hu.ppke.itk.nlpg.purepos.common.lemma.SuffixLemmaTransformation.java Source code

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Here is the source code for hu.ppke.itk.nlpg.purepos.common.lemma.SuffixLemmaTransformation.java

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/*******************************************************************************
 * Copyright (c) 2012 Gyrgy Orosz, Attila Novk.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser Public License v3
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/
 * 
 * This file is part of PurePos.
 * 
 * PurePos is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * PurePos is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser Public License for more details.
 * 
 * Contributors:
 *     Gyrgy Orosz - initial API and implementation
 ******************************************************************************/
package hu.ppke.itk.nlpg.purepos.common.lemma;

import org.apache.commons.lang3.tuple.Pair;

public class SuffixLemmaTransformation extends AbstractLemmaTransformation<Pair<String, Integer>> {

    private static final long serialVersionUID = 1160747425706872720L;

    public SuffixLemmaTransformation(String word, String lemma, Integer tag) {
        super(word, lemma, tag);
    }

    private static final int SHIFT = 100;

    @Override
    protected Pair<String, Integer> decode(String word, String stem, Integer tag) {
        int i;
        for (i = 0; i < word.length() && i < stem.length(); ++i) {
            if (word.charAt(i) != stem.charAt(i)) {
                break;
            }
        }
        String wordSuff = word.substring(i);
        int cutSize = wordSuff.length();
        String lemmaSuff = stem.substring(i);

        int code = SHIFT * tag + cutSize;

        return Pair.of(lemmaSuff, code);
    }

    @Override
    protected Pair<String, Integer> encode(String word, Pair<String, Integer> representation) {
        int tagCode = representation.getRight() / SHIFT;
        int cutSize = representation.getRight() % SHIFT;
        String add = representation.getLeft();
        String lemma = word.substring(0, word.length() - cutSize) + add;
        return Pair.of(lemma, tagCode);
    }

    @Override
    public int minimalCutLength() {
        return representation.getRight() % SHIFT;
    }

}