E_IN
- type of elements in the upstream sourcepublic abstract class DoublePipeline<E_IN> extends AbstractPipeline<E_IN,Double,DoubleStream> implements DoubleStream
double
.Modifier and Type | Class and Description |
---|---|
static class |
DoublePipeline.Head<E_IN>
Source stage of a DoubleStream
|
static class |
DoublePipeline.StatefulOp<E_IN>
Base class for a stateful intermediate stage of a DoubleStream.
|
static class |
DoublePipeline.StatelessOp<E_IN>
Base class for a stateless intermediate stage of a DoubleStream.
|
DoubleStream.Builder
sourceOrOpFlags
Modifier and Type | Method and Description |
---|---|
boolean |
allMatch(DoublePredicate predicate)
Returns whether all elements of this stream match the provided predicate.
|
boolean |
anyMatch(DoublePredicate predicate)
Returns whether any elements of this stream match the provided
predicate.
|
OptionalDouble |
average()
Returns an
OptionalDouble describing the arithmetic
mean of elements of this stream, or an empty optional if this
stream is empty. |
Stream<Double> |
boxed()
Returns a
Stream consisting of the elements of this stream,
boxed to Double . |
<R> R |
collect(Supplier<R> supplier,
ObjDoubleConsumer<R> accumulator,
BiConsumer<R,R> combiner)
Performs a mutable
reduction operation on the elements of this stream.
|
long |
count()
Returns the count of elements in this stream.
|
DoubleStream |
distinct()
Returns a stream consisting of the distinct elements of this stream.
|
<P_IN> Node<Double> |
evaluateToNode(PipelineHelper<Double> helper,
Spliterator<P_IN> spliterator,
boolean flattenTree,
IntFunction<Double[]> generator)
Collect elements output from a pipeline into a Node that holds elements
of this shape.
|
DoubleStream |
filter(DoublePredicate predicate)
Returns a stream consisting of the elements of this stream that match
the given predicate.
|
OptionalDouble |
findAny()
Returns an
OptionalDouble describing some element of the stream,
or an empty OptionalDouble if the stream is empty. |
OptionalDouble |
findFirst()
Returns an
OptionalDouble describing the first element of this
stream, or an empty OptionalDouble if the stream is empty. |
DoubleStream |
flatMap(DoubleFunction<? extends DoubleStream> 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.
|
void |
forEach(DoubleConsumer consumer)
Performs an action for each element of this stream.
|
void |
forEachOrdered(DoubleConsumer consumer)
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.
|
void |
forEachWithCancel(Spliterator<Double> spliterator,
Sink<Double> sink)
Traverse the elements of a spliterator compatible with this stream shape,
pushing those elements into a sink.
|
StreamShape |
getOutputShape()
Get the output shape of the pipeline.
|
PrimitiveIterator.OfDouble |
iterator()
Returns an iterator for the elements of this stream.
|
Spliterator.OfDouble |
lazySpliterator(Supplier<? extends Spliterator<Double>> supplier)
Create a lazy spliterator that wraps and obtains the supplied the
spliterator when a method is invoked on the lazy spliterator.
|
DoubleStream |
limit(long maxSize)
Returns a stream consisting of the elements of this stream, truncated
to be no longer than
maxSize in length. |
Node.Builder<Double> |
makeNodeBuilder(long exactSizeIfKnown,
IntFunction<Double[]> generator)
Make a node builder compatible with this stream shape.
|
DoubleStream |
map(DoubleUnaryOperator mapper)
Returns a stream consisting of the results of applying the given
function to the elements of this stream.
|
IntStream |
mapToInt(DoubleToIntFunction mapper)
Returns an
IntStream consisting of the results of applying the
given function to the elements of this stream. |
LongStream |
mapToLong(DoubleToLongFunction mapper)
Returns a
LongStream consisting of the results of applying the
given function to the elements of this stream. |
<U> Stream<U> |
mapToObj(DoubleFunction<? extends U> mapper)
Returns an object-valued
Stream consisting of the results of
applying the given function to the elements of this stream. |
OptionalDouble |
max()
Returns an
OptionalDouble describing the maximum element of this
stream, or an empty OptionalDouble if this stream is empty. |
OptionalDouble |
min()
Returns an
OptionalDouble describing the minimum element of this
stream, or an empty OptionalDouble if this stream is empty. |
boolean |
noneMatch(DoublePredicate predicate)
Returns whether no elements of this stream match the provided predicate.
|
DoubleStream |
peek(DoubleConsumer 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.
