com.espertech.esper.epl.expression.visitor

Class ExprNodeVariableVisitor

java.lang.Object

com.espertech.esper.epl.expression.visitor.ExprNodeVariableVisitor

All Implemented Interfaces:

ExprNodeVisitor

public class ExprNodeVariableVisitor
extends Object
implements ExprNodeVisitor

Visitor for expression node trees that determines if the expressions within contain a variable.

Constructor Summary

Constructors

Constructor and Description
ExprNodeVariableVisitor(VariableService variableService)

Method Summary

Modifier and Type	Method and Description
Set<String>	getVariableNames() Returns the set of variable names encoountered.
boolean	isHasVariables() Returns true if the visitor finds a variable value.
boolean	isVisit(ExprNode exprNode) Allows visitor to indicate whether to visit a given node.
void	visit(ExprNode exprNode) Visit the given expression node.

Methods inherited from class java.lang.Object

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

Constructor Detail

ExprNodeVariableVisitor

public ExprNodeVariableVisitor(VariableService variableService)

Method Detail

isVisit

public boolean isVisit(ExprNode exprNode)

Description copied from interface: ExprNodeVisitor

Allows visitor to indicate whether to visit a given node. Implicitly if a visitor doesn't visit a node it would also not visit any descendent child nodes of that node.

Specified by:

isVisit in interface ExprNodeVisitor

Parameters:

exprNode - is the node in questions

Returns:

true if the visitor wants to visit the child node (next call is visit), or false to skip child

isHasVariables

public boolean isHasVariables()

Returns true if the visitor finds a variable value.

Returns:

true for variable present in expression

visit

public void visit(ExprNode exprNode)

Description copied from interface: ExprNodeVisitor

Visit the given expression node.

Specified by:

visit in interface ExprNodeVisitor

Parameters:

exprNode - is the expression node to visit

getVariableNames

public Set<String> getVariableNames()

Returns the set of variable names encoountered.

Returns:

variable names