/**
 * boilerpipe
 *
 * Copyright (c) 2009, 2014 Christian Kohlschütter
 *
 * The author licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.kohlschutter.boilerpipe.util;

import java.util.regex.Pattern;

/**
 * Tokenizes text according to Unicode word boundaries and strips off non-word characters.
 */
public class UnicodeTokenizer {
  private static final Pattern PAT_WORD_BOUNDARY = Pattern.compile("\\b");
  private static final Pattern PAT_NOT_WORD_BOUNDARY = Pattern
      .compile("[\u2063]*([\\\"'\\.,\\!\\@\\-\\:\\;\\$\\?\\(\\)/])[\u2063]*");

  /**
   * Tokenizes the text and returns an array of tokens.
   * 
   * @param text The text
   * @return The tokens
   */
  public static String[] tokenize(final CharSequence text) {
    return PAT_NOT_WORD_BOUNDARY.matcher(PAT_WORD_BOUNDARY.matcher(text).replaceAll("\u2063"))
        .replaceAll("$1").replaceAll("[ \u2063]+", " ").trim().split("[ ]+");
  }
}
