Spliterators.AbstractDoubleSpliterator
public
static
abstract
class
Spliterators.AbstractDoubleSpliterator
extends Object
implements
Spliterator.OfDouble
java.lang.Object | |
↳ | java.util.Spliterators.AbstractDoubleSpliterator |
An abstract Spliterator.OfDouble
that implements
trySplit
to permit limited parallelism.
To implement a spliterator an extending class need only
implement tryAdvance
. The extending class should override
forEachRemaining
if it can provide a more performant implementation.
Summary
Inherited constants |
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Protected constructors | |
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AbstractDoubleSpliterator(long est, int additionalCharacteristics)
Creates a spliterator reporting the given estimated size and characteristics. |
Public methods | |
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int
|
characteristics()
Returns a set of characteristics of this Spliterator and its elements. |
long
|
estimateSize()
Returns an estimate of the number of elements that would be
encountered by a |
Spliterator.OfDouble
|
trySplit()
If this spliterator can be partitioned, returns a Spliterator covering elements, that will, upon return from this method, not be covered by this Spliterator. This implementation permits limited parallelism. |
Inherited methods | |
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Protected constructors
AbstractDoubleSpliterator
protected AbstractDoubleSpliterator (long est, int additionalCharacteristics)
Creates a spliterator reporting the given estimated size and characteristics.
Parameters | |
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est |
long : the estimated size of this spliterator if known, otherwise
Long.MAX_VALUE . |
additionalCharacteristics |
int : properties of this spliterator's
source or elements. If SIZED is reported then this
spliterator will additionally report SUBSIZED . |
Public methods
characteristics
public int characteristics ()
Returns a set of characteristics of this Spliterator and its
elements. The result is represented as ORed values from ORDERED
, DISTINCT
, SORTED
, SIZED
,
NONNULL
, IMMUTABLE
, CONCURRENT
,
SUBSIZED
. Repeated calls to characteristics()
on
a given spliterator, prior to or in-between calls to trySplit
,
should always return the same result.
If a Spliterator reports an inconsistent set of characteristics (either those returned from a single invocation or across multiple invocations), no guarantees can be made about any computation using this Spliterator.
Implementation Requirements:
- This implementation returns the characteristics as reported when created.
Returns | |
---|---|
int |
a representation of characteristics |
estimateSize
public long estimateSize ()
Returns an estimate of the number of elements that would be
encountered by a forEachRemaining(Consumer)
traversal, or returns Long.MAX_VALUE
if infinite, unknown, or too expensive to compute.
If this Spliterator is SIZED
and has not yet been partially
traversed or split, or this Spliterator is SUBSIZED
and has
not yet been partially traversed, this estimate must be an accurate
count of elements that would be encountered by a complete traversal.
Otherwise, this estimate may be arbitrarily inaccurate, but must decrease
as specified across invocations of trySplit()
.
Implementation Requirements:
- This implementation returns the estimated size as reported when created and, if the estimate size is known, decreases in size when split.
Returns | |
---|---|
long |
the estimated size, or Long.MAX_VALUE if infinite,
unknown, or too expensive to compute. |
trySplit
public Spliterator.OfDouble trySplit ()
If this spliterator can be partitioned, returns a Spliterator covering elements, that will, upon return from this method, not be covered by this Spliterator.
If this Spliterator is ORDERED
, the returned Spliterator
must cover a strict prefix of the elements.
Unless this Spliterator covers an infinite number of elements,
repeated calls to trySplit()
must eventually return null
.
Upon non-null return:
- the value reported for
estimateSize()
before splitting, must, after splitting, be greater than or equal toestimateSize()
for this and the returned Spliterator; and - if this Spliterator is
SUBSIZED
, thenestimateSize()
for this spliterator before splitting must be equal to the sum ofestimateSize()
for this and the returned Spliterator after splitting.
This method may return null
for any reason,
including emptiness, inability to split after traversal has
commenced, data structure constraints, and efficiency
considerations.
This implementation permits limited parallelism.
Returns | |
---|---|
Spliterator.OfDouble |
a Spliterator covering some portion of the
elements, or null if this spliterator cannot be split |