pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / analyzers / common / src / java / org / apache / lucene / analysis / util / StemmerUtil.java

diff --git a/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/util/StemmerUtil.java b/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/util/StemmerUtil.java
new file mode 100644 (file)
index 0000000..7aceadf
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+++ b/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/util/StemmerUtil.java
@@ -0,0 +1,108 @@
+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;
+  }
+}