simplenlg.aggregation

Class AggregationRule

java.lang.Object

simplenlg.aggregation.AggregationRule

Direct Known Subclasses:

BackwardConjunctionReductionRule, ClauseCoordinationRule, ForwardConjunctionReductionRule

public abstract class AggregationRule
extends Object

This class represents an aggregation rule. All such rules need to implement an apply(NLGElement, NLGElement) which takes an arbitrary number of NLGElements and perform some form of aggregation on them, returning an SPhraseSpec as a result, or null if the operation fails.

Author:

Albert Gatt, University of Malta and University of Aberdeen

Field Summary

Fields

Modifier and Type	Field and Description
protected NLGFactory	factory

Constructor Summary

Constructors

Constructor and Description
AggregationRule() Creates a new instance of AggregationRule

Method Summary

Modifier and Type	Method and Description
List<NLGElement>	apply(List<NLGElement> phrases) Performs aggregation on an arbitrary number of elements in a list.
NLGElement	apply(NLGElement phrase) Perform aggregation on a single phrase.
abstract NLGElement	apply(NLGElement sentence1, NLGElement sentence2) Performs aggregation on a pair of sentences.
NLGFactory	getFactory()
void	setFactory(NLGFactory factory) Set the factory that the rule should use to create phrases.

Methods inherited from class java.lang.Object

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

Field Detail

factory

protected NLGFactory factory

Constructor Detail

AggregationRule

public AggregationRule()

Creates a new instance of AggregationRule

Method Detail

setFactory

public void setFactory(NLGFactory factory)

Set the factory that the rule should use to create phrases.

Parameters:

factory - the factory

getFactory

public NLGFactory getFactory()

Returns:

the factory being used by this rule to create phrases

apply

public List<NLGElement> apply(List<NLGElement> phrases)

Performs aggregation on an arbitrary number of elements in a list. This method calls {apply(NLGElement, NLGElement) on all pairs of elements in the list, recursively aggregating whenever it can.

Parameters:

phrases - the sentences

Returns:

a list containing the phrases, such that, for any two phrases s1 and s2, if apply(NLGElement, NLGElement) succeeds on s1 and s2, the list contains the result; otherwise, the list contains s1 and s2.

apply

public NLGElement apply(NLGElement phrase)

Perform aggregation on a single phrase. This method only works on a CoordinatedPhraseElement, in which case it calls apply(List) on the children of the coordinated phrase, returning a coordinated phrase whose children are the result.

Returns:

aggregated result

apply

public abstract NLGElement apply(NLGElement sentence1,
                                 NLGElement sentence2)

Performs aggregation on a pair of sentences. This is the only method that extensions of AggregationRule need to implement.

Parameters:

sentence1 - the first sentence

sentence2 - the second sentence

Returns:

an aggregated sentence, if the method succeeds, null otherwise