:

carry
```
public S carry(C action)
```
Description copied from interface: BaseStream

Same as peek

Specified by:

carry in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

Returns:

See Also:

BaseStream.peek(Object)

sliding
```
public Stream<S> sliding(int windowSize)
```
Specified by:

sliding in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

Returns:

See Also:

BaseStream.sliding(int, int)

slidingToList
```
public Stream<PL> slidingToList(int windowSize)
```
Specified by:

slidingToList in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

Returns:

See Also:

BaseStream.sliding(int, int)

shuffled
```
public S shuffled()
```
Description copied from interface: BaseStream

This method only run sequentially, even in parallel stream and all elements will be loaded to memory.

Specified by:

shuffled in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

Returns:

toImmutableList
```
public ImmutableList<T> toImmutableList()
```
Specified by:

toImmutableList in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

toImmutableSet
```
public ImmutableSet<T> toImmutableSet()
```
Specified by:

toImmutableSet in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

join
```
public String join(CharSequence delimiter)
```
Specified by:

join in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

println
```
public void println()
```
Specified by:

println in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

isParallel
```
public boolean isParallel()
```
Specified by:

isParallel in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

Returns:

sequential
```
public S sequential()
```
Specified by:

sequential in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

Returns:

parallel
```
public S parallel()
```
Specified by:

parallel in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

Returns:

parallel
```
public S parallel(int maxThreadNum)
```
Specified by:

parallel in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

Returns:

parallel
```
public S parallel(BaseStream.Splitor splitor)
```
Specified by:

parallel in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

Returns:

parallel

public S parallel(int maxThreadNum,
                  BaseStream.Splitor splitor)

Description copied from interface: BaseStream

Returns an equivalent stream that is parallel. May return itself if the stream was already parallel with the same maxThreadNum and splitor as the specified ones.

When to use parallel Streams?

First of all, do NOT and should NOT use parallel Streams if you don't have any problem with sequential Streams, because using parallel Streams has extra cost.
Consider using parallel Streams only when N(the number of elements) * Q(cost per element of F, the per-element function (usually a lambda)) is big enough(e.g. IO involved. Network: DB/web service request..., Reading/Writing file...).
It's easy to test out the differences of performance by sequential Streams and parallel Streams with Profiler:

 
 Profiler.run(1, 1, 3, "sequential", () -> Stream.of(list).operation(F)...).printResult();
 Profiler.run(1, 1, 3, "parallel", () -> Stream.of(list).parallel().operation(F)...).printResult();

Here is a sample performance test with computer: CPU Intel i7-3520M 4-cores 2.9 GHz, JDK 1.8.0_101, Windows 7:

 
 public void test_perf() {
     final String[] strs = new String[10_000];
     N.fill(strs, N.uuid());

     final int m = 1;
     final Function mapper = str -> {
         long result = 0;
         for (int i = 0; i < m; i++) {
             result += sum(str.toCharArray()) + 1;
         }
         return result;
     };

     final MutableLong sum = MutableLong.of(0);

     for (int i = 0, len = strs.length; i < len; i++) {
         sum.add(mapper.apply(strs[i]));
     }

     final int threadNum = 1, loopNum = 100, roundNum = 3;

     Profiler.run(threadNum, loopNum, roundNum, "For Loop", () -> {
         long result = 0;
         for (int i = 0, len = strs.length; i < len; i++) {
             result += mapper.apply(strs[i]);
         }
         assertEquals(sum.longValue(), result);
     }).printResult();

     Profiler.run(threadNum, loopNum, roundNum, "JDK Sequential",
             () -> assertEquals(sum.longValue(), java.util.stream.Stream.of(strs).map(mapper).mapToLong(e -> e).sum())).printResult();

     Profiler.run(threadNum, loopNum, roundNum, "JDK Parallel",
             () -> assertEquals(sum.longValue(), java.util.stream.Stream.of(strs).parallel().map(mapper).mapToLong(e -> e).sum())).printResult();

