Class DoubleStreamEx
- All Implemented Interfaces:
AutoCloseable
,BaseStream<Double,
,DoubleStream> DoubleStream
DoubleStream
implementation with additional functionality-
Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic interface
A helper interface to build a new stream by emitting elements and creating new emitters in a chain.Nested classes/interfaces inherited from interface java.util.stream.DoubleStream
DoubleStream.Builder, DoubleStream.DoubleMapMultiConsumer
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Field Summary
Fields inherited from class one.util.streamex.BaseStreamEx
CONSUMED_MESSAGE, context, spliterator
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Constructor Summary
ConstructorsConstructorDescriptionDoubleStreamEx
(Spliterator.OfDouble spliterator, StreamContext context) DoubleStreamEx
(DoubleStream stream, StreamContext context) -
Method Summary
Modifier and TypeMethodDescriptionboolean
allMatch
(DoublePredicate predicate) boolean
anyMatch
(DoublePredicate predicate) append
(double... values) Returns a newDoubleStreamEx
which is a concatenation of this stream and the stream containing supplied valuesappend
(DoubleStream other) Creates a lazily concatenated stream whose elements are all the elements of this stream followed by all the elements of the other stream.atLeast
(double value) Returns a stream consisting of the elements of this stream that greater than or equal to the specified value.atMost
(double value) Returns a stream consisting of the elements of this stream that less than or equal to the specified value.average()
boxed()
<U> U
chain
(Function<? super DoubleStreamEx, U> mapper) Applies the supplied function to this stream and returns the result of the function.<R> R
collect
(Supplier<R> supplier, ObjDoubleConsumer<R> accumulator, BiConsumer<R, R> combiner) <A,
R> R collect
(DoubleCollector<A, R> collector) Performs a mutable reduction operation on the elements of this stream using anDoubleCollector
which encapsulates the supplier, accumulator and merger functions making easier to reuse collection strategies.static DoubleStreamEx
constant
(double value, long length) Returns a sequential unorderedDoubleStreamEx
of given length which elements are equal to supplied value.long
count()
long
count
(DoublePredicate predicate) Counts the number of elements in the stream that satisfy the predicate.(package private) DoubleStream
(package private) DoubleStreamEx
delegate
(Spliterator.OfDouble spliterator) distinct()
dropWhile
(DoublePredicate predicate) Returns a stream consisting of all elements from this stream starting from the first element which does not match the given predicate.static DoubleStreamEx
empty()
Returns an empty sequentialDoubleStreamEx
.filter
(DoublePredicate predicate) findAny()
findAny
(DoublePredicate predicate) Returns anOptionalDouble
describing some element of the stream, which matches given predicate, or an emptyOptionalDouble
if there's no matching element.findFirst
(DoublePredicate predicate) Returns anOptionalDouble
describing the first element of this stream, which matches given predicate, or an emptyOptionalDouble
if there's no matching element.flatMap
(DoubleFunction<? extends DoubleStream> mapper) flatMapToInt
(DoubleFunction<? extends IntStream> mapper) Returns anIntStreamEx
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.flatMapToLong
(DoubleFunction<? extends LongStream> mapper) Returns aLongStreamEx
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.<R> StreamEx<R>
flatMapToObj
(DoubleFunction<? extends Stream<R>> mapper) Returns aStreamEx
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.double
foldLeft
(double seed, DoubleBinaryOperator accumulator) Folds the elements of this stream using the provided seed object and accumulation function, going left to right.foldLeft
(DoubleBinaryOperator accumulator) Folds the elements of this stream using the provided accumulation function, going left to right.void
forEach
(DoubleConsumer action) void
forEachOrdered
(DoubleConsumer action) static DoubleStreamEx
Returns an infinite sequential unordered stream where each element is generated by the providedDoubleSupplier
.greater
(double value) Returns a stream consisting of the elements of this stream that strictly greater than the specified value.indexOf
(DoublePredicate predicate) Returns anOptionalLong
describing the zero-based index of the first element of this stream, which matches given predicate, or an emptyOptionalLong
if there's no matching element.intersperse
(int delimiter) Returns a new stream containing all the elements of the original stream interspersed with given delimiter.static DoubleStreamEx
iterate
(double seed, DoublePredicate predicate, DoubleUnaryOperator f) Returns a sequential orderedDoubleStreamEx
produced by iterative application of a function to an initial element, conditioned on satisfying the supplied predicate.static DoubleStreamEx
iterate
(double seed, DoubleUnaryOperator f) Returns an infinite sequential orderedDoubleStreamEx
produced by iterative application of a functionf
to an initial elementseed
, producing a stream consisting ofseed
,f(seed)
,f(f(seed))
, etc.iterator()
joining
(CharSequence delimiter) Returns aString
which is the concatenation of the results of callingString.valueOf(double)
on each element of this stream, separated by the specified delimiter, in encounter order.joining
(CharSequence delimiter, CharSequence prefix, CharSequence suffix) Returns aString
which is the concatenation of the results of callingString.valueOf(double)
on each element of this stream, separated by the specified delimiter, with the specified prefix and suffix in encounter order.less
(double value) Returns a stream consisting of the elements of this stream that strictly less than the specified value.limit
(long maxSize) map
(DoubleUnaryOperator mapper) mapFirst
(DoubleUnaryOperator mapper) Returns a stream where the first element is the replaced with the result of applying the given function while the other elements are left intact.mapLast
(DoubleUnaryOperator mapper) Returns a stream where the last element is the replaced with the result of applying the given function while the other elements are left intact.<K,
V> EntryStream<K, V> mapToEntry
(DoubleFunction<? extends K> keyMapper, DoubleFunction<? extends V> valueMapper) Returns anEntryStream
consisting of theMap.Entry
objects which keys and values are results of applying the given functions to the elements of this stream.mapToInt
(DoubleToIntFunction mapper) mapToLong
(DoubleToLongFunction mapper) <U> StreamEx<U>
mapToObj
(DoubleFunction<? extends U> mapper) max()
max
(Comparator<Double> comparator) Returns the maximum element of this stream according to the providedComparator
.<V extends Comparable<? super V>>
OptionalDoublemaxBy
(DoubleFunction<V> keyExtractor) Returns the maximum element of this stream according to the provided key extractor function.maxByDouble
