com.metamatrix.query.sql.visitor
Class EvaluatableVisitor

java.lang.Object
  com.metamatrix.query.sql.LanguageVisitor
      com.metamatrix.query.sql.visitor.EvaluatableVisitor

public class EvaluatableVisitor
extends LanguageVisitor

This visitor class will traverse a language object tree, and determine if the current expression can be evaluated

The public visit() methods should NOT be called directly.

There are three possible scenarios: duringPlanning | fullyEvaluatable --------------------------------- false | false = will become processing time constant false | true = processing time evaluation possible true | true = planning time evaluation possible (should always be deterministic)

Field Summary

protected boolean

evaluationPossible

Constructor Summary

EvaluatableVisitor(boolean duringPlanning, boolean fullyEvaluatable)

Method Summary

boolean	isEvaluationPossible()
void	visit(AggregateSymbol obj)
void	visit(DependentSetCriteria obj)
void	visit(ElementSymbol obj)
void	visit(ExistsCriteria obj)
void	visit(ExpressionSymbol obj)
void	visit(Function obj)
void	visit(Reference obj)
void	visit(ScalarSubquery obj)
void	visit(StoredProcedure proc)
void	visit(SubqueryCompareCriteria obj)
void	visit(SubquerySetCriteria obj)

Methods inherited from class com.metamatrix.query.sql.LanguageVisitor

setAbort, shouldAbort, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

evaluationPossible

protected boolean evaluationPossible

Constructor Detail

EvaluatableVisitor

public EvaluatableVisitor(boolean duringPlanning,
                          boolean fullyEvaluatable)

Method Detail

visit

public void visit(Function obj)

Overrides:

visit in class LanguageVisitor

visit

public void visit(ElementSymbol obj)

Overrides:

visit in class LanguageVisitor

visit

public void visit(ExpressionSymbol obj)

Overrides:

visit in class LanguageVisitor

visit

public void visit(AggregateSymbol obj)

Overrides:

visit in class LanguageVisitor

visit

public void visit(Reference obj)

Overrides:

visit in class LanguageVisitor

visit

public void visit(StoredProcedure proc)

Overrides:

visit in class LanguageVisitor

visit

public void visit(ScalarSubquery obj)

Overrides:

visit in class LanguageVisitor

visit

public void visit(DependentSetCriteria obj)

Overrides:

visit in class LanguageVisitor

visit

public void visit(ExistsCriteria obj)

Overrides:

visit in class LanguageVisitor

visit

public void visit(SubquerySetCriteria obj)

Overrides:

visit in class LanguageVisitor

visit

public void visit(SubqueryCompareCriteria obj)

Overrides:

visit in class LanguageVisitor

isEvaluationPossible

public boolean isEvaluationPossible()