com.espertech.esper.epl.expression
Class ExprSubstitutionNode

java.lang.Object
  extended by com.espertech.esper.epl.expression.ExprNodeBase
      extended by com.espertech.esper.epl.expression.ExprSubstitutionNode
All Implemented Interfaces:
ExprNode, ExprValidator, MetaDefItem, java.io.Serializable

public class ExprSubstitutionNode
extends ExprNodeBase

Represents a substitution value to be substituted in an expression tree, not valid for any purpose of use as an expression, however can take a place in an expression tree.

See Also:
Serialized Form

Constructor Summary
ExprSubstitutionNode(int index)
          Ctor.
 
Method Summary
 boolean equalsNode(ExprNode node)
          Return true if a expression node semantically equals the current node, or false if not.
 java.lang.Object evaluate(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext)
           
 ExprEvaluator getExprEvaluator()
           
 int getIndex()
          Returns the substitution parameter index.
 java.lang.Class getType()
           
 boolean isConstantResult()
          Returns true if the expression node's evaluation value doesn't depend on any events data, as must be determined at validation time, which is bottom-up and therefore reliably allows each node to determine constant value.
 void setIndex(int index)
           
 java.lang.String toExpressionString()
          Returns the expression node rendered as a string.
 void validate(ExprValidationContext validationContext)
           
 
Methods inherited from class com.espertech.esper.epl.expression.ExprNodeBase
accept, accept, acceptChildnodes, addChildNode, addChildNodes, addChildNodeToFront, getChildNodes, replaceUnlistedChildNode, setChildNode, setChildNodes
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

ExprSubstitutionNode

public ExprSubstitutionNode(int index)
Ctor.

Parameters:
index - is the index of the substitution parameter
Method Detail

validate

public void validate(ExprValidationContext validationContext)
              throws ExprValidationException
Throws:
ExprValidationException

getIndex

public int getIndex()
Returns the substitution parameter index.

Returns:
index

setIndex

public void setIndex(int index)

isConstantResult

public boolean isConstantResult()
Description copied from interface: ExprNode
Returns true if the expression node's evaluation value doesn't depend on any events data, as must be determined at validation time, which is bottom-up and therefore reliably allows each node to determine constant value.

Returns:
true for constant evaluation value, false for non-constant evaluation value

getType

public java.lang.Class getType()

evaluate

public java.lang.Object evaluate(EventBean[] eventsPerStream,
                                 boolean isNewData,
                                 ExprEvaluatorContext exprEvaluatorContext)

getExprEvaluator

public ExprEvaluator getExprEvaluator()

toExpressionString

public java.lang.String toExpressionString()
Description copied from interface: ExprNode
Returns the expression node rendered as a string.

Returns:
string rendering of expression

equalsNode

public boolean equalsNode(ExprNode node)
Description copied from interface: ExprNode
Return true if a expression node semantically equals the current node, or false if not.

Concrete implementations should compare the type and any additional information that impact the evaluation of a node.

Parameters:
node - to compare to
Returns:
true if semantically equal, or false if not equals

© 2006-2014 EsperTech Inc.
All rights reserved.
Visit us at espertech.com