code: /* LanguageTool, a natural language style checker
   * Copyright (C) 2008 Daniel Naber (http://www.danielnaber.de)
   * 
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library 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 General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
   * USA
   */
  
  package org.languagetool.tokenizers.br;
  
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  
  import org.languagetool.tokenizers.WordTokenizer;
  
  /**
   * @author Dominique Pelle
   */
  public class BretonWordTokenizer extends WordTokenizer {
  
    /**
     * Tokenizes just like WordTokenizer with the exception that "c’h"
     * is not split. "C’h" is considered as a letter in breton (trigraph)
     * and it occurs in many words.  So tokenizer should not split it.
     * Also split things like "n’eo" into 2 tokens only "n’" + "eo".
     * 
     * @param text Text to tokenize
     * @return List of tokens.
     *         Note: a special string ##BR_APOS## is used to replace apostrophes
     *         during tokenizing.
     */
    @Override
    public List<String> tokenize(String text) {
  
      // FIXME: this is a bit of a hacky way to tokenize.  It should work
      // but I should work on a more elegant way.
      String replaced = text.replaceAll("([Cc])['’‘ʼ]([Hh])", "$1\u0001\u0001BR@APOS\u0001\u0001$2")
          .replaceAll("(\\p{L})['’‘ʼ]", "$1\u0001\u0001BR@APOS\u0001\u0001 ");
  
      List<String> tokenList = super.tokenize(replaced);
      List<String> tokens = new ArrayList<>();
  
      // Put back apostrophes and remove spurious spaces.
      Iterator<String> itr = tokenList.iterator();
      while (itr.hasNext()) {
        String word = itr.next().replace("\u0001\u0001BR@APOS\u0001\u0001", "’");
        tokens.add(word);
        if (!word.equals("’") && word.endsWith("’")) {
          itr.next(); // Skip the next spurious white space.
        }
      }
      return tokens;
    }
  }
  