jdk.util.stream.LongStream — clojure-interop/java.util.stream 1.0.5

A sequence of primitive long-valued elements supporting sequential and parallel aggregate operations. This is the long primitive specialization of Stream.

The following example illustrates an aggregate operation using Stream and LongStream, computing the sum of the weights of the red widgets:

long sum = widgets.stream()
                  .filter(w -> w.getColor() == RED)
                  .mapToLong(w -> w.getWeight())
                  .sum();

See the class documentation for Stream and the package documentation for java.util.stream for additional specification of streams, stream operations, stream pipelines, and parallelism.

*builder clj

(*builder)

Returns a builder for a LongStream.

returns: a stream builder - java.util.stream.LongStream$Builder

*concat clj

(*concat a b)

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.

a - the first stream - java.util.stream.LongStream b - the second stream - java.util.stream.LongStream

returns: the concatenation of the two input streams - java.util.stream.LongStream

*empty clj

(*empty)

Returns an empty sequential LongStream.

returns: an empty sequential stream - java.util.stream.LongStream

*generate clj

(*generate s)

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.

s - the LongSupplier for generated elements - java.util.function.LongSupplier

returns: a new infinite sequential unordered LongStream - java.util.stream.LongStream

*iterate clj

(*iterate seed f)

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.

seed - the initial element - long f - a function to be applied to to the previous element to produce a new element - java.util.function.LongUnaryOperator

returns: a new sequential LongStream - java.util.stream.LongStream

*of clj

(*of t)

Returns a sequential LongStream containing a single element.

t - the single element - long

returns: a singleton sequential stream - java.util.stream.LongStream

*range clj

(*range start-inclusive end-exclusive)

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

start-inclusive - the (inclusive) initial value - long end-exclusive - the exclusive upper bound - long

returns: a sequential LongStream for the range of long elements - java.util.stream.LongStream

*range-closed clj

(*range-closed start-inclusive end-inclusive)

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

start-inclusive - the (inclusive) initial value - long end-inclusive - the inclusive upper bound - long

returns: a sequential LongStream for the range of long elements - java.util.stream.LongStream

all-match clj

(all-match this predicate)

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.

predicate - a non-interfering, stateless predicate to apply to elements of this stream - java.util.function.LongPredicate

returns: true if either all elements of the stream match the provided predicate or the stream is empty, otherwise false - boolean

any-match clj

(any-match this predicate)

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.

predicate - a non-interfering, stateless predicate to apply to elements of this stream - java.util.function.LongPredicate

returns: true if any elements of the stream match the provided predicate, otherwise false - boolean

as-double-stream clj

(as-double-stream this)

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

This is an intermediate operation.

returns: a DoubleStream consisting of the elements of this stream, converted to double - java.util.stream.DoubleStream

average clj

(average this)

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.

returns: an OptionalDouble containing the average element of this stream, or an empty optional if the stream is empty - java.util.OptionalDouble

boxed clj

(boxed this)

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

This is an intermediate operation.

returns: a Stream consistent of the elements of this stream, each boxed to Long - java.util.stream.Stream<java.lang.Long>

collect clj

(collect this supplier accumulator combiner)

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:

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

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

This is a terminal operation.

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. - java.util.function.Supplier accumulator - an associative, non-interfering, stateless function for incorporating an additional element into a result - java.util.function.ObjLongConsumer combiner - an associative, non-interfering, stateless function for combining two values, which must be compatible with the accumulator function - java.util.function.BiConsumer

returns: the result of the reduction - <R> R

count clj

(count this)

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

 return map(e -> 1L).sum();

This is a terminal operation.

returns: the count of elements in this stream - long

distinct clj

(distinct this)

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

This is a stateful intermediate operation.

returns: the new stream - java.util.stream.LongStream

filter clj

(filter this predicate)

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

This is an intermediate operation.

predicate - a non-interfering, stateless predicate to apply to each element to determine if it should be included - java.util.function.LongPredicate

returns: the new stream - java.util.stream.LongStream

find-any clj

(find-any this)

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.)

returns: an OptionalLong describing some element of this stream, or an empty OptionalLong if the stream is empty - java.util.OptionalLong

find-first clj

(find-first this)

