GAdd


1   /* @author rich
2    * Created on 05-Mar-2004
3    *
4    * This code is covered by a Creative Commons
5    * Attribution, Non Commercial, Share Alike license
6    * <a HREF="http://creativecommons.org/licenses/by-nc-sa/1.0">License</a>
7    */
8   package org.lsmp.djep.groupJep.function;
9   import org.nfunk.jep.function.*;
10  import org.lsmp.djep.groupJep.*;
11  
12  import java.util.*;
13  import org.nfunk.jep.*;
14  /**
15   * @author Rich Morris
16   * Created on 05-Mar-2004
17   */
18  public class GAdd extends PostfixMathCommand {
19      private GroupI group;
20      /**
21       * 
22       */
23      private GAdd() {    }
24      public GAdd(GroupI group)
25      {
26          numberOfParameters = -1;
27          this.group = group;
28      }
29  
30      /**
31       * Calculates the result of applying the "+" operator to the arguments from
32       * the stack and pushes it back on the stack.
33       */
34      public void run(Stack stack) throws ParseException {
35          checkStack(stack);// check the stack
36          
37          Object   sum = stack.pop();
38          Object   param;
39          int i = 1;
40          
41          // repeat summation for each one of the current parameters
42          while (i < curNumberOfParameters) {
43              // get the parameter from the stack
44              param = stack.pop();
45              // add it to the sum (order is important for String arguments)
46              sum = add(param, sum);
47              i++;
48          }
49          stack.push(sum);
50          return;
51      }
52  
53      public Object   add(Object   param1, Object   param2) throws ParseException {
54          if (param1 instanceof Number  ) {
55              if (param2 instanceof Number  ) {
56                  return group.add((Number  )param1, (Number  )param2);
57              }
58          }
59          
60          throw new ParseException("Invalid parameter type");
61      }
62  }
63
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