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

Class IntegerSumOperator

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.Integer,java.lang.Integer>

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

All Implemented Interfaces:

IMultisetAggregationOperator<java.lang.Integer,java.lang.Integer,java.lang.Integer>

public class IntegerSumOperator
extends AbstractMemorylessAggregationOperator<java.lang.Integer,java.lang.Integer>

Incrementally computes the sum of java.lang.Integer values

Since:

1.4

Field Summary

Fields

Modifier and Type	Field and Description
static IntegerSumOperator	INSTANCE

Method Summary

Modifier and Type	Method and Description
java.lang.Integer	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.Integer result)
java.lang.Integer	update(java.lang.Integer oldResult, java.lang.Integer 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 IntegerSumOperator 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.Integer createNeutral()

Returns:

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

isNeutral

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