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1   package org.apache.velocity.runtime.parser.node;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *   http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.    
20   */
21  
22  import org.apache.velocity.context.InternalContextAdapter;
23  import org.apache.velocity.runtime.parser.Parser;
24  
25  /**
26   * Handles number addition of nodes.<br><br>
27   *
28   * Please look at the Parser.jjt file which is
29   * what controls the generation of this class.
30   *
31   * @author <a href="mailto:wglass@forio.com">Will Glass-Husain</a>
32   * @author <a href="mailto:pero@antaramusic.de">Peter Romianowski</a>
33   * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
34   * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
35   * @version $Id: ASTAddNode.java 712887 2008-11-11 00:27:50Z nbubna $
36   */
37  public class ASTAddNode extends ASTMathNode
38  {
39      /**
40       * @param id
41       */
42      public ASTAddNode(int id)
43      {
44          super(id);
45      }
46  
47      /**
48       * @param p
49       * @param id
50       */
51      public ASTAddNode(Parser p, int id)
52      {
53          super(p, id);
54      }
55  
56      //@Override
57      protected Object handleSpecial(Object left, Object right, InternalContextAdapter context)
58      {
59          /*
60           * shall we try for strings?
61           */
62          if (left instanceof String || right instanceof String)
63          {
64              if (left == null)
65              {
66                  left = jjtGetChild(0).literal();
67              }
68              else if (right == null)
69              {
70                  right = jjtGetChild(1).literal();
71              }
72              return left.toString().concat(right.toString());
73          }
74          return null;
75      }
76  
77      public Number perform(Number left, Number right, InternalContextAdapter context)
78      {
79          return MathUtils.add(left, right);
80      }
81  
82  }
83  
84  
85  
86