pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / queryparser / src / java / org / apache / lucene / queryParser / core / nodes / BoostQueryNode.java

diff --git a/lucene-java-3.5.0/lucene/contrib/queryparser/src/java/org/apache/lucene/queryParser/core/nodes/BoostQueryNode.java b/lucene-java-3.5.0/lucene/contrib/queryparser/src/java/org/apache/lucene/queryParser/core/nodes/BoostQueryNode.java
new file mode 100644 (file)
index 0000000..b337be4
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+++ b/lucene-java-3.5.0/lucene/contrib/queryparser/src/java/org/apache/lucene/queryParser/core/nodes/BoostQueryNode.java
@@ -0,0 +1,124 @@
+package org.apache.lucene.queryParser.core.nodes;
+
+/**
+ * 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.util.List;
+
+import org.apache.lucene.messages.MessageImpl;
+import org.apache.lucene.queryParser.core.QueryNodeError;
+import org.apache.lucene.queryParser.core.QueryNodeException;
+import org.apache.lucene.queryParser.core.messages.QueryParserMessages;
+import org.apache.lucene.queryParser.core.parser.EscapeQuerySyntax;
+
+/**
+ * A {@link BoostQueryNode} boosts the QueryNode tree which is under this node.
+ * So, it must only and always have one child.
+ * 
+ * The boost value may vary from 0.0 to 1.0.
+ * 
+ */
+public class BoostQueryNode extends QueryNodeImpl {
+
+  private static final long serialVersionUID = -3929082630855807593L;
+
+  private float value = 0;
+
+  /**
+   * Constructs a boost node
+   * 
+   * @param query
+   *          the query to be boosted
+   * @param value
+   *          the boost value, it may vary from 0.0 to 1.0
+   * 
+   * @throws QueryNodeException
+   */
+  public BoostQueryNode(QueryNode query, float value) throws QueryNodeException {
+    if (query == null) {
+      throw new QueryNodeError(new MessageImpl(
+          QueryParserMessages.NODE_ACTION_NOT_SUPPORTED, "query", "null"));
+    }
+
+    this.value = value;
+    setLeaf(false);
+    allocate();
+    add(query);
+  }
+
+  /**
+   * Returns the single child which this node boosts.
+   * 
+   * @return the single child which this node boosts
+   */
+  public QueryNode getChild() {
+    List<QueryNode> children = getChildren();
+
+    if (children == null || children.size() == 0) {
+      return null;
+    }
+
+    return children.get(0);
+
+  }
+
+  /**
+   * Returns the boost value. It may vary from 0.0 to 1.0.
+   * 
+   * @return the boost value
+   */
+  public float getValue() {
+    return this.value;
+  }
+
+  /**
+   * Returns the boost value parsed to a string.
+   * 
+   * @return the parsed value
+   */
+  private CharSequence getValueString() {
+    Float f = Float.valueOf(this.value);
+    if (f == f.longValue())
+      return "" + f.longValue();
+    else
+      return "" + f;
+
+  }
+
+  @Override
+  public String toString() {
+    return "<boost value='" + getValueString() + "'>" + "\n"
+        + getChild().toString() + "\n</boost>";
+  }
+
+  public CharSequence toQueryString(EscapeQuerySyntax escapeSyntaxParser) {
+    if (getChild() == null)
+      return "";
+    return getChild().toQueryString(escapeSyntaxParser) + "^"
+        + getValueString();
+  }
+
+  @Override
+  public QueryNode cloneTree() throws CloneNotSupportedException {
+    BoostQueryNode clone = (BoostQueryNode) super.cloneTree();
+
+    clone.value = this.value;
+
+    return clone;
+  }
+
+}