|
OptionalDouble |
reduce(DoubleBinaryOperator op)
Performs a reduction on the
elements of this stream, using an
associative accumulation
function, and returns an
OptionalDouble describing the reduced
value, if any. |
double |
reduce(double identity,
DoubleBinaryOperator 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.
|
DoubleStream |
skip(long n)
Returns a stream consisting of the remaining elements of this stream
after discarding the first
n elements of the stream. |
DoubleStream |
sorted()
Returns a stream consisting of the elements of this stream in sorted
order.
|
Spliterator.OfDouble |
spliterator()
Returns a spliterator for the elements of this stream.
|
double |
sum()
Returns the sum of elements in this stream.
|
DoubleSummaryStatistics |
summaryStatistics()
Returns a
DoubleSummaryStatistics describing various summary data
about the elements of this stream. |
double[] |
toArray()
Returns an array containing the elements of this stream.
|
DoubleStream |
unordered()
Returns an equivalent stream that is
unordered.
|
<P_IN> Spliterator<Double> |
wrap(PipelineHelper<Double> ph,
Supplier<Spliterator<P_IN>> supplier,
boolean isParallel)
Create a spliterator that wraps a source spliterator, compatible with
this stream shape, and operations associated with a
PipelineHelper . |
close, evaluate, evaluateToArrayNode, getStreamAndOpFlags, getStreamFlags, isParallel, onClose, opEvaluateParallel, opEvaluateParallelLazy, opIsStateful, opWrapSink, parallel, sequential, wrapSink
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
builder, concat, empty, generate, iterate, of, of, parallel, sequential
close, isParallel, onClose
public final StreamShape getOutputShape()
AbstractPipeline
getOutputShape
in class AbstractPipeline<E_IN,Double,DoubleStream>
public final <P_IN> Node<Double> evaluateToNode(PipelineHelper<Double> helper, Spliterator<P_IN> spliterator, boolean flattenTree, IntFunction<Double[]> generator)
AbstractPipeline
evaluateToNode
in class AbstractPipeline<E_IN,Double,DoubleStream>
helper
- the pipeline helper describing the pipeline stagesspliterator
- the source spliteratorflattenTree
- true if the returned node should be flattenedgenerator
- the array generatorpublic final <P_IN> Spliterator<Double> wrap(PipelineHelper<Double> ph, Supplier<Spliterator<P_IN>> supplier, boolean isParallel)
AbstractPipeline
PipelineHelper
.wrap
in class AbstractPipeline<E_IN,Double,DoubleStream>
ph
- the pipeline helper describing the pipeline stagessupplier
- the supplier of a spliteratorpublic final Spliterator.OfDouble lazySpliterator(Supplier<? extends Spliterator<Double>> supplier)
AbstractPipeline
lazySpliterator
in class AbstractPipeline<E_IN,Double,DoubleStream>
supplier
- the supplier of a spliteratorpublic final void forEachWithCancel(Spliterator<Double> spliterator, Sink<Double> sink)
AbstractPipeline
forEachWithCancel
in class AbstractPipeline<E_IN,Double,DoubleStream>
spliterator
- the spliterator to pull elements fromsink
- the sink to push elements topublic final Node.Builder<Double> makeNodeBuilder(long exactSizeIfKnown, IntFunction<Double[]> generator)
AbstractPipeline
makeNodeBuilder
in class AbstractPipeline<E_IN,Double,DoubleStream>
exactSizeIfKnown
- if >=0, then a node builder will be
created that has a fixed capacity of at most sizeIfKnown elements. If
< 0, then the node builder has an unfixed capacity. A fixed
capacity node builder will throw exceptions if an element is added after
builder has reached capacity, or is built before the builder has reached
capacity.generator
- the array generator to be used to create instances of a
T[] array. For implementations supporting primitive nodes, this parameter
may be ignored.public final PrimitiveIterator.OfDouble iterator()
BaseStream
This is a terminal operation.
iterator
in interface BaseStream<Double,DoubleStream>
iterator
in interface DoubleStream
public final Spliterator.OfDouble spliterator()
BaseStream
This is a terminal operation.
spliterator
in interface BaseStream<Double,DoubleStream>
spliterator
in interface DoubleStream
spliterator
in class AbstractPipeline<E_IN,Double,DoubleStream>
public final Stream<Double> boxed()
DoubleStream
Stream
consisting of the elements of this stream,
boxed to Double
.
This is an intermediate operation.
boxed
in interface DoubleStream
Stream
consistent of the elements of this stream,
each boxed to a Double
public final DoubleStream map(DoubleUnaryOperator mapper)
DoubleStream
This is an intermediate operation.
map
in interface DoubleStream
mapper
- a non-interfering,
stateless
function to apply to each elementpublic final <U> Stream<U> mapToObj(DoubleFunction<? extends U> mapper)
DoubleStream
Stream
consisting of the results of
applying the given function to the elements of this stream.
