org.eclipse.viatra.query.runtime.matchers.aggregators

Class DoubleSumOperator

java.lang.Object

org.eclipse.viatra.query.runtime.matchers.psystem.aggregations.AbstractMultisetAggregationOperator<Domain,AggregateResult,AggregateResult>

org.eclipse.viatra.query.runtime.matchers.psystem.aggregations.AbstractMemorylessAggregationOperator<java.lang.Double,java.lang.Double>

org.eclipse.viatra.query.runtime.matchers.aggregators.DoubleSumOperator

All Implemented Interfaces:

IMultisetAggregationOperator<java.lang.Double,java.lang.Double,java.lang.Double>

public class DoubleSumOperator
extends AbstractMemorylessAggregationOperator<java.lang.Double,java.lang.Double>

Incrementally computes the sum of java.lang.Double values

Since:

1.4

Field Summary

Fields

Modifier and Type	Field and Description
static DoubleSumOperator	INSTANCE

Method Summary

Modifier and Type	Method and Description
java.lang.Double	createNeutral()
java.lang.String	getName() A name or identifier of the operator.
java.lang.String	getShortDescription() A textual description of the operator.
boolean	isNeutral(java.lang.Double result)
java.lang.Double	update(java.lang.Double oldResult, java.lang.Double updateValue, boolean isInsertion)

Methods inherited from class org.eclipse.viatra.query.runtime.matchers.psystem.aggregations.AbstractMemorylessAggregationOperator

getAggregate

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final DoubleSumOperator INSTANCE

Method Detail

getShortDescription

public java.lang.String getShortDescription()

Description copied from interface: IMultisetAggregationOperator

A textual description of the operator.

getName

public java.lang.String getName()

Description copied from interface: IMultisetAggregationOperator

A name or identifier of the operator.

createNeutral

public java.lang.Double createNeutral()

Returns:

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

isNeutral

public boolean isNeutral(java.lang.Double 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 java.lang.Double update(java.lang.Double oldResult,
                               java.lang.Double 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)