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 * 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
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 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
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 * See the License for the specific language governing permissions and
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package org.apache.lucene.analysis.util;


Some commonly-used stemming functions
@lucene.internal
/** * Some commonly-used stemming functions * * @lucene.internal */
public class StemmerUtil {
no instance
/** no instance */
private StemmerUtil() {}
Returns true if the character array starts with the suffix.
Params:
  • s – Input Buffer
  • len – length of input buffer
  • prefix – Prefix string to test
Returns:true if s starts with prefix
/** * 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.
Params:
  • s – Input Buffer
  • len – length of input buffer
  • suffix – Suffix string to test
Returns:true if s ends with suffix
/** * 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.
Params:
  • s – Input Buffer
  • len – length of input buffer
  • suffix – Suffix string to test
Returns:true if s ends with suffix
/** * 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
Params:
  • s – Input Buffer
  • pos – Position of character to delete
  • len – length of input buffer
Returns:length of input buffer after deletion
/** * 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) { assert pos < len; if (pos < len - 1) { // don't arraycopy if asked to delete last character System.arraycopy(s, pos + 1, s, pos, len - pos - 1); } return len - 1; }
Delete n characters in-place
Params:
  • s – Input Buffer
  • pos – Position of character to delete
  • len – Length of input buffer
  • nChars – number of characters to delete
Returns:length of input buffer after deletion
/** * 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) { assert pos + nChars <= len; if (pos + nChars < len) { // don't arraycopy if asked to delete the last characters System.arraycopy(s, pos + nChars, s, pos, len - pos - nChars); } return len - nChars; } }