scale.clef.expr
Class IdValueOp

java.lang.Object
  scale.common.Root
      scale.clef.Node
          scale.clef.expr.Expression
              scale.clef.expr.IdReferenceOp
                  scale.clef.expr.IdValueOp

All Implemented Interfaces:

AnnotationInterface, DisplayNode

public class IdValueOp
extends IdReferenceOp

A class which represents the value of a Declaration.

$Id: IdValueOp.java,v 1.13 2007-06-04 00:30:13 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

IdValueOp(Declaration decl)
Create the representation of the value of the specified declaration.

Method Summary

Literal	getConstantValue() This method suite computes the value of a constant expression.
java.lang.String	getDisplayLabel() Return short description of current node.
boolean	isConstant() Returns true if the IdValueOp represents a constant value.
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.IdReferenceOp

containsDeclaration, equivalent, getDecl, getDeclList, setDecl

Methods inherited from class scale.clef.expr.Expression

canonical, getCoreType, getDisplayColorHint, getDisplayShapeHint, getPointedToCore, getType, hasTrueFalseResult, isSimpleOp, setType

Methods inherited from class scale.clef.Node

getChild, 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

IdValueOp

public IdValueOp(Declaration decl)

Create the representation of the value of the specified declaration.

Method Detail

getDisplayLabel

public java.lang.String getDisplayLabel()

Return short description of current node.

Specified by:

getDisplayLabel in interface DisplayNode

Overrides:

getDisplayLabel 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 IdReferenceOp

See Also:

Predicate

isConstant

public boolean isConstant()

Returns true if the IdValueOp represents a constant value.

getConstantValue

public Literal getConstantValue()

This method suite computes the value of a constant expression.

Okay, this is a bit messy. For IdValueOps, we have to ensure that the declared entity is a constant. The fact that this is a constant is stored with the the type.

These method instances currently handle all IdValueOps (i.e., the subclasses of this class). If SelectScopeOp and SelectGlobalScopeOp ever get completed, this may have to be moved down into IdReference.

Overrides:

getConstantValue in class IdReferenceOp

See Also:

IdValueOp