edu.stanford.nlp.pipeline.BinarizerAnnotator Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of stanford-corenlp Show documentation

Stanford CoreNLP provides a set of natural language analysis tools which can take raw English language text input and give the base forms of words, their parts of speech, whether they are names of companies, people, etc., normalize dates, times, and numeric quantities, mark up the structure of sentences in terms of phrases and word dependencies, and indicate which noun phrases refer to the same entities. It provides the foundational building blocks for higher level text understanding applications.

There is a newer version: 4.5.7

Show newest version

package edu.stanford.nlp.pipeline;

import java.util.Arrays;
import java.util.Collections;
import java.util.Properties;
import java.util.Set;

import edu.stanford.nlp.ling.CoreAnnotation;
import edu.stanford.nlp.ling.CoreAnnotations;
import edu.stanford.nlp.parser.lexparser.TreebankLangParserParams;
import edu.stanford.nlp.parser.lexparser.TreeBinarizer;
import edu.stanford.nlp.trees.Tree;
import edu.stanford.nlp.trees.Trees;
import edu.stanford.nlp.trees.TreeCoreAnnotations;
import edu.stanford.nlp.util.ArraySet;
import edu.stanford.nlp.util.CoreMap;
import edu.stanford.nlp.util.ReflectionLoading;

/**
 * This annotator takes unbinarized trees (from the parser annotator
 * or elsewhere) and binarizes them in the attachment.
 * 

 * Note that this functionality is also built in to the
 * ParserAnnotator.  However, this can be used in situations where the
 * trees come from somewhere other than the parser.  Conversely, the
 * ParserAnnotator may have more options for the binarizer which are
 * not implemented here.
 *
 * @author John Bauer
 */
public class BinarizerAnnotator implements Annotator {

  private static final String DEFAULT_TLPP_CLASS = "edu.stanford.nlp.parser.lexparser.EnglishTreebankParserParams";

  private final TreeBinarizer binarizer;
  private final String tlppClass;

  public BinarizerAnnotator(String annotatorName, Properties props) {
    this.tlppClass = props.getProperty(annotatorName + ".tlppClass", DEFAULT_TLPP_CLASS);
    TreebankLangParserParams tlpp = ReflectionLoading.loadByReflection(tlppClass);
    this.binarizer = TreeBinarizer.simpleTreeBinarizer(tlpp.headFinder(), tlpp.treebankLanguagePack());
  }

  public String signature(String annotatorName, Properties props) {
    // String tlppClass = props.getProperty(annotatorName + ".tlppClass", DEFAULT_TLPP_CLASS);
    return tlppClass;
  }

  @Override
  public void annotate(Annotation annotation) {
    if (annotation.containsKey(CoreAnnotations.SentencesAnnotation.class)) {
      for (CoreMap sentence : annotation.get(CoreAnnotations.SentencesAnnotation.class)) {
        doOneSentence(sentence);
      }
    } else {
      throw new RuntimeException("unable to find sentences in: " + annotation);
    }
  }

  private void doOneSentence(CoreMap sentence) {
    Tree tree = sentence.get(TreeCoreAnnotations.TreeAnnotation.class);
    Tree binarized;
    if (isBinarized(tree)) {
      binarized = tree;
    } else {
      binarized = binarizer.transformTree(tree);
    }
    Trees.convertToCoreLabels(binarized);
    sentence.set(TreeCoreAnnotations.BinarizedTreeAnnotation.class, binarized);
  }

  /**
   * Recursively check that a tree is not already binarized.
   */
  private static boolean isBinarized(Tree tree) {
    if (tree.isLeaf()) {
      return true;
    }

    if (tree.children().length > 2) {
      return false;
    }

    for (Tree child : tree.children()) {
      if (!isBinarized(child)) {
        return false;
      }
    }

    return true;
  }

  @Override
  public Set> requires() {
    return Collections.unmodifiableSet(new ArraySet<>(Arrays.asList(
        CoreAnnotations.TokensAnnotation.class,
        CoreAnnotations.SentencesAnnotation.class,
        TreeCoreAnnotations.TreeAnnotation.class
    )));
  }

  @Override
  public Set> requirementsSatisfied() {
    return Collections.singleton(TreeCoreAnnotations.BinarizedTreeAnnotation.class);
  }

}