MSTReader.java

///////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2007 University of Texas at Austin and (C) 2005
// University of Pennsylvania and Copyright (C) 2002, 2003 University
// of Massachusetts Amherst, Department of Computer Science.
//
// This software is licensed under the terms of the Common Public
// License, Version 1.0 or (at your option) any subsequent version.
// 
// The license is approved by the Open Source Initiative, and is
// available from their website at http://www.opensource.org.
///////////////////////////////////////////////////////////////////////////////
package mstparser.io;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import mstparser.DependencyInstance;
import mstparser.Util;

/**
 * A reader for files in MST format.
 *
 * <p> Created: Sat Nov 10 15:25:10 2001 </p>
 *
 * @author Jason Baldridge
 * @version $Id: MSTReader.java 94 2007-01-17 17:05:12Z jasonbaldridge $
 * @see mstparser.io.DependencyReader
 */
public class MSTReader extends DependencyReader {

    @Override
    public DependencyInstance getNext() throws IOException {

        String line = inputReader.readLine();
        String pos_line = inputReader.readLine();
        String deprel_line = labeled ? inputReader.readLine() : pos_line;
        String heads_line = inputReader.readLine();
        String conf_line = confScores ? inputReader.readLine() : "";
        inputReader.readLine(); // blank line

        if (line == null) {
            inputReader.close();
            return null;
        }

        String[] forms = line.split("\t");
        String[] pos = pos_line.split("\t");
        String[] deprels = deprel_line.split("\t");
        int[] heads = Util.stringsToInts(heads_line.split("\t"));

        String[] forms_new = new String[forms.length + 1];
        String[] pos_new = new String[pos.length + 1];
        String[] deprels_new = new String[deprels.length + 1];
        int[] heads_new = new int[heads.length + 1];

        forms_new[0] = "<root>";
        pos_new[0] = "<root-POS>";
        deprels_new[0] = "<no-type>";
        heads_new[0] = -1;
        for (int i = 0; i < forms.length; i++) {
            forms_new[i + 1] = normalize(forms[i], null);
            pos_new[i + 1] = pos[i];
            deprels_new[i + 1] = labeled ? deprels[i] : "<no-type>";
            heads_new[i + 1] = heads[i];
        }

        double[] confs_new = null;
        if (confScores) {
            double[] confs = Util.stringsToDoubles(conf_line.split("\t"));
            confs_new = new double[confs.length + 1];
            confs_new[0] = 1;
            System.arraycopy(confs, 0, confs_new, 1, forms.length);
        }

        DependencyInstance instance =
            new DependencyInstance(forms_new, pos_new, deprels_new, heads_new, confs_new);

        // set up the course pos tags as just the first letter of the fine-grained ones
        String[] cpostags = new String[pos_new.length];
        cpostags[0] = "<root-CPOS>";
        for (int i = 1; i < pos_new.length; i++) {
            cpostags[i] = pos_new[i].substring(0, 1);
        }
        instance.cpostags = cpostags;

        // set up the lemmas as just the first 5 characters of the forms
        String[] lemmas = new String[forms_new.length];
        cpostags[0] = "<root-LEMMA>";
        for (int i = 1; i < forms_new.length; i++) {
            int formLength = forms_new[i].length();
            lemmas[i] = formLength > 5 ? forms_new[i].substring(0, 5) : forms_new[i];
        }
        instance.lemmas = lemmas;
        instance.feats = new String[0][0];

        return instance;
    }

    @Override
    protected boolean fileContainsLabels(String file) throws IOException {
        String line;
        try (BufferedReader in = new BufferedReader(new FileReader(file))) {
            in.readLine();
            in.readLine();
            in.readLine();
            if (confScores) {
                in.readLine();
            }
            line = in.readLine();
        }

        if (line.trim().length() > 0) {
            return true;
        } else {
            return false;
        }
    }
}