uk.ac.starlink.ttools.task

Interface Aggregator

public interface Aggregator

Defines an aggregation operation. An instance of this class can take multiple values associated with a given metadata item, and collapse them down to a single value.

Since:

16 Nov 2022

Author:

Mark Taylor

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	Aggregator.Accumulator Can accumulate multiple data items of a consistent type and yield an aggregate value corresponding to the set.
static interface	Aggregator.Aggregation Object that can manage aggregation for a given type of input data.

Method Summary

Modifier and Type	Method and Description
Aggregator.Aggregation	createAggregation(ValueInfo info) Creates an object that can manage aggregation for data described by given metadata.
String	getDescription() Returns a short textual description for this aggregator.
String	getName() Returns the name of this aggregator.

Method Detail

getName

String getName()

Returns the name of this aggregator.

Returns:

user-readable short name

getDescription

String getDescription()

Returns a short textual description for this aggregator.

Returns:

plain text description

createAggregation

Aggregator.Aggregation createAggregation(ValueInfo info)

Creates an object that can manage aggregation for data described by given metadata. If the metadata describes data that is not suitable for use by this object, null is returned.

Parameters:

info - input data description

Returns:

new aggregation, or null