(DoubleUnaryOperator keyExtractor) Returns the maximum element of this stream according to the provided key extractor function.maxByInt
(DoubleToIntFunction keyExtractor) Returns the maximum element of this stream according to the provided key extractor function.maxByLong
(DoubleToLongFunction keyExtractor) Returns the maximum element of this stream according to the provided key extractor function.min()
min
(Comparator<Double> comparator) Returns the minimum element of this stream according to the providedComparator
.<V extends Comparable<? super V>>
OptionalDoubleminBy
(DoubleFunction<V> keyExtractor) Returns the minimum element of this stream according to the provided key extractor function.minByDouble
(DoubleUnaryOperator keyExtractor) Returns the minimum element of this stream according to the provided key extractor function.minByInt
(DoubleToIntFunction keyExtractor) Returns the minimum element of this stream according to the provided key extractor function.minByLong
(DoubleToLongFunction keyExtractor) Returns the minimum element of this stream according to the provided key extractor function.boolean
noneMatch
(DoublePredicate predicate) static DoubleStreamEx
of
(double element) Returns a sequentialDoubleStreamEx
containing a single element.static DoubleStreamEx
of
(double... elements) Returns a sequential orderedDoubleStreamEx
whose elements are the specified values.static DoubleStreamEx
of
(double[] array, int startInclusive, int endExclusive) Returns a sequentialDoubleStreamEx
with the specified range of the specified array as its source.static DoubleStreamEx
of
(float... elements) Returns a sequential orderedDoubleStreamEx
whose elements are the specified float values casted to double.static DoubleStreamEx
of
(float[] array, int startInclusive, int endExclusive) Returns a sequentialDoubleStreamEx
with the specified range of the specified array as its source.static DoubleStreamEx
Returns a sequential orderedDoubleStreamEx
whose elements are the unboxed elements of supplied array.static DoubleStreamEx
of
(DoubleBuffer buf) Returns a sequential orderedDoubleStreamEx
whose elements are the values in the suppliedDoubleBuffer
.static DoubleStreamEx
of
(Collection<Double> collection) Returns a sequential orderedDoubleStreamEx
whose elements are the unboxed elements of supplied collection.static DoubleStreamEx
of
(OptionalDouble optional) Returns a sequentialDoubleStreamEx
containing anOptionalDouble
value, if present, otherwise returns an emptyDoubleStreamEx
.static DoubleStreamEx
of
(PrimitiveIterator.OfDouble iterator) Returns a sequential, orderedDoubleStreamEx
created from givenPrimitiveIterator.OfDouble
.static DoubleStreamEx
Returns an effectively unlimited stream of pseudorandomdouble
values, each between zero (inclusive) and one (exclusive) produced by givenRandom
object.static DoubleStreamEx
Returns an effectively unlimited stream of pseudorandomdouble
values, each conforming to the given origin (inclusive) and bound (exclusive) produced by givenRandom
object.static DoubleStreamEx
Returns a stream producing the givenstreamSize
number of pseudorandomdouble
values, each between zero (inclusive) and one (exclusive) produced by givenRandom
object.static DoubleStreamEx
Returns a stream producing the givenstreamSize
number of pseudorandomdouble
values, each conforming to the given origin (inclusive) and bound (exclusive) produced by givenRandom
object.static DoubleStreamEx
of
(Spliterator.OfDouble spliterator) Returns a sequentialDoubleStreamEx
created from givenSpliterator.OfDouble
.static DoubleStreamEx
of
(DoubleStream stream) Returns aDoubleStreamEx
object which wraps givenDoubleStream
.pairMap
(DoubleBinaryOperator mapper) Returns a stream consisting of the results of applying the given function to the every adjacent pair of elements of this stream.parallel()
parallel
(ForkJoinPool fjp) Returns an equivalent stream that is parallel and bound to the suppliedForkJoinPool
.peek
(DoubleConsumer action) peekFirst
(DoubleConsumer action) Returns a stream consisting of the elements of this stream, additionally performing the provided action on the first stream element when it's consumed from the resulting stream.peekLast
(DoubleConsumer action) Returns a stream consisting of the elements of this stream, additionally performing the provided action on the last stream element when it's consumed from the resulting stream.Returns a stream containing cumulative results of applying the accumulation function going left to right.prepend
(double... values) Returns a newDoubleStreamEx
which is a concatenation of the stream containing supplied values and this streamprepend
(DoubleStream other) Creates a lazily concatenated stream whose elements are all the elements of the other stream followed by all the elements of this stream.static DoubleStreamEx
produce
(Predicate<DoubleConsumer> producer) Return an ordered stream produced by consecutive calls of the supplied producer until it returns false.double
reduce
(double identity, DoubleBinaryOperator op) remove
(DoublePredicate predicate) Returns a stream consisting of the elements of this stream that don't match the given predicate.Returns a stream consisting of the elements of this stream in reverse sorted order.double[]
scanLeft
(double seed, DoubleBinaryOperator accumulator) Produces an array containing cumulative results of applying the accumulation function going left to right using given seed value.double[]
scanLeft
(DoubleBinaryOperator accumulator) Produces an array containing cumulative results of applying the accumulation function going left to right.private static DoubleStreamEx
seq
(DoubleStream stream) skip
(long n) sorted()
sorted
(Comparator<Double> comparator) Returns a stream consisting of the elements of this stream sorted according to the given comparator.<V extends Comparable<? super V>>
DoubleStreamExsortedBy
(DoubleFunction<V> keyExtractor) Returns a stream consisting of the elements of this stream, sorted according to the natural order of the keys extracted by provided function.sortedByDouble
(DoubleUnaryOperator keyExtractor) Returns a stream consisting of the elements of this stream, sorted according to the double values extracted by provided function.sortedByInt
(DoubleToIntFunction keyExtractor) Returns a stream consisting of the elements of this stream, sorted according to the int values extracted by provided function.sortedByLong
(DoubleToLongFunction keyExtractor) Returns a stream consisting of the elements of this stream, sorted according to the long values extracted by provided function.double
sum()
takeWhile
(DoublePredicate predicate) Returns a stream consisting of all elements from this stream until the first element which does not match the given predicate is found.takeWhileInclusive
(DoublePredicate predicate) Returns a stream consisting of all elements from this stream until the first element which does not match the given predicate is found (including the first mismatching element).double[]
toArray()
float[]
Returns afloat[]
