LongStream

allMatch

abstract fun allMatch(predicate: LongPredicate!): Boolean

Returns whether all elements of this stream match the provided predicate. May not evaluate the predicate on all elements if not necessary for determining the result. If the stream is empty then true is returned and the predicate is not evaluated.

This is a short-circuiting terminal operation.

anyMatch

abstract fun anyMatch(predicate: LongPredicate!): Boolean

Returns whether any elements of this stream match the provided predicate. May not evaluate the predicate on all elements if not necessary for determining the result. If the stream is empty then false is returned and the predicate is not evaluated.

This is a short-circuiting terminal operation.

asDoubleStream

abstract fun asDoubleStream(): DoubleStream!

Returns a DoubleStream consisting of the elements of this stream, converted to double.

This is an intermediate operation.

average

abstract fun average(): OptionalDouble!

Returns an OptionalDouble describing the arithmetic mean of elements of this stream, or an empty optional if this stream is empty. This is a special case of a reduction.

This is a terminal operation.

boxed

abstract fun boxed(): Stream<Long!>!

Returns a Stream consisting of the elements of this stream, each boxed to a Long.

This is an intermediate operation.

builder

open static fun builder(): LongStream.Builder!

Returns a builder for a LongStream.

collect

abstract fun <R : Any!> collect(
    supplier: Supplier<R>!, 
    accumulator: ObjLongConsumer<R>!, 
    combiner: BiConsumer<R, R>!
): R

Performs a mutable reduction operation on the elements of this stream. A mutable reduction is one in which the reduced value is a mutable result container, such as an ArrayList, and elements are incorporated by updating the state of the result rather than by replacing the result. This produces a result equivalent to:

<code>R result = supplier.get();
      for (long element : this stream)
          accumulator.accept(result, element);
      return result;
  </code>

Like reduce(long,java.util.function.LongBinaryOperator), collect operations can be parallelized without requiring additional synchronization.

This is a terminal operation.

concat

open static fun concat(
    a: LongStream!, 
    b: LongStream!
): LongStream!

Creates a lazily concatenated stream whose elements are all the elements of the first stream followed by all the elements of the second stream. The resulting stream is ordered if both of the input streams are ordered, and parallel if either of the input streams is parallel. When the resulting stream is closed, the close handlers for both input streams are invoked.

count

abstract fun count(): Long

Returns the count of elements in this stream. This is a special case of a reduction and is equivalent to:

<code>return map(e -&gt; 1L).sum();
  </code>

This is a terminal operation.

distinct

abstract fun distinct(): LongStream!

Returns a stream consisting of the distinct elements of this stream.

This is a stateful intermediate operation.

empty

open static fun empty(): LongStream!

Returns an empty sequential LongStream.

filter

abstract fun filter(predicate: LongPredicate!): LongStream!

Returns a stream consisting of the elements of this stream that match the given predicate.

This is an intermediate operation.

findAny

abstract fun findAny(): OptionalLong!

Returns an OptionalLong describing some element of the stream, or an empty OptionalLong if the stream is empty.

This is a short-circuiting terminal operation.

The behavior of this operation is explicitly nondeterministic; it is free to select any element in the stream. This is to allow for maximal performance in parallel operations; the cost is that multiple invocations on the same source may not return the same result. (If a stable result is desired, use findFirst() instead.)

findFirst

abstract fun findFirst(): OptionalLong!

Returns an OptionalLong describing the first element of this stream, or an empty OptionalLong if the stream is empty. If the stream has no encounter order, then any element may be returned.

This is a short-circuiting terminal operation.

flatMap

abstract fun flatMap(mapper: LongFunction<out LongStream!>!): LongStream!

Returns a stream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)

This is an intermediate operation.

forEach

abstract fun forEach(action: LongConsumer!): Unit

Performs an action for each element of this stream.

This is a terminal operation.

For parallel stream pipelines, this operation does not guarantee to respect the encounter order of the stream, as doing so would sacrifice the benefit of parallelism. For any given element, the action may be performed at whatever time and in whatever thread the library chooses. If the action accesses shared state, it is responsible for providing the required synchronization.

forEachOrdered

abstract fun forEachOrdered(action: LongConsumer!): Unit

Performs an action for each element of this stream, guaranteeing that each element is processed in encounter order for streams that have a defined encounter order.

This is a terminal operation.

generate

open static fun generate(s: LongSupplier!): LongStream!

Returns an infinite sequential unordered stream where each element is generated by the provided LongSupplier. This is suitable for generating constant streams, streams of random elements, etc.

iterate

open static fun iterate(
    seed: Long, 
    f: LongUnaryOperator!
): LongStream!

Returns an infinite sequential ordered LongStream produced by iterative application of a function f to an initial element seed, producing a Stream consisting of seed, f(seed), f(f(seed)), etc.

The first element (position 0) in the LongStream will be the provided seed. For n > 0, the element at position n, will be the result of applying the function f to the element at position n - 1.

iterator

abstract fun iterator(): PrimitiveIterator.OfLong!

limit

abstract fun limit(maxSize: Long): LongStream!

