com.espertech.esper.epl.expression.visitor

Class ExprNodeStreamSelectVisitor

java.lang.Object

com.espertech.esper.epl.expression.visitor.ExprNodeStreamSelectVisitor

All Implemented Interfaces:

ExprNodeVisitor

public class ExprNodeStreamSelectVisitor
extends Object
implements ExprNodeVisitor

Visitor that collects event property identifier information under expression nodes. The visitor can be configued to not visit aggregation nodes thus ignoring properties under aggregation nodes such as sum, avg, min/max etc.

Constructor Summary

Constructors

Constructor and Description
ExprNodeStreamSelectVisitor(boolean visitAggregateNodes) Ctor.

Method Summary

Modifier and Type	Method and Description
boolean	hasStreamSelect()
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

ExprNodeStreamSelectVisitor

public ExprNodeStreamSelectVisitor(boolean visitAggregateNodes)

Ctor.

Parameters:

visitAggregateNodes - true to indicate that the visitor should visit aggregate nodes, or false if the visitor ignores aggregate nodes

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

hasStreamSelect

public boolean hasStreamSelect()

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