pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / src / java / org / apache / lucene / search / TermCollectingRewrite.java

diff --git a/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/TermCollectingRewrite.java b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/TermCollectingRewrite.java
new file mode 100644 (file)
index 0000000..fffad8e
--- /dev/null
+++ b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/TermCollectingRewrite.java
@@ -0,0 +1,50 @@
+package org.apache.lucene.search;
+
+/**
+ * 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.
+ */
+
+import java.io.IOException;
+
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.index.Term;
+
+abstract class TermCollectingRewrite<Q extends Query> extends MultiTermQuery.RewriteMethod {
+  
+  /** Return a suitable top-level Query for holding all expanded terms. */
+  protected abstract Q getTopLevelQuery() throws IOException;
+  
+  /** Add a MultiTermQuery term to the top-level query */
+  protected abstract void addClause(Q topLevel, Term term, float boost) throws IOException;
+  
+  protected final void collectTerms(IndexReader reader, MultiTermQuery query, TermCollector collector) throws IOException {
+    final FilteredTermEnum enumerator = query.getEnum(reader);
+    try {
+      do {
+        final Term t = enumerator.term();
+        if (t == null || !collector.collect(t, enumerator.difference()))
+          break;
+      } while (enumerator.next());    
+    } finally {
+      enumerator.close();
+    }
+  }
+  
+  protected interface TermCollector {
+    /** return false to stop collecting */
+    boolean collect(Term t, float boost) throws IOException;
+  }
+}