lucene/analysis/common/src/java/org/apache/lucene/analysis/te/TeluguStemmer.java

/*
 * 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 org.apache.lucene.analysis.te;

import static org.apache.lucene.analysis.util.StemmerUtil.endsWith;

/**
 * Stemmer for Telugu.
 *
 * @since 9.0.0
 */
public class TeluguStemmer {
  public int stem(char buffer[], int len) {
    // 4
    if ((len > 5) && (endsWith(buffer, len, "ళ్ళు") || endsWith(buffer, len, "డ్లు")))
      return len - 4;

    // 2
    if ((len > 3)
        && (endsWith(buffer, len, "డు")
            || endsWith(buffer, len, "ము")
            || endsWith(buffer, len, "వు")
            || endsWith(buffer, len, "లు")
            || endsWith(buffer, len, "ని")
            || endsWith(buffer, len, "ను")
            || endsWith(buffer, len, "చే")
            || endsWith(buffer, len, "కై")
            || endsWith(buffer, len, "లో")
            || endsWith(buffer, len, "డు")
            || endsWith(buffer, len, "ది")
            || endsWith(buffer, len, "కి")
            || endsWith(buffer, len, "సు")
            || endsWith(buffer, len, "వై")
            || endsWith(buffer, len, "పై"))) return len - 2;

    // 1
    if ((len > 2)
        && (endsWith(buffer, len, "ి")
            || endsWith(buffer, len, "ీ")
            || endsWith(buffer, len, "ు")
            || endsWith(buffer, len, "ూ")
            || endsWith(buffer, len, "ె")
            || endsWith(buffer, len, "ే")
            || endsWith(buffer, len, "ొ")
            || endsWith(buffer, len, "ో")
            || endsWith(buffer, len, "ా"))) return len - 1;

    return len;
  }
}