scale.clef.stmt
Class NullStmt

java.lang.Object
  scale.common.Root
      scale.clef.Node
          scale.clef.stmt.Statement
              scale.clef.stmt.NullStmt

All Implemented Interfaces:

AnnotationInterface, DisplayNode

public class NullStmt
extends Statement

This class represents a placeholder statement such as a missing else clause.

$Id: NullStmt.java,v 1.21 2006-06-28 16:39:03 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

NullStmt()

Method Summary

void	visit(Predicate p) Process a node by calling its associated routine.

Methods inherited from class scale.clef.stmt.Statement

containsLoopStmt, dump, getDisplayColorHint, getDisplayLabel, getDisplayShapeHint, getPragma, getSourceLineNumber, hasReturnStmt, numTotalStmts, setPragma, setSourceLineNumber

Methods inherited from class scale.clef.Node

getChild, getCoreType, getDecl, getType, numChildren, setAnnotationLevel, setReportLevel, toString, toString, toStringChildren, toStringSpecial

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

NullStmt

public NullStmt()

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 Statement

See Also:

Predicate