This is an intermediate operation.
mapToObj
in interface DoubleStream
U
- the element type of the new streammapper
- a non-interfering,
stateless
function to apply to each elementpublic final IntStream mapToInt(DoubleToIntFunction mapper)
DoubleStream
IntStream
consisting of the results of applying the
given function to the elements of this stream.
This is an intermediate operation.
mapToInt
in interface DoubleStream
mapper
- a non-interfering,
stateless
function to apply to each elementpublic final LongStream mapToLong(DoubleToLongFunction mapper)
DoubleStream
LongStream
consisting of the results of applying the
given function to the elements of this stream.
This is an intermediate operation.
mapToLong
in interface DoubleStream
mapper
- a non-interfering,
stateless
function to apply to each elementpublic final DoubleStream flatMap(DoubleFunction<? extends DoubleStream> mapper)
DoubleStream
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.
flatMap
in interface DoubleStream
mapper
- a non-interfering,
stateless
function to apply to each element which produces a
DoubleStream
of new valuesStream.flatMap(Function)
public DoubleStream unordered()
BaseStream
This is an intermediate operation.
unordered
in interface BaseStream<Double,DoubleStream>
public final DoubleStream filter(DoublePredicate predicate)
DoubleStream
This is an intermediate operation.
filter
in interface DoubleStream
predicate
- a non-interfering,
stateless
predicate to apply to each element to determine if it
should be includedpublic final DoubleStream peek(DoubleConsumer action)
DoubleStream
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.
peek
in interface DoubleStream
action
- a
non-interfering action to perform on the elements as
they are consumed from the streampublic final DoubleStream limit(long maxSize)
DoubleStream
maxSize
in length.
limit
in interface DoubleStream
maxSize
- the number of elements the stream should be limited topublic final DoubleStream skip(long n)
DoubleStream
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.
skip
in interface DoubleStream
n
- the number of leading elements to skippublic final DoubleStream sorted()
DoubleStream
Double.compare(double, double)
.
This is a stateful intermediate operation.
sorted
in interface DoubleStream
public final DoubleStream distinct()
DoubleStream
Double.compare(double, double)
.
This is a stateful intermediate operation.
distinct
in interface DoubleStream
public void forEach(DoubleConsumer consumer)
DoubleStream
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.
forEach
in interface DoubleStream
consumer
- a
non-interfering action to perform on the elementspublic void forEachOrdered(DoubleConsumer consumer)
DoubleStream
This is a terminal operation.
forEachOrdered
in interface DoubleStream
consumer
- a
non-interfering action to perform on the elementsDoubleStream.forEach(DoubleConsumer)
public final double sum()
DoubleStream
return reduce(0, Double::sum);
However, since floating-point summation is not exact, the above
code is not necessarily equivalent to the summation computation
done by this method.
If any stream element is a NaN or the sum is at any point a NaN
then the sum will be NaN.
The value of a floating-point sum is a function both
of the input values as well as the order of addition
operations. The order of addition operations of this method is
intentionally not defined to allow for implementation
flexibility to improve the speed and accuracy of the computed
result.
In particular, this method may be implemented using compensated
summation or other technique to reduce the error bound in the
numerical sum compared to a simple summation of double
values.
This is a terminal operation.
sum
in interface DoubleStream
public final OptionalDouble min()
DoubleStream
OptionalDouble
describing the minimum element of this
stream, or an empty OptionalDouble if this stream is empty. The minimum
element will be Double.NaN
if any stream element was NaN. Unlike
the numerical comparison operators, this method considers negative zero
to be strictly smaller than positive zero. This is a special case of a
reduction and is
equivalent to:
return reduce(Double::min);
This is a terminal operation.
min
in interface DoubleStream
OptionalDouble
containing the minimum element of this
stream, or an empty optional if the stream is emptypublic final OptionalDouble max()
DoubleStream
OptionalDouble
describing the maximum element of this
stream, or an empty OptionalDouble if this stream is empty. The maximum
element will be Double.NaN
if any stream element was NaN. Unlike
the numerical comparison operators, this method considers negative zero
to be strictly smaller than positive zero. This is a
special case of a
reduction and is
equivalent to:
return reduce(Double::max);
This is a terminal operation.
max
in interface DoubleStream
OptionalDouble
containing the maximum element of this
stream, or an empty optional if the stream is emptypublic final OptionalDouble average()
OptionalDouble
describing the arithmetic
mean of elements of this stream, or an empty optional if this
stream is empty.
