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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.jxpath.ri.compiler;
18  
19  import org.apache.commons.jxpath.ri.EvalContext;
20  import org.apache.commons.jxpath.ri.axes.UnionContext;
21  
22  /**
23   * Implementation of {@link Expression} for the operation "|".
24   *
25   * @author Dmitri Plotnikov
26   * @version $Revision: 652845 $ $Date: 2008-05-02 13:46:46 -0400 (Fri, 02 May 2008) $
27   */
28  public class CoreOperationUnion extends CoreOperation {
29  
30      /**
31       * Create a new CoreOperationUnion.
32       * @param args Expression[]
33       */
34      public CoreOperationUnion(Expression[] args) {
35          super(args);
36      }
37  
38      public Object computeValue(EvalContext context) {
39          EvalContext[] argCtxs = new EvalContext[args.length];
40          for (int i = 0; i < args.length; i++) {
41              Object value = args[i].compute(context);
42              if (value instanceof EvalContext) {
43                  argCtxs[i] = (EvalContext) value;
44              }
45              else {
46                  argCtxs[i] = context.getRootContext().getConstantContext(value);
47              }
48          }
49          return new UnionContext(context.getRootContext(), argCtxs);
50      }
51  
52      protected int getPrecedence() {
53          return UNION_PRECEDENCE;
54      }
55  
56      protected boolean isSymmetric() {
57          return true;
58      }
59  
60      public String getSymbol() {
61          return "|";
62      }
63  }