array containing the elements of this stream which are converted to floats using(float)
cast operation.static DoubleStreamEx
zip
(double[] first, double[] second, DoubleBinaryOperator mapper) Returns a sequentialDoubleStreamEx
containing the results of applying the given function to the corresponding pairs of values in given two arrays.Methods inherited from class one.util.streamex.BaseStreamEx
close, isParallel, spliterator, stream
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface java.util.stream.BaseStream
close, isParallel
Methods inherited from interface java.util.stream.DoubleStream
mapMulti, spliterator
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Constructor Details
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DoubleStreamEx
DoubleStreamEx(DoubleStream stream, StreamContext context) -
DoubleStreamEx
DoubleStreamEx(Spliterator.OfDouble spliterator, StreamContext context)
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Method Details
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createStream
DoubleStream createStream()- Specified by:
createStream
in classBaseStreamEx<Double,
DoubleStream, Spliterator.OfDouble, DoubleStreamEx>
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seq
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delegate
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unordered
- Specified by:
unordered
in interfaceBaseStream<Double,
DoubleStream> - Overrides:
unordered
in classBaseStreamEx<Double,
DoubleStream, Spliterator.OfDouble, DoubleStreamEx>
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onClose
- Specified by:
onClose
in interfaceBaseStream<Double,
DoubleStream> - Overrides:
onClose
in classBaseStreamEx<Double,
DoubleStream, Spliterator.OfDouble, DoubleStreamEx>
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filter
- Specified by:
filter
in interfaceDoubleStream
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remove
Returns a stream consisting of the elements of this stream that don't match the given predicate.This is an intermediate operation.
- Parameters:
predicate
- a non-interfering, stateless predicate to apply to each element to determine if it should be excluded- Returns:
- the new stream
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greater
Returns a stream consisting of the elements of this stream that strictly greater than the specified value.This is an intermediate operation.
- Parameters:
value
- a value to compare to- Returns:
- the new stream
- Since:
- 0.2.3
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less
Returns a stream consisting of the elements of this stream that strictly less than the specified value.This is an intermediate operation.
- Parameters:
value
- a value to compare to- Returns:
- the new stream
- Since:
- 0.2.3
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atLeast
Returns a stream consisting of the elements of this stream that greater than or equal to the specified value.This is an intermediate operation.
- Parameters:
value
- a value to compare to- Returns:
- the new stream
- Since:
- 0.2.3
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atMost
Returns a stream consisting of the elements of this stream that less than or equal to the specified value.This is an intermediate operation.
- Parameters:
value
- a value to compare to- Returns:
- the new stream
- Since:
- 0.2.3
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map
- Specified by:
map
in interfaceDoubleStream
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mapFirst
Returns a stream where the first element is the replaced with the result of applying the given function while the other elements are left intact.This is a quasi-intermediate operation.
- Parameters:
mapper
- a non-interfering , stateless function to apply to the first element- Returns:
- the new stream
- Since:
- 0.4.1
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mapLast
Returns a stream where the last element is the replaced with the result of applying the given function while the other elements are left intact.This is a quasi-intermediate operation.
The mapper function is called at most once. It could be not called at all if the stream is empty or there is short-circuiting operation downstream.
- Parameters:
mapper
- a non-interfering , stateless function to apply to the last element- Returns:
- the new stream
- Since:
- 0.4.1
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mapToObj
- Specified by:
mapToObj
in interfaceDoubleStream
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mapToInt
- Specified by:
mapToInt
in interfaceDoubleStream
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mapToLong
- Specified by:
mapToLong
in interfaceDoubleStream
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mapToEntry
public <K,V> EntryStream<K,V> mapToEntry(DoubleFunction<? extends K> keyMapper, DoubleFunction<? extends V> valueMapper) Returns anEntryStream
consisting of theMap.Entry
objects which keys and values are results of applying the given functions to the elements of this stream.This is an intermediate operation.
- Type Parameters:
K
- TheEntry
key typeV
- TheEntry
value type- Parameters:
keyMapper
- a non-interfering, stateless function to apply to each elementvalueMapper
- a non-interfering, stateless function to apply to each element- Returns:
- the new stream
- Since:
- 0.3.1
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flatMap
- Specified by:
flatMap
in interfaceDoubleStream
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flatMapToInt
Returns anIntStreamEx
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 isnull
an empty stream is used, instead.)This is an intermediate operation.
- Parameters:
mapper
- a non-interfering, stateless function to apply to each element which produces anIntStream
of new values- Returns:
- the new stream
- Since:
- 0.3.0
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flatMapToLong
Returns aLongStreamEx
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 isnull
an empty stream is used, instead.)This is an intermediate operation.
- Parameters:
mapper
- a non-interfering, stateless function to apply to each element which produces aLongStream
of new values- Returns:
- the new stream
- Since:
- 0.3.0
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flatMapToObj
Returns aStreamEx
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 isnull
an empty stream is used, instead.)This is an intermediate operation.
- Type Parameters:
R
- The element type of the new stream- Parameters:
mapper
- a non-interfering, stateless function to apply to each element which produces aStream
of new values- Returns:
- the new stream
- Since:
- 0.3.0
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intersperse
Returns a new stream containing all the elements of the original stream interspersed with given delimiter.For example,
DoubleStreamEx.of(1, 2, 3).intersperse(4)
will yield a stream containing five elements: 1, 4, 2, 4, 3.This is an intermediate operation.
