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1   /*
2    * Copyright  2000-2004 The Apache Software Foundation
3    *
4    *  Licensed under the Apache License, Version 2.0 (the "License"); 
5    *  you may not use this file except in compliance with the License.
6    *  You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   *  Unless required by applicable law or agreed to in writing, software
11   *  distributed under the License is distributed on an "AS IS" BASIS,
12   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   *  See the License for the specific language governing permissions and
14   *  limitations under the License. 
15   *
16   */
17  package org.apache.bcel.generic;
18  
19  /*** 
20   * DCONST - Push 0.0 or 1.0, other values cause an exception
21   *
22   * <PRE>Stack: ... -&gt; ..., </PRE>
23   *
24   * @version $Id: DCONST.java 386056 2006-03-15 11:31:56Z tcurdt $
25   * @author  <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
26   */
27  public class DCONST extends Instruction implements ConstantPushInstruction, TypedInstruction {
28  
29      private double value;
30  
31  
32      /***
33       * Empty constructor needed for the Class.newInstance() statement in
34       * Instruction.readInstruction(). Not to be used otherwise.
35       */
36      DCONST() {
37      }
38  
39  
40      public DCONST(double f) {
41          super(org.apache.bcel.Constants.DCONST_0, (short) 1);
42          if (f == 0.0) {
43              opcode = org.apache.bcel.Constants.DCONST_0;
44          } else if (f == 1.0) {
45              opcode = org.apache.bcel.Constants.DCONST_1;
46          } else {
47              throw new ClassGenException("DCONST can be used only for 0.0 and 1.0: " + f);
48          }
49          value = f;
50      }
51  
52  
53      public Number getValue() {
54          return new Double(value);
55      }
56  
57  
58      /*** @return Type.DOUBLE
59       */
60      public Type getType( ConstantPoolGen cp ) {
61          return Type.DOUBLE;
62      }
63  
64  
65      /***
66       * Call corresponding visitor method(s). The order is:
67       * Call visitor methods of implemented interfaces first, then
68       * call methods according to the class hierarchy in descending order,
69       * i.e., the most specific visitXXX() call comes last.
70       *
71       * @param v Visitor object
72       */
73      public void accept( Visitor v ) {
74          v.visitPushInstruction(this);
75          v.visitStackProducer(this);
76          v.visitTypedInstruction(this);
77          v.visitConstantPushInstruction(this);
78          v.visitDCONST(this);
79      }
80  }