pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / analyzers / smartcn / src / java / org / apache / lucene / analysis / cn / smart / hhmm / SegTokenFilter.java

diff --git a/lucene-java-3.5.0/lucene/contrib/analyzers/smartcn/src/java/org/apache/lucene/analysis/cn/smart/hhmm/SegTokenFilter.java b/lucene-java-3.5.0/lucene/contrib/analyzers/smartcn/src/java/org/apache/lucene/analysis/cn/smart/hhmm/SegTokenFilter.java
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+++ b/lucene-java-3.5.0/lucene/contrib/analyzers/smartcn/src/java/org/apache/lucene/analysis/cn/smart/hhmm/SegTokenFilter.java
@@ -0,0 +1,68 @@
+/**
+ * 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.cn.smart.hhmm;
+
+import org.apache.lucene.analysis.cn.smart.Utility;
+import org.apache.lucene.analysis.cn.smart.WordType;
+
+/**
+ * <p>
+ * Filters a {@link SegToken} by converting full-width latin to half-width, then lowercasing latin.
+ * Additionally, all punctuation is converted into {@link Utility#COMMON_DELIMITER}
+ * </p>
+ * @lucene.experimental
+ */
+public class SegTokenFilter {
+
+  /**
+   * Filter an input {@link SegToken}
+   * <p>
+   * Full-width latin will be converted to half-width, then all latin will be lowercased.
+   * All punctuation is converted into {@link Utility#COMMON_DELIMITER}
+   * </p>
+   * 
+   * @param token input {@link SegToken}
+   * @return normalized {@link SegToken}
+   */
+  public SegToken filter(SegToken token) {
+    switch (token.wordType) {
+      case WordType.FULLWIDTH_NUMBER:
+      case WordType.FULLWIDTH_STRING: /* first convert full-width -> half-width */
+        for (int i = 0; i < token.charArray.length; i++) {
+          if (token.charArray[i] >= 0xFF10)
+            token.charArray[i] -= 0xFEE0;
+
+          if (token.charArray[i] >= 0x0041 && token.charArray[i] <= 0x005A) /* lowercase latin */
+            token.charArray[i] += 0x0020;
+        }
+        break;
+      case WordType.STRING:
+        for (int i = 0; i < token.charArray.length; i++) {
+          if (token.charArray[i] >= 0x0041 && token.charArray[i] <= 0x005A) /* lowercase latin */
+            token.charArray[i] += 0x0020;
+        }
+        break;
+      case WordType.DELIMITER: /* convert all punctuation to Utility.COMMON_DELIMITER */
+        token.charArray = Utility.COMMON_DELIMITER;
+        break;
+      default:
+        break;
+    }
+    return token;
+  }
+}