- Parameters:
delimiter
- a delimiter to be inserted between each pair of elements- Returns:
- the new stream
- Since:
- 0.6.6
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distinct
- Specified by:
distinct
in interfaceDoubleStream
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sorted
- Specified by:
sorted
in interfaceDoubleStream
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sorted
Returns a stream consisting of the elements of this stream sorted according to the given comparator. Stream elements are boxed before passing to the comparator.For ordered streams, the sort is stable. For unordered streams, no stability guarantees are made.
This is a stateful intermediate operation.
- Parameters:
comparator
- a non-interfering , statelessComparator
to be used to compare stream elements- Returns:
- the new stream
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reverseSorted
Returns a stream consisting of the elements of this stream in reverse sorted order. The elements are compared for equality according toDouble.compare(double, double)
.This is a stateful intermediate operation.
- Returns:
- the new stream
- Since:
- 0.0.8
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sortedBy
Returns a stream consisting of the elements of this stream, sorted according to the natural order of the keys extracted by provided function.For ordered streams, the sort is stable. For unordered streams, no stability guarantees are made.
This is a stateful intermediate operation.
- Type Parameters:
V
- the type of theComparable
sort key- Parameters:
keyExtractor
- a non-interfering , stateless function to be used to extract sorting keys- Returns:
- the new stream
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sortedByInt
Returns a stream consisting of the elements of this stream, sorted according to the int values extracted by provided function.For ordered streams, the sort is stable. For unordered streams, no stability guarantees are made.
This is a stateful intermediate operation.
- Parameters:
keyExtractor
- a non-interfering , stateless function to be used to extract sorting keys- Returns:
- the new stream
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sortedByLong
Returns a stream consisting of the elements of this stream, sorted according to the long values extracted by provided function.For ordered streams, the sort is stable. For unordered streams, no stability guarantees are made.
This is a stateful intermediate operation.
- Parameters:
keyExtractor
- a non-interfering , stateless function to be used to extract sorting keys- Returns:
- the new stream
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sortedByDouble
Returns a stream consisting of the elements of this stream, sorted according to the double values extracted by provided function.For ordered streams, the sort is stable. For unordered streams, no stability guarantees are made.
This is a stateful intermediate operation.
- Parameters:
keyExtractor
- a non-interfering , stateless function to be used to extract sorting keys- Returns:
- the new stream
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peek
- Specified by:
peek
in interfaceDoubleStream
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peekFirst
Returns a stream consisting of the elements of this stream, additionally performing the provided action on the first stream element when it's consumed from the resulting stream.This is an intermediate operation.
The action is called at most once. For parallel stream pipelines, it's not guaranteed in which thread it will be executed, so if it modifies shared state, it is responsible for providing the required synchronization.
Note that the action might not be called at all if the first element is not consumed from the input (for example, if there's short-circuiting operation downstream which stopped the stream before the first element).
This method exists mainly to support debugging.
- Parameters:
action
- a non-interfering action to perform on the first stream element as it is consumed from the stream- Returns:
- the new stream
- Since:
- 0.6.0
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peekLast
Returns a stream consisting of the elements of this stream, additionally performing the provided action on the last stream element when it's consumed from the resulting stream.This is an intermediate operation.
The action is called at most once. For parallel stream pipelines, it's not guaranteed in which thread it will be executed, so if it modifies shared state, it is responsible for providing the required synchronization.
Note that the action might not be called at all if the last element is not consumed from the input (for example, if there's short-circuiting operation downstream).
This method exists mainly to support debugging.
- Parameters:
action
- a non-interfering action to perform on the first stream element as it is consumed from the stream- Returns:
- the new stream
- Since:
- 0.6.0
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limit
- Specified by:
limit
in interfaceDoubleStream
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skip
- Specified by:
skip
in interfaceDoubleStream
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forEach
- Specified by:
forEach
in interfaceDoubleStream
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forEachOrdered
- Specified by:
forEachOrdered
in interfaceDoubleStream
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toArray
public double[] toArray()- Specified by:
toArray
in interfaceDoubleStream
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toFloatArray
public float[] toFloatArray()Returns afloat[]
array containing the elements of this stream which are converted to floats using(float)
cast operation.This is a terminal operation.
- Returns:
- an array containing the elements of this stream
- Since:
- 0.3.0
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reduce
- Specified by:
reduce
in interfaceDoubleStream
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reduce
- Specified by:
reduce
in interfaceDoubleStream
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foldLeft
Folds the elements of this stream using the provided accumulation function, going left to right. This is equivalent to:boolean foundAny = false; double result = 0; for (double element : this stream) { if (!foundAny) { foundAny = true; result = element; } else result = accumulator.apply(result, element); } return foundAny ? OptionalDouble.of(result) : OptionalDouble.empty();
This is a terminal operation.
This method cannot take all the advantages of parallel streams as it must process elements strictly left to right. If your accumulator function is associative, consider using
reduce(DoubleBinaryOperator)
method.For parallel stream it's not guaranteed that accumulator will always be executed in the same thread.
- Parameters:
accumulator
- a non-interfering , stateless function for incorporating an additional element into a result- Returns:
- the result of the folding
- Since:
- 0.4.0
- See Also:
-
foldLeft
Folds the elements of this stream using the provided seed object and accumulation function, going left to right. This is equivalent to:double result = identity; for (double element : this stream) result = accumulator.apply(result, element) return result;
This is a terminal operation.
This method cannot take all the advantages of parallel streams as it must process elements strictly left to right. If your accumulator function is associative, consider using
reduce(double, DoubleBinaryOperator)
method.For parallel stream it's not guaranteed that accumulator will always be executed in the same thread.
