content: package org.apache.lucene.analysis.util;
  
  /**
   * 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.
   */
  
  /** Some commonly-used stemming functions */
  public class StemmerUtil {
    /**
     * Returns true if the character array starts with the suffix.
     * 
     * @param s Input Buffer
     * @param len length of input buffer
     * @param prefix Prefix string to test
     * @return true if <code>s</code> starts with <code>prefix</code>
     */
    public static boolean startsWith(char s[], int len, String prefix) {
      final int prefixLen = prefix.length();
      if (prefixLen > len)
        return false;
      for (int i = 0; i < prefixLen; i++)
        if (s[i] != prefix.charAt(i)) 
          return false;
      return true;
    }
    
    /**
     * Returns true if the character array ends with the suffix.
     * 
     * @param s Input Buffer
     * @param len length of input buffer
     * @param suffix Suffix string to test
     * @return true if <code>s</code> ends with <code>suffix</code>
     */
    public static boolean endsWith(char s[], int len, String suffix) {
      final int suffixLen = suffix.length();
      if (suffixLen > len)
        return false;
      for (int i = suffixLen - 1; i >= 0; i--)
        if (s[len -(suffixLen - i)] != suffix.charAt(i))
          return false;
      
      return true;
    }
    
    /**
     * Returns true if the character array ends with the suffix.
     * 
     * @param s Input Buffer
     * @param len length of input buffer
     * @param suffix Suffix string to test
     * @return true if <code>s</code> ends with <code>suffix</code>
     */
    public static boolean endsWith(char s[], int len, char suffix[]) {
      final int suffixLen = suffix.length;
      if (suffixLen > len)
        return false;
      for (int i = suffixLen - 1; i >= 0; i--)
        if (s[len -(suffixLen - i)] != suffix[i])
          return false;
      
      return true;
    }
    
    /**
     * Delete a character in-place
     * 
     * @param s Input Buffer
     * @param pos Position of character to delete
     * @param len length of input buffer
     * @return length of input buffer after deletion
     */
    public static int delete(char s[], int pos, int len) {
      if (pos < len) 
        System.arraycopy(s, pos + 1, s, pos, len - pos - 1);
      
      return len - 1;
    }
    
    /**
     * Delete n characters in-place
     * 
     * @param s Input Buffer
     * @param pos Position of character to delete
     * @param len Length of input buffer
     * @param nChars number of characters to delete
     * @return length of input buffer after deletion
     */
    public static int deleteN(char s[], int pos, int len, int nChars) {
      // TODO: speed up, this is silly
      for (int i = 0; i < nChars; i++)
        len = delete(s, pos, len);
      return len;
    }
  }
  