If any recorded value is a NaN or the sum is at any point a NaN
then the average will be NaN.
The average returned can vary depending upon the order in
which values are recorded.
This method may be implemented using compensated summation or
other technique to reduce the error bound in the numerical sum
used to compute the average.
The average is a special case of a reduction.
This is a terminal operation.
average
in interface DoubleStream
OptionalDouble
containing the average element of this
stream, or an empty optional if the stream is emptypublic final long count()
DoubleStream
return mapToLong(e -> 1L).sum();
This is a terminal operation.
count
in interface DoubleStream
public final DoubleSummaryStatistics summaryStatistics()
DoubleStream
DoubleSummaryStatistics
describing various summary data
about the elements of this stream. This is a special
case of a reduction.
This is a terminal operation.
summaryStatistics
in interface DoubleStream
DoubleSummaryStatistics
describing various summary data
about the elements of this streampublic final double reduce(double identity, DoubleBinaryOperator op)
DoubleStream
double result = identity;
for (double element : this stream)
result = accumulator.applyAsDouble(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.
reduce
in interface DoubleStream
identity
- the identity value for the accumulating functionop
- an associative,
non-interfering,
stateless
function for combining two valuesDoubleStream.sum()
,
DoubleStream.min()
,
DoubleStream.max()
,
DoubleStream.average()
public final OptionalDouble reduce(DoubleBinaryOperator op)
DoubleStream
OptionalDouble
describing the reduced
value, if any. This is equivalent to:
boolean foundAny = false;
double result = null;
for (double element : this stream) {
if (!foundAny) {
foundAny = true;
result = element;
}
else
result = accumulator.applyAsDouble(result, element);
}
return foundAny ? OptionalDouble.of(result) : OptionalDouble.empty();
but is not constrained to execute sequentially.
The accumulator
function must be an
associative function.
This is a terminal operation.
reduce
in interface DoubleStream
op
- an associative,
non-interfering,
stateless
function for combining two valuesDoubleStream.reduce(double, DoubleBinaryOperator)
public final <R> R collect(Supplier<R> supplier, ObjDoubleConsumer<R> accumulator, BiConsumer<R,R> combiner)
DoubleStream
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 (double element : this stream)
accumulator.accept(result, element);
return result;
Like DoubleStream.reduce(double, DoubleBinaryOperator)
, collect
operations can be parallelized without requiring additional
synchronization.
This is a terminal operation.
collect
in interface DoubleStream
R
- type of the resultsupplier
- 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.accumulator
- an associative,
non-interfering,
stateless
function for incorporating an additional element into a resultcombiner
- an associative,
non-interfering,
stateless
function for combining two values, which must be
compatible with the accumulator functionStream.collect(Supplier, BiConsumer, BiConsumer)
public final boolean anyMatch(DoublePredicate predicate)
DoubleStream
false
is returned and the predicate is not evaluated.
This is a short-circuiting terminal operation.
anyMatch
in interface DoubleStream
predicate
- a non-interfering,
stateless
predicate to apply to elements of this streamtrue
if any elements of the stream match the provided
predicate, otherwise false
public final boolean allMatch(DoublePredicate predicate)
DoubleStream
true
is
returned and the predicate is not evaluated.
This is a short-circuiting terminal operation.
allMatch
in interface DoubleStream
predicate
- a non-interfering,
stateless
predicate to apply to elements of this streamtrue
if either all elements of the stream match the
provided predicate or the stream is empty, otherwise false
public final boolean noneMatch(DoublePredicate predicate)
DoubleStream
true
is
returned and the predicate is not evaluated.
This is a short-circuiting terminal operation.
noneMatch
in interface DoubleStream
predicate
- a non-interfering,
stateless
predicate to apply to elements of this streamtrue
if either no elements of the stream match the
provided predicate or the stream is empty, otherwise false
public final OptionalDouble findFirst()
DoubleStream
OptionalDouble
describing the first element of this
stream, or an empty OptionalDouble
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.
findFirst
in interface DoubleStream
OptionalDouble
describing the first element of this
stream, or an empty OptionalDouble
if the stream is emptypublic final OptionalDouble findAny()
DoubleStream
OptionalDouble
describing some element of the stream,
or an empty OptionalDouble
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 DoubleStream.findFirst()
instead.)
findAny
in interface DoubleStream
OptionalDouble
describing some element of this stream,
or an empty OptionalDouble
if the stream is emptyDoubleStream.findFirst()
public final double[] toArray()
DoubleStream
This is a terminal operation.
toArray
in interface DoubleStream