- Parameters:
seed
- the starting valueaccumulator
- a non-interfering , stateless function for incorporating an additional element into a result- Returns:
- the result of the folding
- Since:
- 0.4.0
- See Also:
-
scanLeft
Produces an array containing cumulative results of applying the accumulation function going left to right.This is a terminal operation.
For parallel stream it's not guaranteed that accumulator will always be executed in the same thread.
This method cannot take all the advantages of parallel streams as it must process elements strictly left to right.
- Parameters:
accumulator
- a non-interfering , stateless function for incorporating an additional element into a result- Returns:
- the array where the first element is the first element of this stream and every successor element is the result of applying accumulator function to the previous array element and the corresponding stream element. The resulting array has the same length as this stream.
- Since:
- 0.5.1
- See Also:
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scanLeft
Produces an array containing cumulative results of applying the accumulation function going left to right using given seed value.This is a terminal operation.
For parallel stream it's not guaranteed that accumulator will always be executed in the same thread.
This method cannot take all the advantages of parallel streams as it must process elements strictly left to right.
- Parameters:
seed
- the starting valueaccumulator
- a non-interfering , stateless function for incorporating an additional element into a result- Returns:
- the array where the first element is the seed and every successor element is the result of applying accumulator function to the previous array element and the corresponding stream element. The resulting array is one element longer than this stream.
- Since:
- 0.5.1
- See Also:
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collect
public <R> R collect(Supplier<R> supplier, ObjDoubleConsumer<R> accumulator, BiConsumer<R, R> combiner) - Specified by:
collect
in interfaceDoubleStream
- See Also:
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collect
Performs a mutable reduction operation on the elements of this stream using anDoubleCollector
which encapsulates the supplier, accumulator and merger functions making easier to reuse collection strategies.Like
reduce(double, DoubleBinaryOperator)
,collect
operations can be parallelized without requiring additional synchronization.This is a terminal operation.
- Type Parameters:
A
- the intermediate accumulation type of theDoubleCollector
R
- type of the result- Parameters:
collector
- theDoubleCollector
describing the reduction- Returns:
- the result of the reduction
- Since:
- 0.3.0
- See Also:
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sum
public double sum()- Specified by:
sum
in interfaceDoubleStream
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min
- Specified by:
min
in interfaceDoubleStream
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min
Returns the minimum element of this stream according to the providedComparator
.This is a terminal operation.
- Parameters:
comparator
- a non-interfering, statelessComparator
to compare elements of this stream- Returns:
- an
OptionalDouble
describing the minimum element of this stream, or an emptyOptionalDouble
if the stream is empty - Since:
- 0.1.2
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minBy
Returns the minimum element of this stream according to the provided key extractor function.This is a terminal operation.
- Type Parameters:
V
- the type of theComparable
sort key- Parameters:
keyExtractor
- a non-interfering, stateless function- Returns:
- an
OptionalDouble
describing the first element of this stream for which the lowest value was returned by key extractor, or an emptyOptionalDouble
if the stream is empty - Since:
- 0.1.2
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minByInt
Returns the minimum element of this stream according to the provided key extractor function.This is a terminal operation.
- Parameters:
keyExtractor
- a non-interfering, stateless function- Returns:
- an
OptionalDouble
describing the first element of this stream for which the lowest value was returned by key extractor, or an emptyOptionalDouble
if the stream is empty - Since:
- 0.1.2
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minByLong
Returns the minimum element of this stream according to the provided key extractor function.This is a terminal operation.
- Parameters:
keyExtractor
- a non-interfering, stateless function- Returns:
- an
OptionalDouble
describing the first element of this stream for which the lowest value was returned by key extractor, or an emptyOptionalDouble
if the stream is empty - Since:
- 0.1.2
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minByDouble
Returns the minimum element of this stream according to the provided key extractor function.This is a terminal operation.
- Parameters:
keyExtractor
- a non-interfering, stateless function- Returns:
- an
OptionalDouble
describing the first element of this stream for which the lowest value was returned by key extractor, or an emptyOptionalDouble
if the stream is empty - Since:
- 0.1.2
-
max
- Specified by:
max
in interfaceDoubleStream
-
max
Returns the maximum element of this stream according to the providedComparator
.This is a terminal operation.
- Parameters:
comparator
- a non-interfering, statelessComparator
to compare elements of this stream- Returns:
- an
OptionalDouble
describing the maximum element of this stream, or an emptyOptionalDouble
if the stream is empty
-
maxBy
Returns the maximum element of this stream according to the provided key extractor function.This is a terminal operation.
- Type Parameters:
V
- the type of theComparable
sort key- Parameters:
keyExtractor
- a non-interfering, stateless function- Returns:
- an
OptionalDouble
describing the first element of this stream for which the highest value was returned by key extractor, or an emptyOptionalDouble
if the stream is empty - Since:
- 0.1.2
-
maxByInt
Returns the maximum element of this stream according to the provided key extractor function.This is a terminal operation.
- Parameters:
keyExtractor
- a non-interfering, stateless function- Returns:
- an
OptionalDouble
describing the first element of this stream for which the highest value was returned by key extractor, or an emptyOptionalDouble
if the stream is empty - Since:
- 0.1.2
-
maxByLong
Returns the maximum element of this stream according to the provided key extractor function.This is a terminal operation.
- Parameters:
keyExtractor
- a non-interfering, stateless function- Returns:
- an
OptionalDouble
describing the first element of this stream for which the highest value was returned by key extractor, or an emptyOptionalDouble
if the stream is empty - Since:
- 0.1.2
-
maxByDouble
Returns the maximum element of this stream according to the provided key extractor function.This is a terminal operation.
- Parameters:
keyExtractor
- a non-interfering, stateless function- Returns:
- an
OptionalDouble
describing the first element of this stream for which the highest value was returned by key extractor, or an emptyOptionalDouble
if the stream is empty - Since:
- 0.1.2
-
count
public long count()- Specified by:
count
in interfaceDoubleStream
-
count
Counts the number of elements in the stream that satisfy the predicate.This is a terminal operation.
