BooleanStateStack


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14   * Copyright (C) 2006 Mirko Stocker <me@misto.ch>
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28  
29  package org.jruby.ast.visitor.rewriter.utils;
30  
31  import java.util.EmptyStackException  ;
32  import java.util.Stack  ;
33  
34  public class BooleanStateStack {
35      
36      private final Stack   states = new Stack  ();
37      private final boolean defaultValue;
38      
39  
40      public BooleanStateStack(boolean b, boolean defaultValue) {
41          set(b);
42          this.defaultValue = defaultValue;
43      }
44      
45      public void set(boolean b) {
46          states.push(Boolean.valueOf(b));
47      }
48      
49      public void revert() {
50          states.pop();
51      }
52      
53      public boolean isTrue() {
54          try {
55              return ((Boolean  ) states.peek()).booleanValue();
56          } catch (EmptyStackException   e) {
57              return defaultValue;
58          }
59      }
60  }
61
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