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package org.apache.lucene.queryParser.standard.processors;
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership.
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* The ASF licenses this file to You under the Apache License, Version 2.0
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* (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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* http://www.apache.org/licenses/LICENSE-2.0
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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import java.util.List;
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import org.apache.lucene.queryParser.core.QueryNodeException;
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import org.apache.lucene.queryParser.core.nodes.BooleanQueryNode;
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import org.apache.lucene.queryParser.core.nodes.ModifierQueryNode;
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import org.apache.lucene.queryParser.core.nodes.QueryNode;
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import org.apache.lucene.queryParser.core.nodes.ModifierQueryNode.Modifier;
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import org.apache.lucene.queryParser.core.processors.QueryNodeProcessorImpl;
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import org.apache.lucene.queryParser.standard.nodes.BooleanModifierNode;
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* This processor removes every {@link BooleanQueryNode} that contains only one
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* child and returns this child. If this child is {@link ModifierQueryNode} that
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* was defined by the user. A modifier is not defined by the user when it's a
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* {@link BooleanModifierNode} <br/>
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* @see ModifierQueryNode
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public class BooleanSingleChildOptimizationQueryNodeProcessor extends
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QueryNodeProcessorImpl {
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public BooleanSingleChildOptimizationQueryNodeProcessor() {
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protected QueryNode postProcessNode(QueryNode node) throws QueryNodeException {
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if (node instanceof BooleanQueryNode) {
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List<QueryNode> children = node.getChildren();
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if (children != null && children.size() == 1) {
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QueryNode child = children.get(0);
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if (child instanceof ModifierQueryNode) {
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ModifierQueryNode modNode = (ModifierQueryNode) child;
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if (modNode instanceof BooleanModifierNode
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|| modNode.getModifier() == Modifier.MOD_NONE) {
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protected QueryNode preProcessNode(QueryNode node) throws QueryNodeException {
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protected List<QueryNode> setChildrenOrder(List<QueryNode> children)
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throws QueryNodeException {