- Parameters:
predicate
- a non-interfering , stateless predicate to apply to stream elements. Only elements passing the predicate will be counted.- Returns:
- the count of elements in this stream satisfying the predicate.
-
average
- Specified by:
average
in interfaceDoubleStream
-
summaryStatistics
- Specified by:
summaryStatistics
in interfaceDoubleStream
-
anyMatch
- Specified by:
anyMatch
in interfaceDoubleStream
-
allMatch
- Specified by:
allMatch
in interfaceDoubleStream
-
noneMatch
- Specified by:
noneMatch
in interfaceDoubleStream
-
findFirst
- Specified by:
findFirst
in interfaceDoubleStream
-
findFirst
Returns anOptionalDouble
describing the first element of this stream, which matches given predicate, or an emptyOptionalDouble
if there's no matching element.This is a short-circuiting terminal operation.
- Parameters:
predicate
- a non-interfering , stateless predicate which returned value should match- Returns:
- an
OptionalDouble
describing the first matching element of this stream, or an emptyOptionalDouble
if there's no matching element - See Also:
-
findAny
- Specified by:
findAny
in interfaceDoubleStream
-
findAny
Returns anOptionalDouble
describing some element of the stream, which matches given predicate, or an emptyOptionalDouble
if there's no matching element.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(DoublePredicate)
instead.)- Parameters:
predicate
- a non-interfering , stateless predicate which returned value should match- Returns:
- an
OptionalDouble
describing some matching element of this stream, or an emptyOptionalDouble
if there's no matching element - See Also:
-
indexOf
Returns anOptionalLong
describing the zero-based index of the first element of this stream, which matches given predicate, or an emptyOptionalLong
if there's no matching element.This is a short-circuiting terminal operation.
- Parameters:
predicate
- a non-interfering , stateless predicate which returned value should match- Returns:
- an
OptionalLong
describing the index of the first matching element of this stream, or an emptyOptionalLong
if there's no matching element. - Since:
- 0.4.0
- See Also:
-
boxed
- Specified by:
boxed
in interfaceDoubleStream
-
sequential
- Specified by:
sequential
in interfaceBaseStream<Double,
DoubleStream> - Specified by:
sequential
in interfaceDoubleStream
- Overrides:
sequential
in classBaseStreamEx<Double,
DoubleStream, Spliterator.OfDouble, DoubleStreamEx>
-
parallel
Description copied from class:BaseStreamEx
If this stream was created using
BaseStreamEx.parallel(ForkJoinPool)
, the new stream forgets about supplied customForkJoinPool
and its terminal operation will be executed in common pool.- Specified by:
parallel
in interfaceBaseStream<Double,
DoubleStream> - Specified by:
parallel
in interfaceDoubleStream
- Overrides:
parallel
in classBaseStreamEx<Double,
DoubleStream, Spliterator.OfDouble, DoubleStreamEx>
-
parallel
Description copied from class:BaseStreamEx
Returns an equivalent stream that is parallel and bound to the suppliedForkJoinPool
.This is an intermediate operation.
The terminal operation of this stream or any derived stream (except the streams created via
BaseStreamEx.parallel()
orBaseStreamEx.sequential()
methods) will be executed inside the suppliedForkJoinPool
. If current thread does not belong to that pool, it will wait till calculation finishes.- Overrides:
parallel
in classBaseStreamEx<Double,
DoubleStream, Spliterator.OfDouble, DoubleStreamEx> - Parameters:
fjp
- aForkJoinPool
to submit the stream operation to.- Returns:
- a parallel stream bound to the supplied
ForkJoinPool
-
iterator
- Specified by:
iterator
in interfaceBaseStream<Double,
DoubleStream> - Specified by:
iterator
in interfaceDoubleStream
-
append
Returns a newDoubleStreamEx
which is a concatenation of this stream and the stream containing supplied valuesThis is a quasi-intermediate operation.
- Parameters:
values
- the values to append to the stream- Returns:
- the new stream
-
append
Creates a lazily concatenated stream whose elements are all the elements of this stream followed by all the elements of the other 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.- Parameters:
other
- the other stream- Returns:
- this stream appended by the other stream
- See Also:
-
prepend
Returns a newDoubleStreamEx
which is a concatenation of the stream containing supplied values and this streamThis is a quasi-intermediate operation.
- Parameters:
values
- the values to prepend to the stream- Returns:
- the new stream
-
prepend
Creates a lazily concatenated stream whose elements are all the elements of the other stream followed by all the elements of this 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.- Parameters:
other
- the other stream- Returns:
- this stream prepended by the other stream
- See Also:
-
pairMap
Returns a stream consisting of the results of applying the given function to the every adjacent pair of elements of this stream.This is a quasi-intermediate operation.
The output stream will contain one element less than this stream. If this stream contains zero or one element the output stream will be empty.
- Parameters:
mapper
- a non-interfering, stateless function to apply to each adjacent pair of this stream elements.- Returns:
- the new stream
- Since:
- 0.2.1
-
joining
Returns aString
which is the concatenation of the results of callingString.valueOf(double)
on each element of this stream, separated by the specified delimiter, in encounter order.This is a terminal operation.
- Parameters:
delimiter
- the delimiter to be used between each element- Returns:
- the result of concatenation. For empty input stream empty String is returned.
- Since:
- 0.3.1
-
joining
Returns aString
which is the concatenation of the results of callingString.valueOf(double)
on each element of this stream, separated by the specified delimiter, with the specified prefix and suffix in encounter order.This is a terminal operation.
- Parameters:
delimiter
- the delimiter to be used between each elementprefix
- the sequence of characters to be used at the beginning of the joined resultsuffix
- the sequence of characters to be used at the end of the joined result- Returns:
- the result of concatenation. For empty input stream
prefix + suffix
is returned. - Since:
- 0.3.1
-
takeWhile
Returns a stream consisting of all elements from this stream until the first element which does not match the given predicate is found.This is a short-circuiting stateful operation. It can be either intermediate or quasi-intermediate. When using with JDK 1.9 or higher it calls the corresponding JDK 1.9 implementation. When using with JDK 1.8 it uses own implementation.
