| /* |
| * 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.queryparser.flexible.core.util; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import org.apache.lucene.queryparser.flexible.core.QueryNodeError; |
| import org.apache.lucene.queryparser.flexible.core.nodes.AndQueryNode; |
| import org.apache.lucene.queryparser.flexible.core.nodes.QueryNode; |
| |
| /** Allow joining 2 QueryNode Trees, into one. */ |
| public final class QueryNodeOperation { |
| private QueryNodeOperation() { |
| // Exists only to defeat instantiation. |
| } |
| |
| private enum ANDOperation { |
| BOTH, |
| Q1, |
| Q2, |
| NONE |
| } |
| |
| /** |
| * perform a logical and of 2 QueryNode trees. if q1 and q2 are ANDQueryNode nodes it uses head |
| * Node from q1 and adds the children of q2 to q1 if q1 is a AND node and q2 is not, add q2 as a |
| * child of the head node of q1 if q2 is a AND node and q1 is not, add q1 as a child of the head |
| * node of q2 if q1 and q2 are not ANDQueryNode nodes, create a AND node and make q1 and q2 |
| * children of that node if q1 or q2 is null it returns the not null node if q1 = q2 = null it |
| * returns null |
| */ |
| public static final QueryNode logicalAnd(QueryNode q1, QueryNode q2) { |
| if (q1 == null) return q2; |
| if (q2 == null) return q1; |
| |
| ANDOperation op = null; |
| if (q1 instanceof AndQueryNode && q2 instanceof AndQueryNode) op = ANDOperation.BOTH; |
| else if (q1 instanceof AndQueryNode) op = ANDOperation.Q1; |
| else if (q2 instanceof AndQueryNode) op = ANDOperation.Q2; |
| else op = ANDOperation.NONE; |
| |
| try { |
| QueryNode result = null; |
| switch (op) { |
| case NONE: |
| List<QueryNode> children = new ArrayList<>(); |
| children.add(q1.cloneTree()); |
| children.add(q2.cloneTree()); |
| result = new AndQueryNode(children); |
| return result; |
| case Q1: |
| result = q1.cloneTree(); |
| result.add(q2.cloneTree()); |
| return result; |
| case Q2: |
| result = q2.cloneTree(); |
| result.add(q1.cloneTree()); |
| return result; |
| case BOTH: |
| result = q1.cloneTree(); |
| result.add(q2.cloneTree().getChildren()); |
| return result; |
| } |
| } catch (CloneNotSupportedException e) { |
| throw new QueryNodeError(e); |
| } |
| |
| return null; |
| } |
| } |