View Javadoc
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  
18  package org.apache.commons.jxpath.ri.compiler;
19  
20  import org.apache.commons.jxpath.ri.EvalContext;
21  import org.apache.commons.jxpath.ri.axes.UnionContext;
22  
23  /**
24   * Implementation of {@link Expression} for the operation "|".
25   */
26  public class CoreOperationUnion extends CoreOperation {
27  
28      /**
29       * Constructs a new CoreOperationUnion.
30       *
31       * @param args Expression[]
32       */
33      public CoreOperationUnion(final Expression[] args) {
34          super(args);
35      }
36  
37      @Override
38      public Object computeValue(final EvalContext context) {
39          final EvalContext[] argCtxs = new EvalContext[args.length];
40          for (int i = 0; i < args.length; i++) {
41              final Object value = args[i].compute(context);
42              if (value instanceof EvalContext) {
43                  argCtxs[i] = (EvalContext) value;
44              } else {
45                  argCtxs[i] = context.getRootContext().getConstantContext(value);
46              }
47          }
48          return new UnionContext(context.getRootContext(), argCtxs);
49      }
50  
51      @Override
52      protected int getPrecedence() {
53          return UNION_PRECEDENCE;
54      }
55  
56      @Override
57      public String getSymbol() {
58          return "|";
59      }
60  
61      @Override
62      protected boolean isSymmetric() {
63          return true;
64      }
65  }