org.languagetool.rules.en.GoogleStyleWordTokenizer Maven / Gradle / Ivy
/* LanguageTool, a natural language style checker
* Copyright (C) 2014 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.rules.en;
import org.languagetool.tokenizers.WordTokenizer;
import java.util.*;
/**
* Tokenize sentences to tokens like Google does for its ngram index. Note: there
* doesn't seem to be official documentation about the way Google tokenizes there,
* so this is just an approximation.
* @since 3.2
*/
public class GoogleStyleWordTokenizer extends WordTokenizer {
@Override
public String getTokenizingCharacters() {
return super.getTokenizingCharacters() + "-";
}
@Override
public List tokenize(String text) {
List tokens = super.tokenize(text);
String prev = null;
Stack l = new Stack<>();
for (String token : tokens) {
if ("'".equals(prev)) {
// TODO: add more cases if needed:
if (token.equals("m")) {
l.pop();
l.push("'m");
} else if (token.equals("re")) {
l.pop();
l.push("'re");
} else if (token.equals("ve")) {
l.pop();
l.push("'ve");
} else if (token.equals("ll")) {
l.pop();
l.push("'ll");
} else {
l.push(token);
}
} else {
l.push(token);
}
prev = token;
}
return l;
}
}