public interface RemoteDoubleStream extends DoubleStream, BaseRemoteStream<Double,DoubleStream>
double
primitive specialization of RemoteStream
.
The following example illustrates an aggregate operation using RemoteStream
and RemoteDoubleStream
, computing the sum of the weights of the red widgets:
double sum = widgets.stream()
.filter(w -> w.getColor() == RED)
.mapToDouble(w -> w.getWeight())
.sum();
This interface is an extension of java.util.stream.DoubleStream
that captures lambdas used as method arguments as serializable lambdas.
RemoteStream
, com.tangosol.util.streamDoubleStream.Builder
Modifier and Type | Method and Description |
---|---|
boolean |
allMatch(DoublePredicate predicate)
Returns whether all elements of this stream match the provided predicate.
|
default boolean |
allMatch(Remote.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.
|
default boolean |
anyMatch(Remote.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. |
RemoteStream<Double> |
boxed()
Returns a
Stream consisting of the elements of this stream, boxed to Double . |
default <R> R |
collect(Remote.Supplier<R> supplier, Remote.ObjDoubleConsumer<R> accumulator, Remote.BiConsumer<R,R> combiner)
Performs a mutable reduction operation on the elements of this stream.
|
<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.
|
RemoteDoubleStream |
filter(DoublePredicate predicate)
Returns a stream consisting of the elements of this stream that match the given predicate.
|
default RemoteDoubleStream |
filter(Remote.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. |
RemoteDoubleStream |
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.
|
default RemoteDoubleStream |
flatMap(Remote.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 action)
Performs an action for each element of this stream.
|
void |
forEachOrdered(DoubleConsumer 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.
|
PrimitiveIterator.OfDouble |
iterator() |
DoubleStream |
limit(long maxSize)
Returns a stream consisting of the elements of this stream, truncated to be no longer than
maxSize in length. |
RemoteDoubleStream |
map(DoubleUnaryOperator mapper)
Returns a stream consisting of the results of applying the given function to the elements of this stream.
|
default RemoteDoubleStream |
map(Remote.DoubleUnaryOperator mapper)
Returns a stream consisting of the results of applying the given function to the elements of this stream.
|
RemoteIntStream |
mapToInt(DoubleToIntFunction mapper)
Returns an
IntStream consisting of the results of applying the given function to the elements of this stream. |
default RemoteIntStream |
mapToInt(Remote.DoubleToIntFunction mapper)
Returns an
IntStream consisting of the results of applying the given function to the elements of this stream. |
RemoteLongStream |
mapToLong(DoubleToLongFunction mapper)
Returns a
LongStream consisting of the results of applying the given function to the elements of this stream. |
default RemoteLongStream |
mapToLong(Remote.DoubleToLongFunction mapper)
Returns a
LongStream consisting of the results of applying the given function to the elements of this stream. |
<U> RemoteStream<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. |
default <U> RemoteStream<U> |
mapToObj(Remote.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.
|
default boolean |
noneMatch(Remote.DoublePredicate predicate)
Returns whether no elements of this stream match the provided predicate.
|
RemoteDoubleStream |
parallel() |
RemoteDoubleStream |
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.
|
default RemoteDoubleStream |
peek(Remote.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.
|
default double |
reduce(double identity, Remote.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.
|
default OptionalDouble |
reduce(Remote.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. |
RemoteDoubleStream |
sequential() |
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() |
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.
|
builder, concat, empty, generate, iterate, of, of
pipeline
close, isParallel, onClose, unordered
RemoteDoubleStream filter(DoublePredicate predicate)
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 includeddefault RemoteDoubleStream filter(Remote.DoublePredicate predicate)
This is an intermediate operation.
predicate
- a non-interfering, stateless predicate to apply to each element to determine if it should be includedRemoteDoubleStream map(DoubleUnaryOperator mapper)
This is an intermediate operation.
map
in interface DoubleStream
mapper
- a non-interfering, stateless function to apply to each elementdefault RemoteDoubleStream map(Remote.DoubleUnaryOperator mapper)
This is an intermediate operation.
mapper
- a non-interfering, stateless function to apply to each element<U> RemoteStream<U> mapToObj(DoubleFunction<? extends U> mapper)
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 elementdefault <U> RemoteStream<U> mapToObj(Remote.DoubleFunction<? extends U> mapper)
Stream
consisting of the results of applying the given function to the elements of this stream.
This is an intermediate operation.