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.

returns: an OptionalLong describing the first element of this stream, or an empty OptionalLong if the stream is empty - java.util.OptionalLong

flat-map clj

(flat-map this mapper)

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.

mapper - a non-interfering, stateless function to apply to each element which produces a LongStream of new values - java.util.function.LongFunction

returns: the new stream - java.util.stream.LongStream

for-each clj

(for-each this action)

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.

action - a non-interfering action to perform on the elements - java.util.function.LongConsumer

for-each-ordered clj

(for-each-ordered this action)

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.

action - a non-interfering action to perform on the elements - java.util.function.LongConsumer

iterator clj

(iterator this)

Description copied from interface: BaseStream

returns: the element iterator for this stream - java.util.PrimitiveIterator$OfLong

limit clj

(limit this max-size)

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.

max-size - the number of elements the stream should be limited to - long

returns: the new stream - java.util.stream.LongStream

throws: java.lang.IllegalArgumentException - if maxSize is negative

map clj

(map this mapper)

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

This is an intermediate operation.

mapper - a non-interfering, stateless function to apply to each element - java.util.function.LongUnaryOperator

returns: the new stream - java.util.stream.LongStream

map-to-double clj

(map-to-double this mapper)

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

This is an intermediate operation.

mapper - a non-interfering, stateless function to apply to each element - java.util.function.LongToDoubleFunction

returns: the new stream - java.util.stream.DoubleStream

map-to-int clj

(map-to-int this mapper)

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

This is an intermediate operation.

mapper - a non-interfering, stateless function to apply to each element - java.util.function.LongToIntFunction

returns: the new stream - java.util.stream.IntStream

map-to-obj clj

(map-to-obj this mapper)

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.

mapper - a non-interfering, stateless function to apply to each element - java.util.function.LongFunction

returns: the new stream - <U> java.util.stream.Stream<U>

max clj

(max this)

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:

 return reduce(Long::max);

This is a terminal operation.

returns: an OptionalLong containing the maximum element of this stream, or an empty OptionalLong if the stream is empty - java.util.OptionalLong

min clj

(min this)

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:

 return reduce(Long::min);

This is a terminal operation.

returns: an OptionalLong containing the minimum element of this stream, or an empty OptionalLong if the stream is empty - java.util.OptionalLong

none-match clj

(none-match this predicate)

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.

predicate - a non-interfering, stateless predicate to apply to elements of this stream - java.util.function.LongPredicate

returns: true if either no elements of the stream match the provided predicate or the stream is empty, otherwise false - boolean

parallel clj

(parallel this)

Description copied from interface: BaseStream

returns: a parallel stream - java.util.stream.LongStream

peek clj

(peek this action)

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.

action - a non-interfering action to perform on the elements as they are consumed from the stream - java.util.function.LongConsumer

returns: the new stream - java.util.stream.LongStream

reduce clj

(reduce this op)

(reduce this identity op)

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:

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

but is not constrained to execute sequentially.

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.

identity - the identity value for the accumulating function - long op - an associative, non-interfering, stateless function for combining two values - java.util.function.LongBinaryOperator

returns: the result of the reduction - long

sequential clj

(sequential this)

Description copied from interface: BaseStream

returns: a sequential stream - java.util.stream.LongStream

skip clj

(skip this n)

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.

n - the number of leading elements to skip - long

returns: the new stream - java.util.stream.LongStream

throws: java.lang.IllegalArgumentException - if n is negative

sorted clj

(sorted this)

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

This is a stateful intermediate operation.

returns: the new stream - java.util.stream.LongStream

spliterator clj

(spliterator this)

Description copied from interface: BaseStream

returns: the element spliterator for this stream - java.util.Spliterator$OfLong

sum clj

(sum this)

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

 return reduce(0, Long::sum);

This is a terminal operation.

returns: the sum of elements in this stream - long

summary-statistics clj

(summary-statistics this)

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.

returns: a LongSummaryStatistics describing various summary data about the elements of this stream - java.util.LongSummaryStatistics

to-array clj

(to-array this)

Returns an array containing the elements of this stream.

This is a terminal operation.

returns: an array containing the elements of this stream - long[]