View Javadoc
1   /*
2    * reserved comment block
3    * DO NOT REMOVE OR ALTER!
4    */
5   /*
6    * Copyright 2001-2004 The Apache Software Foundation.
7    *
8    * Licensed under the Apache License, Version 2.0 (the "License");
9    * you may not use this file except in compliance with the License.
10   * 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, software
15   * distributed under the License is distributed on an "AS IS" BASIS,
16   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17   * See the License for the specific language governing permissions and
18   * limitations under the License.
19   */
20  /*
21   * $Id: BooleanExpr.java,v 1.2.4.1 2005/09/01 11:44:57 pvedula Exp $
22   */
23  
24  package com.sun.org.apache.xalan.internal.xsltc.compiler;
25  
26  import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
27  import com.sun.org.apache.bcel.internal.generic.GOTO;
28  import com.sun.org.apache.bcel.internal.generic.InstructionList;
29  import com.sun.org.apache.bcel.internal.generic.PUSH;
30  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
31  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
32  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
33  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
34  
35  /**
36   * This class implements inlined calls to the XSLT standard functions
37   * true() and false().
38   * @author Jacek Ambroziak
39   * @author Santiago Pericas-Geertsen
40   */
41  final class BooleanExpr extends Expression {
42      private boolean _value;
43  
44      public BooleanExpr(boolean value) {
45          _value = value;
46      }
47  
48      public Type typeCheck(SymbolTable stable) throws TypeCheckError {
49          _type = Type.Boolean;
50          return _type;
51      }
52  
53      public String toString() {
54          return _value ? "true()" : "false()";
55      }
56  
57      public boolean getValue() {
58          return _value;
59      }
60  
61      public boolean contextDependent() {
62          return false;
63      }
64  
65      public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
66          ConstantPoolGen cpg = classGen.getConstantPool();
67          InstructionList il = methodGen.getInstructionList();
68          il.append(new PUSH(cpg, _value));
69      }
70  
71      public void translateDesynthesized(ClassGenerator classGen,
72                                         MethodGenerator methodGen) {
73          final InstructionList il = methodGen.getInstructionList();
74          if (_value) {
75              il.append(NOP);     // true list falls through
76          }
77          else {
78              _falseList.add(il.append(new GOTO(null)));
79          }
80      }
81  }