U
- the element type of the new streammapper
- a non-interfering, stateless function to apply to each elementRemoteIntStream mapToInt(DoubleToIntFunction mapper)
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 elementdefault RemoteIntStream mapToInt(Remote.DoubleToIntFunction mapper)
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 elementRemoteLongStream mapToLong(DoubleToLongFunction mapper)
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 elementdefault RemoteLongStream mapToLong(Remote.DoubleToLongFunction mapper)
LongStream
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 elementRemoteDoubleStream flatMap(DoubleFunction<? extends DoubleStream> mapper)
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 valuesRemoteStream.flatMap(Function)
default RemoteDoubleStream flatMap(Remote.DoubleFunction<? extends DoubleStream> mapper)
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 DoubleStream
of new valuesRemoteStream.flatMap(Function)
RemoteDoubleStream peek(DoubleConsumer action)
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 streamdefault RemoteDoubleStream peek(Remote.DoubleConsumer action)
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 streamDoubleStream distinct()
Double.compare(double, double)
.
This is a stateful intermediate operation.
distinct
in interface DoubleStream
DoubleStream sorted()
Double.compare(double, double)
.
This is a stateful intermediate operation.
sorted
in interface DoubleStream
DoubleStream limit(long maxSize)
maxSize
in length.
This is a short-circuiting stateful intermediate operation.
limit
in interface DoubleStream
maxSize
- the number of elements the stream should be limited toIllegalArgumentException
- if maxSize
is negativeDoubleStream skip(long n)
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 skipIllegalArgumentException
- if n
is negativevoid forEach(DoubleConsumer action)
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
action
- a non-interfering action to perform on the elementsvoid forEachOrdered(DoubleConsumer action)
This is a terminal operation.
forEachOrdered
in interface DoubleStream
action
- a non-interfering action to perform on the elementsforEach(DoubleConsumer)
double[] toArray()
This is a terminal operation.
toArray
in interface DoubleStream
double reduce(double identity, DoubleBinaryOperator op)
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.
default double reduce(double identity, Remote.DoubleBinaryOperator op)
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.
OptionalDouble reduce(DoubleBinaryOperator op)
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 valuesreduce(double, DoubleBinaryOperator)
default OptionalDouble reduce(Remote.DoubleBinaryOperator op)
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.
op
- an associative, non-interfering, stateless function for combining two valuesreduce(double, DoubleBinaryOperator)
<R> R collect(Supplier<R> supplier, ObjDoubleConsumer<R> accumulator, BiConsumer<R,R> combiner)
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 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 functionRemoteStream.collect(Supplier, BiConsumer, BiConsumer)
default <R> R collect(Remote.Supplier<R> supplier, Remote.ObjDoubleConsumer<R> accumulator, Remote.BiConsumer<R,R> combiner)
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 reduce(double, DoubleBinaryOperator)
, collect
operations can be parallelized without requiring additional synchronization.
This is a terminal operation.
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 functionRemoteStream.collect(Supplier, BiConsumer, BiConsumer)
double sum()
Summation is a special case of a reduction. If floating-point summation were exact, this method would be equivalent to:
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
OptionalDouble min()
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 emptyOptionalDouble max()
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 emptylong count()
return mapToLong(e -> 1L).sum();
This is a terminal operation.
count
in interface DoubleStream
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.
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 emptyDoubleSummaryStatistics summaryStatistics()
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 streamboolean anyMatch(DoublePredicate predicate)
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
default boolean anyMatch(Remote.DoublePredicate predicate)
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 streamtrue
if any elements of the stream match the provided predicate, otherwise false
boolean allMatch(DoublePredicate predicate)
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
default boolean allMatch(Remote.DoublePredicate predicate)
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 streamtrue
if either all elements of the stream match the provided predicate or the stream is empty, otherwise false
boolean noneMatch(DoublePredicate predicate)
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
default boolean noneMatch(Remote.DoublePredicate predicate)
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 streamtrue
if either no elements of the stream match the provided predicate or the stream is empty, otherwise false
OptionalDouble findFirst()
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 emptyOptionalDouble findAny()
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 findFirst()
instead.)
findAny
in interface DoubleStream
OptionalDouble
describing some element of this stream, or an empty OptionalDouble
if the stream is emptyfindFirst()
RemoteStream<Double> boxed()
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
RemoteDoubleStream sequential()
sequential
in interface BaseStream<Double,DoubleStream>
sequential
in interface DoubleStream
RemoteDoubleStream parallel()
parallel
in interface BaseStream<Double,DoubleStream>
parallel
in interface DoubleStream
PrimitiveIterator.OfDouble iterator()
iterator
in interface BaseStream<Double,DoubleStream>
iterator
in interface DoubleStream
Spliterator.OfDouble spliterator()
spliterator
in interface BaseStream<Double,DoubleStream>
spliterator
in interface DoubleStream