edu.washington.cs.knowitall.extractor
Class ExtractorUnion<S,T>

java.lang.Object
  edu.washington.cs.knowitall.extractor.Extractor<S,T>
      edu.washington.cs.knowitall.extractor.ExtractorUnion<S,T>

Type Parameters:

S -

T -

public class ExtractorUnion<S,T>
extends Extractor<S,T>

Takes the union of the output of multiple extractors. The output of this extractor is the output of the others concatenated together.

Author:

afader

Constructor Summary

ExtractorUnion()
Constructs an empty extractor that will return an empty set of results from any given input.

ExtractorUnion(List<Extractor<S,T>> extractors)
Constructs a new extractor that returns the union of the output from each of the given extractors.

Method Summary

void	addExtractor(Extractor<S,T> extractor) Adds the given extractor to the union.
protected Collection<T>	extractCandidates(S source) Returns the results from each extractor.

Methods inherited from class edu.washington.cs.knowitall.extractor.Extractor

addMapper, compose, extract, getMappers

Methods inherited from class java.lang.Object

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

Constructor Detail

ExtractorUnion

public ExtractorUnion()

Constructs an empty extractor that will return an empty set of results from any given input.

ExtractorUnion

public ExtractorUnion(List<Extractor<S,T>> extractors)

Constructs a new extractor that returns the union of the output from each of the given extractors.

Parameters:

extractors -

Method Detail

addExtractor

public void addExtractor(Extractor<S,T> extractor)

Adds the given extractor to the union.

Parameters:

extractor -

extractCandidates

protected Collection<T> extractCandidates(S source)
                                   throws ExtractorException

Returns the results from each extractor. If there are no extractors in the union, returns an empty Iterable.

Specified by:

extractCandidates in class Extractor<S,T>

Parameters:

source - the source to extract from.

Returns:

an iterable object over the candidate extractions.

Throws:

ExtractorException - if unable to extract