--- /dev/null
+package org.apache.lucene.queryParser.standard.processors;
+
+/**
+ * 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.queryParser.core.QueryNodeException;
+import org.apache.lucene.queryParser.core.nodes.BooleanQueryNode;
+import org.apache.lucene.queryParser.core.nodes.ModifierQueryNode;
+import org.apache.lucene.queryParser.core.nodes.QueryNode;
+import org.apache.lucene.queryParser.core.nodes.ModifierQueryNode.Modifier;
+import org.apache.lucene.queryParser.core.processors.QueryNodeProcessorImpl;
+import org.apache.lucene.queryParser.standard.nodes.BooleanModifierNode;
+
+/**
+ * This processor removes every {@link BooleanQueryNode} that contains only one
+ * child and returns this child. If this child is {@link ModifierQueryNode} that
+ * was defined by the user. A modifier is not defined by the user when it's a
+ * {@link BooleanModifierNode} <br/>
+ *
+ * @see ModifierQueryNode
+ */
+public class BooleanSingleChildOptimizationQueryNodeProcessor extends
+ QueryNodeProcessorImpl {
+
+ public BooleanSingleChildOptimizationQueryNodeProcessor() {
+ // empty constructor
+ }
+
+ @Override
+ protected QueryNode postProcessNode(QueryNode node) throws QueryNodeException {
+
+ if (node instanceof BooleanQueryNode) {
+ List<QueryNode> children = node.getChildren();
+
+ if (children != null && children.size() == 1) {
+ QueryNode child = children.get(0);
+
+ if (child instanceof ModifierQueryNode) {
+ ModifierQueryNode modNode = (ModifierQueryNode) child;
+
+ if (modNode instanceof BooleanModifierNode
+ || modNode.getModifier() == Modifier.MOD_NONE) {
+
+ return child;
+
+ }
+
+ } else {
+ return child;
+ }
+
+ }
+
+ }
+
+ return node;
+
+ }
+
+ @Override
+ protected QueryNode preProcessNode(QueryNode node) throws QueryNodeException {
+
+ return node;
+
+ }
+
+ @Override
+ protected List<QueryNode> setChildrenOrder(List<QueryNode> children)
+ throws QueryNodeException {
+
+ return children;
+
+ }
+
+}