scale.clef.expr
Class NotOp

java.lang.Object
  extended by scale.common.Root
      extended by scale.clef.Node
          extended by scale.clef.expr.Expression
              extended by scale.clef.expr.MonadicOp
                  extended by scale.clef.expr.NotOp
All Implemented Interfaces:
AnnotationInterface, DisplayNode

public class NotOp
extends MonadicOp

A Class representing a boolean not operation.

$Id: NotOp.java,v 1.29 2005-02-07 21:28:00 burrill Exp $

Copyright 2005 by the Scale Compiler Group,
Department of Computer Science
University of Massachusetts,
Amherst MA. 01003, USA
All Rights Reserved.


Constructor Summary
NotOp(Type type, Expression e)
           
 
Method Summary
 Literal getConstantValue()
          Return the constant value of the expression.
 boolean hasTrueFalseResult()
          Return true if the result of the expression is either true (1) or false (0).
 void visit(Predicate p)
          Process a node by calling its associated routine.
 
Methods inherited from class scale.clef.expr.MonadicOp
containsDeclaration, equivalent, getChild, getDeclList, getExpr, isSimpleOp, numChildren, setExpr
 
Methods inherited from class scale.clef.expr.Expression
canonical, getCoreType, getDisplayColorHint, getDisplayLabel, getDisplayShapeHint, getPointedToCore, getType, setType, toStringSpecial
 
Methods inherited from class scale.clef.Node
getDecl, getSourceLineNumber, setAnnotationLevel, setReportLevel, setSourceLineNumber, toString, toString, toStringChildren
 
Methods inherited from class scale.common.Root
addAnnotation, allAnnotations, allMatchingAnnotations, getAnnotation, getDisplayName, getDisplayString, getNodeCount, getNodeID, hasAnnotation, hasEqualAnnotation, hashCode, removeAnnotation, removeAnnotations, toStringAnnotations, toStringClass, trace, trace, trace
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Constructor Detail

NotOp

public NotOp(Type type,
             Expression e)
Method Detail

visit

public void visit(Predicate p)
Description copied from class: Node
Process a node by calling its associated routine. See the "visitor" design pattern in Design Patterns: Elements of Reusable Object-Oriented Software by E. Gamma, et al, Addison Wesley, ISBN 0-201-63361-2.

Each class has a visit(Predicate p) method. For example, in class ABC:

   public void visit(Predicate p)
   {
     p.visitABC(this);
   }
 
and the class that implements Predicate has a method
   public void visitABC(Node n)
   {
     ABC a = (ABC) n;
     ...
   }
 
Thus, the class that implements Predicate can call
   n.visit(this);
 
where n is a Node sub-class without determining which specific sub-class n is. The visit pattern basically avoids implementing a large switch statement or defining different methods in each class for some purpose.

Overrides:
visit in class MonadicOp
See Also:
Predicate

getConstantValue

public Literal getConstantValue()
Return the constant value of the expression.

Overrides:
getConstantValue in class Expression
See Also:
Lattice

hasTrueFalseResult

public boolean hasTrueFalseResult()
Return true if the result of the expression is either true (1) or false (0).

Overrides:
hasTrueFalseResult in class Expression