     Profiler.run(threadNum, loopNum, roundNum, "Abcus Sequential",
             () -> assertEquals(sum.longValue(), Stream.of(strs).map(mapper).mapToLong(e -> e).sum().longValue())).printResult();

     Profiler.run(threadNum, loopNum, roundNum, "Abcus Parallel",
             () -> assertEquals(sum.longValue(), Stream.of(strs).parallel().map(mapper).mapToLong(e -> e).sum().longValue())).printResult();
 }

And test result: Unit is milliseconds. N(the number of elements) is 10_000, Q(cost per element of F, the per-element function (usually a lambda), here is mapper) is calculated by: value of 'For loop' / N(10_000).

	m = 1	m = 10	m = 50	m = 100	m = 500	m = 1000
Q	0.00002	0.0002	0.001	0.002	0.01	0.02
For Loop	0.23	2.3	11	22	110	219
JDK Sequential	0.28	2.3	11	22	114	212
JDK Parallel	0.22	1.3	6	12	66	122
Abcus Sequential	0.3	2	11	22	112	212
Abcus Parallel	11	11	11	16	77	128

Comparison:

Again, do NOT and should NOT use parallel Streams if you don't have any performance problem with sequential Streams, because using parallel Streams has extra cost.
Again, consider using parallel Streams only when N(the number of elements) * Q(cost per element of F, the per-element function (usually a lambda)) is big enough.
The implementation of parallel Streams in Abacus is more than 10 times, slower than parallel Streams in JDK when Q is tiny(here is less than 0.0002 milliseconds by the test):

The implementation of parallel Streams in JDK 8 still can beat the sequential/for loop when Q is tiny(Here is 0.00002 milliseconds by the test). That's amazing, considering the extra cost brought by parallel computation. It's well done.
The implementation of parallel Streams in Abacus is pretty simple and straight forward. The extra cost(starting threads/synchronization/queue...) brought by parallel Streams in Abacus is too bigger to tiny Q(Here is less than 0.001 milliseconds by the test). But it starts to be faster than sequential Streams when Q is big enough(Here is 0.001 milliseconds by the test) and starts to catch the parallel Streams in JDK when Q is bigger(Here is 0.01 milliseconds by the test).
Consider using the parallel Streams in Abacus when Q is big enough, specially when IO involved in F. Because one IO operation(e.g. DB/web service request..., Reading/Writing file...) usually takes 1 to 1000 milliseconds, or even longer. By the parallel Streams APIs in Abacus, it's very simple to specify max thread numbers. Sometimes, it's much faster to execute IO/Network requests with a bit more threads. It's fair to say that the parallel Streams in Abacus is high efficient, may same as or faster than the parallel Streams in JDK when Q is big enough, except F is heavy cpu-used operation. Most of the times, the Q is big enough to consider using parallel Stream is because IO/Network is involved in F.

JDK 7 is supported by the Streams in Abacus. It's perfect to work with retrolambda on Android
All primitive types are supported by Stream APIs in Abacus except boolean

A bit more about Lambdas/Stream APIs, you may heard that Lambdas/Stream APIs is 5 time slower than imperative programming. It's true when Q and F is VERY, VERY tiny, like f = (int a, int b) -> a + b;. But if we look into the samples in the article and think about it: it just takes less than 1 milliseconds to get the max value in 100k numbers. There is potential performance issue only if the "get the max value in 100K numbers" call many, many times in your API or single request. Otherwise, the difference between 0.1 milliseconds to 0.5 milliseconds can be totally ignored. Usually we meet performance issue only if Q and F is big enough. However, the performance of Lambdas/Streams APIs is closed to for loop when Q and F is big enough. No matter in which scenario, We don't need and should not concern the performance of Lambdas/Stream APIs.

