Package tools.refinery.interpreter.matchers.aggregators

Class ExtremumOperator<T extends Comparable<T>>

java.lang.Object

tools.refinery.interpreter.matchers.aggregators.ExtremumOperator<T>

All Implemented Interfaces:

IMultisetAggregationOperator<T,SortedMap<T,Integer>,T>

public class ExtremumOperator<T extends Comparable<T>>
extends Object
implements IMultisetAggregationOperator<T,SortedMap<T,Integer>,T>

Incrementally computes the minimum or maximum of java.lang.Comparable values, using the default comparison

Since:

1.4

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	ExtremumOperator.Extreme

Method Summary

Modifier and Type	Method	Description
T	aggregateStream(Stream<T> stream)	Calculates the aggregate results from a given stream of values; all values are considered as inserted
SortedMap<T,Integer>	clone(SortedMap<T,Integer> original)	Clones the given accumulator (with all its internal contents).
SortedMap<T,Integer>	createNeutral()
T	getAggregate(SortedMap<T,Integer> result)
static <T extends Comparable<T>> ExtremumOperator<T>	getMax()
static <T extends Comparable<T>> ExtremumOperator<T>	getMin()
String	getName()	A name or identifier of the operator.
String	getShortDescription()	A textual description of the operator.
boolean	isNeutral(SortedMap<T,Integer> result)
SortedMap<T,Integer>	update(SortedMap<T,Integer> oldResult, T updateValue, boolean isInsertion)

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

Method Details

getMin

public static <T extends Comparable<T>>
ExtremumOperator<T> getMin()

getMax

public static <T extends Comparable<T>>
ExtremumOperator<T> getMax()

getShortDescription

public String getShortDescription()

Description copied from interface: IMultisetAggregationOperator

A textual description of the operator.

Specified by:

getShortDescription in interface IMultisetAggregationOperator<T extends Comparable<T>,SortedMap<T extends Comparable<T>,Integer>,T extends Comparable<T>>

getName

public String getName()

Description copied from interface: IMultisetAggregationOperator

A name or identifier of the operator.

Specified by:

getName in interface IMultisetAggregationOperator<T extends Comparable<T>,SortedMap<T extends Comparable<T>,Integer>,T extends Comparable<T>>

createNeutral

public SortedMap<T,Integer> createNeutral()

Specified by:

createNeutral in interface IMultisetAggregationOperator<T extends Comparable<T>,SortedMap<T extends Comparable<T>,Integer>,T extends Comparable<T>>

Returns:

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

Since:

2.0

isNeutral

public boolean isNeutral(SortedMap<T,Integer> result)

Specified by:

isNeutral in interface IMultisetAggregationOperator<T extends Comparable<T>,SortedMap<T extends Comparable<T>,Integer>,T extends Comparable<T>>

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.

Since:

2.0

update

public SortedMap<T,Integer> update(SortedMap<T,Integer> oldResult,
 T updateValue,
 boolean isInsertion)

Specified by:

update in interface IMultisetAggregationOperator<T extends Comparable<T>,SortedMap<T extends Comparable<T>,Integer>,T extends Comparable<T>>

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)

Since:

2.0

getAggregate

public T getAggregate(SortedMap<T,Integer> result)

Specified by:

getAggregate in interface IMultisetAggregationOperator<T extends Comparable<T>,SortedMap<T extends Comparable<T>,Integer>,T extends Comparable<T>>

Returns:

the aggregate result obtained from the given intermediate result. May be null to indicate that the current multiset cannot be aggregated (e.g. 0 elements have no minimum).

Since:

2.0

aggregateStream

public T aggregateStream(Stream<T> stream)

Description copied from interface: IMultisetAggregationOperator

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

Specified by:

aggregateStream in interface IMultisetAggregationOperator<T extends Comparable<T>,SortedMap<T extends Comparable<T>,Integer>,T extends Comparable<T>>

Returns:

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

Since:

2.0

clone

public SortedMap<T,Integer> clone(SortedMap<T,Integer> original)

Description copied from interface: IMultisetAggregationOperator

Clones the given accumulator (with all its internal contents).

Specified by:

clone in interface IMultisetAggregationOperator<T extends Comparable<T>,SortedMap<T extends Comparable<T>,Integer>,T extends Comparable<T>>

Since:

2.4