Package tools.refinery.interpreter.matchers.aggregators

Class LongSumOperator

java.lang.Object

tools.refinery.interpreter.matchers.psystem.aggregations.AbstractMemorylessAggregationOperator<Long,Long>

tools.refinery.interpreter.matchers.aggregators.LongSumOperator

All Implemented Interfaces:

IMultisetAggregationOperator<Long,Long,Long>

public class LongSumOperator
extends AbstractMemorylessAggregationOperator<Long,Long>

Incrementally computes the sum of java.lang.Long values

Since:

1.4

Field Summary

Fields

Modifier and Type	Field	Description
static final LongSumOperator	INSTANCE

Method Summary

Modifier and Type	Method	Description
Long	aggregateStream(Stream<Long> stream)	Calculates the aggregate results from a given stream of values; all values are considered as inserted
Long	createNeutral()
String	getName()	A name or identifier of the operator.
String	getShortDescription()	A textual description of the operator.
boolean	isNeutral(Long result)
Long	update(Long oldResult, Long updateValue, boolean isInsertion)

Methods inherited from class tools.refinery.interpreter.matchers.psystem.aggregations.AbstractMemorylessAggregationOperator

clone, getAggregate

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface tools.refinery.interpreter.matchers.psystem.aggregations.IMultisetAggregationOperator

combine, contains, prettyPrint

Field Details

INSTANCE

public static final LongSumOperator INSTANCE

Method Details

getShortDescription

public String getShortDescription()

Description copied from interface: IMultisetAggregationOperator

A textual description of the operator.

getName

public String getName()

Description copied from interface: IMultisetAggregationOperator

A name or identifier of the operator.

createNeutral

public Long createNeutral()

Returns:

the neutral element, i.e. the interim result of aggregating an empty multiset.

isNeutral

public boolean isNeutral(Long result)

Returns:

true if the interim result is equivalent to the neutral element, as if there are no values in the multiset. Must return true if the multiset is empty.

update

public Long update(Long oldResult,
 Long updateValue,
 boolean isInsertion)

Returns:

an updated intermediate result, changed to reflect that a given object was added to / removed from the multiset (as indicated by the parameter isInsertion)

aggregateStream

public Long aggregateStream(Stream<Long> stream)

Description copied from interface: IMultisetAggregationOperator

Calculates the aggregate results from a given stream of values; all values are considered as inserted

Returns:

the aggregate result, or null if no result can be calculated (e.g. because of an empty stream)

Since:

2.0