opennlp.tools.util.featuregen.BrownTokenClasses Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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 opennlp.tools.util.featuregen;
import java.util.ArrayList;
import java.util.List;
/**
* Obtain the paths listed in the pathLengths array from the Brown class.
* This class is not to be instantiated.
*
*/
public class BrownTokenClasses {
public static final int[] pathLengths = { 4, 6, 10, 20 };
/**
* It provides a list containing the pathLengths for a token if found
* in the Map:token,BrownClass.
*
* @param token the token to be looked up in the brown clustering map
* @param brownLexicon the Brown clustering map
* @return the list of the paths for a token
*/
public static List getWordClasses(String token, BrownCluster brownLexicon) {
if (brownLexicon.lookupToken(token) == null) {
return new ArrayList<>(0);
} else {
String brownClass = brownLexicon.lookupToken(token);
List pathLengthsList = new ArrayList<>();
pathLengthsList.add(brownClass.substring(0, Math.min(brownClass.length(), pathLengths[0])));
for (int i = 1; i < pathLengths.length; i++) {
if (pathLengths[i - 1] < brownClass.length()) {
pathLengthsList.add(brownClass.substring(0,
Math.min(brownClass.length(), pathLengths[i])));
}
}
return pathLengthsList;
}
}
}