GPower


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  import org.lsmp.djep.groupJep.interfaces.*;
12  
13  import java.util.*;
14  import org.nfunk.jep.*;
15  /**
16   * @author Rich Morris
17   * Created on 05-Mar-2004
18   */
19  public class GPower extends PostfixMathCommand {
20      /** null if power not implemented */
21      private HasPowerI group=null;
22      /**
23       * 
24       */
25      private GPower() {  }
26      public GPower(GroupI group)
27      {
28          numberOfParameters = 2;
29          if(group instanceof HasPowerI)
30              this.group = (HasPowerI) group;
31      }
32  
33      /**
34       * Calculates the result of applying the "+" operator to the arguments from
35       * the stack and pushes it back on the stack.
36       */
37      public void run(Stack stack) throws ParseException {
38          checkStack(stack);// check the stack
39          Object   exponant = stack.pop();
40          Object   param = stack.pop();
41          Object   res = pow(param, exponant);
42          stack.push(res);
43          return;
44      }
45  
46      public Object   pow(Object   param1, Object   param2) throws ParseException {
47          if(group==null) throw new ParseException("Power not implemented for this group.");
48          if (param1 instanceof Number  ) {
49              if (param2 instanceof Number  ) {
50                  return group.pow((Number  )param1, (Number  )param2);
51              }
52          }
53          
54          throw new ParseException("Invalid parameter type");
55      }
56  }
57
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags