scale.clef.expr
Class BooleanLiteral

java.lang.Object
  scale.common.Root
      scale.clef.Node
          scale.clef.expr.Expression
              scale.clef.expr.Literal
                  scale.clef.expr.BooleanLiteral

All Implemented Interfaces:

AnnotationInterface, DisplayNode

public class BooleanLiteral
extends Literal

A class which represents a boolean literal value.

$Id: BooleanLiteral.java,v 1.31 2007-03-21 13:31:53 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

BooleanLiteral(Type t, boolean v)

Method Summary

long	canonical() Return a unique value representing this particular expression.
boolean	equivalent(java.lang.Object exp) Return true if the two expressions are equivalent.
int	executionCostEstimate() Return a relative cost estimate for executing the expression.
boolean	getBooleanValue() Return the boolean value of the literal.
java.lang.String	getGenericValue() Get the string version of the literal using C syntax with symbols 'true' and 'false'.
boolean	hasTrueFalseResult() Return true if the result of the expression is either true (1) or false (0).
boolean	isZero() Return true if the value of this literal is known to be false.
protected void	setValue(boolean value) Specify the boolean value of the literal.
java.lang.String	toStringSpecial() This method allows sub-classes to provide class specific stuff to the string.
void	visit(Predicate p) Process a node by calling its associated routine.

Methods inherited from class scale.clef.expr.Literal

findCoefficient, formatRealValue, getConstantValue, getCount, getDeclList, getDisplayLabel, getElement, isOne, linearity

Methods inherited from class scale.clef.expr.Expression

containsDeclaration, getCoreType, getDisplayColorHint, getDisplayShapeHint, getPointedToCore, getType, isSimpleOp, setType

Methods inherited from class scale.clef.Node

getChild, getDecl, getSourceLineNumber, numChildren, 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

BooleanLiteral

public BooleanLiteral(Type t,
                      boolean v)

Method Detail

equivalent

public boolean equivalent(java.lang.Object exp)

Return true if the two expressions are equivalent.

Overrides:

equivalent in class Expression

toStringSpecial

public java.lang.String toStringSpecial()

Description copied from class: Node

This method allows sub-classes to provide class specific stuff to the string.

Overrides:

toStringSpecial in class Expression

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 Literal

See Also:

Predicate

getGenericValue

public final java.lang.String getGenericValue()

Get the string version of the literal using C syntax with symbols 'true' and 'false'.

Overrides:

getGenericValue in class Literal

Returns:

a String already converted for display using C syntax.

getBooleanValue

public boolean getBooleanValue()

Return the boolean value of the literal.

setValue

protected final void setValue(boolean value)

Specify the boolean value of the literal.

canonical

public long canonical()

Return a unique value representing this particular expression.

Overrides:

canonical in class Expression

executionCostEstimate

public int executionCostEstimate()

Return a relative cost estimate for executing the expression.

Overrides:

executionCostEstimate in class Literal

isZero

public boolean isZero()

Return true if the value of this literal is known to be false.

Overrides:

isZero in class Literal

hasTrueFalseResult

public boolean hasTrueFalseResult()

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

Overrides:

hasTrueFalseResult in class Expression