edu.stanford.nlp.parser.common.ParserUtils 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.parser.common;

import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import edu.stanford.nlp.ling.HasTag;
import edu.stanford.nlp.ling.HasWord;
import edu.stanford.nlp.trees.LabeledScoredTreeFactory;
import edu.stanford.nlp.trees.Tree;
import edu.stanford.nlp.trees.TreeFactory;


/**
 * Factor out some useful methods more than lexparser module may want.
 */
public class ParserUtils {

  private ParserUtils() {} // static methods

  /**
   * Construct a fall through tree in case we can't parse this sentence.
   *
   * @param words Words of the sentence that didn't parse
   * @return A tree with X for all the internal nodes.
   *     Preterminals have the right tag if the words are tagged.
   */
  public static Tree xTree(List words) {
    TreeFactory treeFactory = new LabeledScoredTreeFactory();
    List lst2 = new ArrayList<>();
    for (HasWord obj : words) {
      String s = obj.word();
      Tree t = treeFactory.newLeaf(s);
      String tag = "XX";
      if (obj instanceof HasTag) {
        if (((HasTag) obj).tag() != null) {
          tag = ((HasTag) obj).tag();
        }
      }
      Tree t2 = treeFactory.newTreeNode(tag, Collections.singletonList(t));
      lst2.add(t2);
    }
    return treeFactory.newTreeNode("X", lst2);
  }

  public static void printOutOfMemory(PrintWriter pw) {
    pw.println();
    pw.println("*******************************************************");
    pw.println("***  WARNING!! OUT OF MEMORY! THERE WAS NOT ENOUGH  ***");
    pw.println("***  MEMORY TO RUN ALL PARSERS.  EITHER GIVE THE    ***");
    pw.println("***  JVM MORE MEMORY, SET THE MAXIMUM SENTENCE      ***");
    pw.println("***  LENGTH WITH -maxLength, OR PERHAPS YOU ARE     ***");
    pw.println("***  HAPPY TO HAVE THE PARSER FALL BACK TO USING    ***");
    pw.println("***  A SIMPLER PARSER FOR VERY LONG SENTENCES.      ***");
    pw.println("*******************************************************");
    pw.println();
  }

}