While this operation is quite cheap for sequential stream, it can be quite expensive on parallel pipelines.
- Specified by:
takeWhile
in interfaceDoubleStream
- Parameters:
predicate
- a non-interfering, stateless predicate to apply to elements.- Returns:
- the new stream.
- Since:
- 0.3.6
- See Also:
-
takeWhileInclusive
Returns a stream consisting of all elements from this stream until the first element which does not match the given predicate is found (including the first mismatching element).This is a quasi-intermediate operation.
While this operation is quite cheap for sequential stream, it can be quite expensive on parallel pipelines.
- Parameters:
predicate
- a non-interfering, stateless predicate to apply to elements.- Returns:
- the new stream.
- Since:
- 0.5.5
- See Also:
-
dropWhile
Returns a stream consisting of all elements from this stream starting from the first element which does not match the given predicate. If the predicate is true for all stream elements, an empty stream is returned.This is a stateful operation. It can be either intermediate or quasi-intermediate. When using with JDK 1.9 or higher it calls the corresponding JDK 1.9 implementation. When using with JDK 1.8 it uses own implementation.
While this operation is quite cheap for sequential stream, it can be quite expensive on parallel pipelines.
- Specified by:
dropWhile
in interfaceDoubleStream
- Parameters:
predicate
- a non-interfering, stateless predicate to apply to elements.- Returns:
- the new stream.
- Since:
- 0.3.6
-
prefix
Returns a stream containing cumulative results of applying the accumulation function going left to right.This is a stateful quasi-intermediate operation.
This operation resembles
scanLeft(DoubleBinaryOperator)
, but unlikescanLeft
this operation is intermediate and accumulation function must be associative.This method cannot take all the advantages of parallel streams as it must process elements strictly left to right. Using an unordered source or removing the ordering constraint with
unordered()
may improve the parallel processing speed.- Parameters:
op
- an associative , non-interfering , stateless function for computing the next element based on the previous one- Returns:
- the new stream.
- Since:
- 0.6.1
- See Also:
-
chain
Description copied from class:BaseStreamEx
Applies the supplied function to this stream and returns the result of the function.This method can be used to add more functionality in the fluent style. For example, consider user-defined static method
batches(stream, n)
which breaks the stream into batches of given length. Normally you would writebatches(StreamEx.of(input).map(...), 10).filter(...)
. Using thechain()
method you can write in more fluent manner:StreamEx.of(input).map(...).chain(s -> batches(s, 10)).filter(...)
.You could even go further and define a method which returns a function like
<T> UnaryOperator<StreamEx<T>> batches(int n)
and use it like this:StreamEx.of(input).map(...).chain(batches(10)).filter(...)
.- Specified by:
chain
in classBaseStreamEx<Double,
DoubleStream, Spliterator.OfDouble, DoubleStreamEx> - Type Parameters:
U
- the type of the function result.- Parameters:
mapper
- function to invoke.- Returns:
- the result of the function invocation.
-
empty
Returns an empty sequentialDoubleStreamEx
.- Returns:
- an empty sequential stream
-
of
Returns a sequentialDoubleStreamEx
containing a single element.- Parameters:
element
- the single element- Returns:
- a singleton sequential stream
-
of
Returns a sequential orderedDoubleStreamEx
whose elements are the specified values.- Parameters:
elements
- the elements of the new stream- Returns:
- the new stream
-
of
Returns a sequentialDoubleStreamEx
with the specified range of the specified array as its source.- Parameters:
array
- the array, assumed to be unmodified during usestartInclusive
- the first index to cover, inclusiveendExclusive
- index immediately past the last index to cover- Returns:
- an
DoubleStreamEx
for the array range - Throws:
ArrayIndexOutOfBoundsException
- ifstartInclusive
is negative,endExclusive
is less thanstartInclusive
, orendExclusive
is greater than the array size- Since:
- 0.1.1
- See Also:
-
of
Returns a sequential orderedDoubleStreamEx
whose elements are the unboxed elements of supplied array.- Parameters:
array
- the array to create the stream from.- Returns:
- the new stream
- Since:
- 0.5.0
- See Also:
-
of
Returns a sequential orderedDoubleStreamEx
whose elements are the values in the suppliedDoubleBuffer
.The resulting stream covers only a portion of
DoubleBuffer
content which starts with position (inclusive) and ends with limit (exclusive). Changes in position and limit after the stream creation don't affect the stream.The resulting stream does not change the internal
DoubleBuffer
state.- Parameters:
buf
- theDoubleBuffer
to create a stream from- Returns:
- the new stream
- Since:
- 0.6.2
-
of
Returns a sequential orderedDoubleStreamEx
whose elements are the specified float values casted to double.- Parameters:
elements
- the elements of the new stream- Returns:
- the new stream
- Since:
- 0.2.0
-
of
Returns a sequentialDoubleStreamEx
with the specified range of the specified array as its source. Array values will be casted to double.- Parameters:
array
- the array, assumed to be unmodified during usestartInclusive
- the first index to cover, inclusiveendExclusive
- index immediately past the last index to cover- Returns:
- an
IntStreamEx
for the array range - Throws:
ArrayIndexOutOfBoundsException
- ifstartInclusive
is negative,endExclusive
is less thanstartInclusive
, orendExclusive
is greater than the array size- Since:
- 0.2.0
-
of
Returns aDoubleStreamEx
object which wraps givenDoubleStream
.The supplied stream must not be consumed or closed when this method is called. No operation must be performed on the supplied stream after it's wrapped.
