001/** 
002 * Copyright (c) 2007-2012, Regents of the University of Colorado 
003 * All rights reserved.
004 * 
005 * Redistribution and use in source and binary forms, with or without
006 * modification, are permitted provided that the following conditions are met:
007 * 
008 * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 
009 * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. 
010 * Neither the name of the University of Colorado at Boulder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. 
011 * 
012 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
013 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
014 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
015 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
016 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
017 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
018 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
019 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
020 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
021 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
022 * POSSIBILITY OF SUCH DAMAGE. 
023 */
024package org.cleartk.ml.feature.function;
025
026import java.util.ArrayList;
027import java.util.List;
028
029import org.apache.uima.jcas.JCas;
030import org.apache.uima.jcas.tcas.Annotation;
031import org.cleartk.ml.Feature;
032import org.cleartk.ml.feature.extractor.CleartkExtractorException;
033import org.cleartk.ml.feature.extractor.FeatureExtractor1;
034
035import com.google.common.base.Function;
036
037/**
038 * <br>
039 * Copyright (c) 2007-2012, Regents of the University of Colorado <br>
040 * All rights reserved.
041 * 
042 * 
043 * @author Steven Bethard
044 */
045public class FeatureFunctionExtractor<T extends Annotation> implements FeatureExtractor1<T> {
046
047  /**
048   * Specify what to do with the base features created by the passed in feature extractor.
049   */
050  public static enum BaseFeatures {
051    /**
052     * include the base features in the returned features.
053     */
054    INCLUDE,
055    /**
056     * exclude the base features from the returned features.
057     */
058    EXCLUDE,
059  }
060
061  public FeatureFunctionExtractor(
062      FeatureExtractor1<T> extractor,
063      FeatureFunction... featureFunctions) {
064    this(extractor, BaseFeatures.INCLUDE, featureFunctions);
065  }
066
067  /**
068   * @param baseFeatures
069   *          determines if the base features created by the extractor parameter will be returned by
070   *          the extract method.
071   */
072  public FeatureFunctionExtractor(
073      FeatureExtractor1<T> extractor,
074      BaseFeatures baseFeatures,
075      FeatureFunction... featureFunctions) {
076    this.extractor = extractor;
077    this.baseFeatures = baseFeatures;
078    this.featureFunctions = featureFunctions;
079  }
080
081  public List<Feature> extract(JCas jCas, T focusAnnotation) throws CleartkExtractorException {
082    List<Feature> returnValues = new ArrayList<Feature>();
083    List<Feature> features = this.extractor.extract(jCas, focusAnnotation);
084    if (baseFeatures == BaseFeatures.INCLUDE)
085      returnValues.addAll(features);
086    for (Function<Feature, List<Feature>> featureFunction : this.featureFunctions) {
087      returnValues.addAll(apply(featureFunction, features));
088    }
089    return returnValues;
090  }
091
092  public static List<Feature> apply(
093      Function<Feature, List<Feature>> featureFunction,
094      List<Feature> features) {
095    List<Feature> returnValues = new ArrayList<Feature>();
096    for (Feature feature : features) {
097      returnValues.addAll(featureFunction.apply(feature));
098    }
099    return returnValues;
100  }
101
102  private FeatureExtractor1<T> extractor;
103
104  private FeatureFunction[] featureFunctions;
105
106  private BaseFeatures baseFeatures;
107}