Although it's is parallel Streams, it doesn't means all the methods are executed in parallel. Because the sequential way is as fast, or even faster than the parallel way for some methods, or is pretty difficult, if not possible, to implement the method by parallel approach. Here are the methods which are executed sequentially even in parallel Streams.

splitXXX/splitAt/splitBy/slidingXXX/collapse, distinct, reverse, rotate, shuffle, indexed, cached, top, kthLargest, count, toArray, toList, toList, toSet, toMultiset, toLongMultiset, intersection(Collection c), difference(Collection c), symmetricDifference(Collection c), forEach(identity, accumulator, predicate), findFirstOrLast, findFirstAndLast

Specified by:

parallel in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

Parameters:

maxThreadNum - Default value is the number of cpu-cores. Steps/operations will be executed sequentially if maxThreadNum is 1.

splitor - The target array is split by ranges for multiple threads if splitor is splitor.ARRAY and target stream composed by array. It looks like:


 for (int i = 0; i < maxThreadNum; i++) {
     final int sliceIndex = i;

     futureList.add(asyncExecutor.execute(new Runnable() {
         public void run() {
             int cursor = fromIndex + sliceIndex * sliceSize;
             final int to = toIndex - cursor > sliceSize ? cursor + sliceSize : toIndex;
             while (cursor < to) {
                 action.accept(elements[cursor++]);
             }
        }
    }));
 }

Otherwise, each thread will get the elements from the target array/iterator in the stream one by one with the target array/iterator synchronized. It looks like:


 for (int i = 0; i < maxThreadNum; i++) {
     futureList.add(asyncExecutor.execute(new Runnable() {
         public void run() {
             T next = null;

             while (true) {
                 synchronized (elements) {
                     if (cursor.intValue() < toIndex) {
                         next = elements[cursor.getAndIncrement()];
                     } else {
                         break;
                     }
                 }

                 action.accept(next);
             }
         }
     }));
 }

Using splitor.ARRAY only when F (the per-element function (usually a lambda)) is very tiny and the cost of synchronization on the target array/iterator is too big to it. For the F involving IO or taking 'long' to complete, choose splitor.ITERATOR. Default value is splitor.ITERATOR.

Returns:

See Also:

MergeResult, com.landawn.abacus.util.Profiler#run(int, int, int, String, Runnable), Understanding Parallel Stream Performance in Java SE 8, When to use parallel Streams

parallel
```
public S parallel(int maxThreadNum,
                  BaseStream.Splitor splitor,
                  Executor executor)
```
Specified by:

parallel in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

executor - should be able to execute maxThreadNum * following up operations in parallel.

Returns:

parallel
```
public S parallel(int maxThreadNum,
                  Executor executor)
```
Specified by:

parallel in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

executor - should be able to execute maxThreadNum * following up operations in parallel.

Returns:

parallel
```
public S parallel(Executor executor)
```
Specified by:

parallel in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

Parameters:

executor - should be able to execute maxThreadNum * following up operations in parallel.

Returns:

close
```
public void close()
```
Specified by:

close in interface BaseStream<T,A,P,C,PL,OT,IT,ITER,S extends com.landawn.abacus.util.stream.StreamBase<T,A,P,C,PL,OT,IT,ITER,S>>

Specified by:

close in interface AutoCloseable

Class LongStream

Nested Class Summary

Nested classes/interfaces inherited from interface com.landawn.abacus.util.stream.BaseStream

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface com.landawn.abacus.util.stream.BaseStream

Method Detail

skipUntil

map

mapToInt

mapToFloat

mapToDouble

mapToObj

flatMap

flattMap

flatMapToInt

flatMapToFloat

flatMapToDouble

flatMapToObj

flattMapToObj

flatMappToObj

rangeMap

rangeMapToObj

collapse

collapse

scan

scan

scan

prepend

append

appendIfEmpty

top

top

toLongList

toMap

toMap

toMap

toMap

toMap

toMap

reduce

reduce

collect

collect

forEach

forEachIndexed

anyMatch

allMatch

noneMatch

findFirst

findLast

findFirstOrLast

findAny

min

max

kthLargest

sum

average

summarize

summarizeAndPercentiles

merge

zipWith

zipWith

zipWith

zipWith

asFloatStream

asDoubleStream

toJdkStream

boxed

iterator

__

empty

of

of

of

of

of

of

of

of