Returns a stream consisting of the elements of this stream, truncated to be no longer than maxSize in length.

This is a short-circuiting stateful intermediate operation.

map

abstract fun map(mapper: LongUnaryOperator!): LongStream!

Returns a stream consisting of the results of applying the given function to the elements of this stream.

This is an intermediate operation.

mapToDouble

abstract fun mapToDouble(mapper: LongToDoubleFunction!): DoubleStream!

Returns a DoubleStream consisting of the results of applying the given function to the elements of this stream.

This is an intermediate operation.

mapToInt

abstract fun mapToInt(mapper: LongToIntFunction!): IntStream!

Returns an IntStream consisting of the results of applying the given function to the elements of this stream.

This is an intermediate operation.

mapToObj

abstract fun <U : Any!> mapToObj(mapper: LongFunction<out U>!): Stream<U>!

Returns an object-valued Stream consisting of the results of applying the given function to the elements of this stream.

This is an intermediate operation.

max

abstract fun max(): OptionalLong!

Returns an OptionalLong describing the maximum element of this stream, or an empty optional if this stream is empty. This is a special case of a reduction and is equivalent to:

<code>return reduce(Long::max);
  </code>

This is a terminal operation.

min

abstract fun min(): OptionalLong!

Returns an OptionalLong describing the minimum element of this stream, or an empty optional if this stream is empty. This is a special case of a reduction and is equivalent to:

<code>return reduce(Long::min);
  </code>

This is a terminal operation.

noneMatch

abstract fun noneMatch(predicate: LongPredicate!): Boolean

Returns whether no elements of this stream match the provided predicate. May not evaluate the predicate on all elements if not necessary for determining the result. If the stream is empty then true is returned and the predicate is not evaluated.

This is a short-circuiting terminal operation.

of

open static fun of(t: Long): LongStream!

Returns a sequential LongStream containing a single element.

of

open static fun of(vararg values: Long): LongStream!

Returns a sequential ordered stream whose elements are the specified values.

parallel

abstract fun parallel(): LongStream!

peek

abstract fun peek(action: LongConsumer!): LongStream!

Returns a stream consisting of the elements of this stream, additionally performing the provided action on each element as elements are consumed from the resulting stream.

This is an intermediate operation.

For parallel stream pipelines, the action may be called at whatever time and in whatever thread the element is made available by the upstream operation. If the action modifies shared state, it is responsible for providing the required synchronization.

range

open static fun range(
    startInclusive: Long, 
    endExclusive: Long
): LongStream!

Returns a sequential ordered LongStream from startInclusive (inclusive) to endExclusive (exclusive) by an incremental step of 1.

rangeClosed

open static fun rangeClosed(
    startInclusive: Long, 
    endInclusive: Long
): LongStream!

Returns a sequential ordered LongStream from startInclusive (inclusive) to endInclusive (inclusive) by an incremental step of 1.

reduce

abstract fun reduce(
    identity: Long, 
    op: LongBinaryOperator!
): Long

Performs a reduction on the elements of this stream, using the provided identity value and an associative accumulation function, and returns the reduced value. This is equivalent to:

<code>long result = identity;
      for (long element : this stream)
          result = accumulator.applyAsLong(result, element)
      return result;
  </code>

The identity value must be an identity for the accumulator function. This means that for all x, accumulator.apply(identity, x) is equal to x. The accumulator function must be an associative function.

This is a terminal operation.

reduce

abstract fun reduce(op: LongBinaryOperator!): OptionalLong!

Performs a reduction on the elements of this stream, using an associative accumulation function, and returns an OptionalLong describing the reduced value, if any. This is equivalent to:

<code>boolean foundAny = false;
      long result = null;
      for (long element : this stream) {
          if (!foundAny) {
              foundAny = true;
              result = element;
          }
          else
              result = accumulator.applyAsLong(result, element);
      }
      return foundAny ? OptionalLong.of(result) : OptionalLong.empty();
  </code>

The accumulator function must be an associative function.

This is a terminal operation.

sequential

abstract fun sequential(): LongStream!

skip

abstract fun skip(n: Long): LongStream!

Returns a stream consisting of the remaining elements of this stream after discarding the first n elements of the stream. If this stream contains fewer than n elements then an empty stream will be returned.

This is a stateful intermediate operation.

sorted

abstract fun sorted(): LongStream!

Returns a stream consisting of the elements of this stream in sorted order.

This is a stateful intermediate operation.

spliterator

abstract fun spliterator(): Spliterator.OfLong!

sum

abstract fun sum(): Long

Returns the sum of elements in this stream. This is a special case of a reduction and is equivalent to:

<code>return reduce(0, Long::sum);
  </code>

This is a terminal operation.

summaryStatistics

abstract fun summaryStatistics(): LongSummaryStatistics!

Returns a LongSummaryStatistics describing various summary data about the elements of this stream. This is a special case of a reduction.

This is a terminal operation.

toArray

abstract fun toArray(): LongArray!

Returns an array containing the elements of this stream.

This is a terminal operation.