com.espertech.esper.epl.expression.core

Class ExprSubstitutionNode

java.lang.Object

com.espertech.esper.epl.expression.core.ExprNodeBase

com.espertech.esper.epl.expression.core.ExprSubstitutionNode

All Implemented Interfaces:

ExprNode, ExprNodeRenderable, ExprValidator, MetaDefItem, 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

Constructors

Constructor and Description
ExprSubstitutionNode(Integer index) Ctor.
ExprSubstitutionNode(String name) Ctor.

Method Summary

Modifier and Type	Method and Description
boolean	equalsNode(ExprNode node, boolean ignoreStreamPrefix) Return true if a expression node semantically equals the current node, or false if not.
Object	evaluate(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext)
ExprEvaluator	getExprEvaluator()
ExprForge	getForge()
Integer	getIndex() Returns the substitution parameter index (or null if by-name).
String	getName() Returns the substitution parameter name (or null if by-index).
ExprPrecedenceEnum	getPrecedence() Returns precedence.
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	toPrecedenceFreeEPL(StringWriter writer)
ExprNode	validate(ExprValidationContext validationContext)

Methods inherited from class com.espertech.esper.epl.expression.core.ExprNodeBase

accept, accept, acceptChildnodes, addChildNode, addChildNodes, addChildNodeToFront, getChildNodes, replaceUnlistedChildNode, setChildNode, setChildNodes, toEPL

Methods inherited from class java.lang.Object

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

Constructor Detail

ExprSubstitutionNode

public ExprSubstitutionNode(Integer index)

Ctor.

Parameters:

index - is the index of the substitution parameter

ExprSubstitutionNode

public ExprSubstitutionNode(String name)

Ctor.

Parameters:

name - is the name of the substitution parameter

Method Detail

validate

public ExprNode validate(ExprValidationContext validationContext)
                  throws ExprValidationException

Throws:

ExprValidationException

getIndex

public Integer getIndex()

Returns the substitution parameter index (or null if by-name).

Returns:

index

getName

public String getName()

Returns the substitution parameter name (or null if by-index).

Returns:

name

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 Class getType()

evaluate

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

getExprEvaluator

public ExprEvaluator getExprEvaluator()

getForge

public ExprForge getForge()

toPrecedenceFreeEPL

public void toPrecedenceFreeEPL(StringWriter writer)

Specified by:

toPrecedenceFreeEPL in class ExprNodeBase

getPrecedence

public ExprPrecedenceEnum getPrecedence()

Description copied from interface: ExprNode

Returns precedence.

Returns:

precedence

equalsNode

public boolean equalsNode(ExprNode node,
                          boolean ignoreStreamPrefix)

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

ignoreStreamPrefix - when the equals-comparison can ignore prefix of event properties

Returns:

true if semantically equal, or false if not equals