- Parameters:
stream
- original stream- Returns:
- the wrapped stream
- Since:
- 0.0.8
-
of
Returns a sequentialDoubleStreamEx
created from givenSpliterator.OfDouble
.- Parameters:
spliterator
- a spliterator to create the stream from.- Returns:
- the new stream
- Since:
- 0.3.4
-
of
Returns a sequential, orderedDoubleStreamEx
created from givenPrimitiveIterator.OfDouble
.This method is roughly equivalent to
DoubleStreamEx.of(Spliterators.spliteratorUnknownSize(iterator, ORDERED))
, but may show better performance for parallel processing.Use this method only if you cannot provide better Stream source.
- Parameters:
iterator
- an iterator to create the stream from.- Returns:
- the new stream
- Since:
- 0.5.1
-
of
Returns a sequentialDoubleStreamEx
containing anOptionalDouble
value, if present, otherwise returns an emptyDoubleStreamEx
.- Parameters:
optional
- the optional to create a stream of- Returns:
- a stream with an
OptionalDouble
value if present, otherwise an empty stream - Since:
- 0.1.1
-
of
Returns a sequential orderedDoubleStreamEx
whose elements are the unboxed elements of supplied collection.- Parameters:
collection
- the collection to create the stream from.- Returns:
- the new stream
- See Also:
-
of
Returns an effectively unlimited stream of pseudorandomdouble
values, each between zero (inclusive) and one (exclusive) produced by givenRandom
object.A pseudorandom
double
value is generated as if it's the result of calling the methodRandom.nextDouble()
.- Parameters:
random
- aRandom
object to produce the stream from- Returns:
- a stream of pseudorandom
double
values - See Also:
-
of
Returns a stream producing the givenstreamSize
number of pseudorandomdouble
values, each between zero (inclusive) and one (exclusive) produced by givenRandom
object.A pseudorandom
double
value is generated as if it's the result of calling the methodRandom.nextDouble()
.- Parameters:
random
- aRandom
object to produce the stream fromstreamSize
- the number of values to generate- Returns:
- a stream of pseudorandom
double
values - See Also:
-
of
Returns an effectively unlimited stream of pseudorandomdouble
values, each conforming to the given origin (inclusive) and bound (exclusive) produced by givenRandom
object.- Parameters:
random
- aRandom
object to produce the stream fromrandomNumberOrigin
- the origin (inclusive) of each random valuerandomNumberBound
- the bound (exclusive) of each random value- Returns:
- a stream of pseudorandom
double
values, each with the given origin (inclusive) and bound (exclusive) - See Also:
-
of
public static DoubleStreamEx of(Random random, long streamSize, double randomNumberOrigin, double randomNumberBound) Returns a stream producing the givenstreamSize
number of pseudorandomdouble
values, each conforming to the given origin (inclusive) and bound (exclusive) produced by givenRandom
object.- Parameters:
random
- aRandom
object to produce the stream fromrandomNumberOrigin
- the origin (inclusive) of each random valuerandomNumberBound
- the bound (exclusive) of each random valuestreamSize
- the number of values to generate- Returns:
- a stream of pseudorandom
double
values, each with the given origin (inclusive) and bound (exclusive) - See Also:
-
iterate
Returns an infinite sequential orderedDoubleStreamEx
produced by iterative application of a functionf
to an initial elementseed
, producing a stream consisting ofseed
,f(seed)
,f(f(seed))
, etc.The first element (position
0
) in theDoubleStreamEx
will be the providedseed
. Forn > 0
, the element at positionn
, will be the result of applying the functionf
to the element at positionn - 1
.- Parameters:
seed
- the initial elementf
- a function to be applied to to the previous element to produce a new element- Returns:
- A new sequential
DoubleStream
- See Also:
-
iterate
Returns a sequential orderedDoubleStreamEx
produced by iterative application of a function to an initial element, conditioned on satisfying the supplied predicate. The stream terminates as soon as the predicate function returns false.DoubleStreamEx.iterate
should produce the same sequence of elements as produced by the corresponding for-loop:for (double index=seed; predicate.test(index); index = f.apply(index)) { ... }
The resulting sequence may be empty if the predicate does not hold on the seed value. Otherwise the first element will be the supplied seed value, the next element (if present) will be the result of applying the function f to the seed value, and so on iteratively until the predicate indicates that the stream should terminate.
- Parameters:
seed
- the initial elementpredicate
- a predicate to apply to elements to determine when the stream must terminate.f
- a function to be applied to the previous element to produce a new element- Returns:
- a new sequential
DoubleStreamEx
- Since:
- 0.6.0
- See Also:
-
generate
Returns an infinite sequential unordered stream where each element is generated by the providedDoubleSupplier
. This is suitable for generating constant streams, streams of random elements, etc.- Parameters:
s
- theDoubleSupplier
for generated elements- Returns:
- a new infinite sequential unordered
DoubleStreamEx
- See Also:
-
produce
Return an ordered stream produced by consecutive calls of the supplied producer until it returns false.The producer function may call the passed consumer any number of times and return true if the producer should be called again or false otherwise. It's guaranteed that the producer will not be called anymore, once it returns false.
This method is particularly useful when producer changes the mutable object which should be left in known state after the full stream consumption. Note however that if a short-circuiting operation is used, then the final state of the mutable object cannot be guaranteed.
- Parameters:
producer
- a predicate which calls the passed consumer to emit stream element(s) and returns true if it producer should be applied again.- Returns:
- the new stream
- Since:
- 0.6.0
-
constant
Returns a sequential unorderedDoubleStreamEx
of given length which elements are equal to supplied value.- Parameters:
value
- the constant valuelength
- the length of the stream- Returns:
- a new
DoubleStreamEx
- Since:
- 0.1.2
-
zip
Returns a sequentialDoubleStreamEx
containing the results of applying the given function to the corresponding pairs of values in given two arrays.- Parameters:
first
- the first arraysecond
- the second arraymapper
- a non-interfering, stateless function to apply to each pair of the corresponding array elements.- Returns:
- a new
DoubleStreamEx
- Throws:
IllegalArgumentException
- if length of the arrays differs.- Since:
- 0.2.1
-