com.espertech.esper.epl.expression.ops
Class ExprLikeNode

java.lang.Object
  com.espertech.esper.epl.expression.core.ExprNodeBase
      com.espertech.esper.epl.expression.ops.ExprLikeNode

All Implemented Interfaces:

ExprEvaluator, ExprNode, ExprValidator, MetaDefItem, java.io.Serializable

public class ExprLikeNode
extends ExprNodeBase
implements ExprEvaluator

Represents the like-clause in an expression tree.

See Also:

Serialized Form

Constructor Summary

ExprLikeNode(boolean not)
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) Evaluate event tuple and return result.
ExprEvaluator	getExprEvaluator()
ExprPrecedenceEnum	getPrecedence() Returns precedence.
java.lang.Class	getType() Returns the type that the node's evaluate method returns an instance of.
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.
boolean	isNot() Returns true if this is a "not like", or false if just a like
void	toPrecedenceFreeEPL(java.io.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

ExprLikeNode

public ExprLikeNode(boolean not)

Ctor.

Parameters:

not - is true if this is a "not like", or false if just a like

Method Detail

getExprEvaluator

public ExprEvaluator getExprEvaluator()

Specified by:

getExprEvaluator in interface ExprNode

validate

public ExprNode validate(ExprValidationContext validationContext)
                  throws ExprValidationException

Specified by:

validate in interface ExprValidator

Throws:

ExprValidationException

getType

public java.lang.Class getType()

Description copied from interface: ExprEvaluator

Returns the type that the node's evaluate method returns an instance of.

Specified by:

getType in interface ExprEvaluator

Returns:

type returned when evaluated

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.

Specified by:

isConstantResult in interface ExprNode

Returns:

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

evaluate

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

Description copied from interface: ExprEvaluator

Evaluate event tuple and return result.

Specified by:

evaluate in interface ExprEvaluator

Parameters:

eventsPerStream - - event tuple

isNewData - - indicates whether we are dealing with new data (istream) or old data (rstream)

exprEvaluatorContext - context for expression evaluation

Returns:

evaluation result, a boolean value for OR/AND-type evalution nodes.

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.

Specified by:

equalsNode in interface ExprNode

Parameters:

node_ - to compare to

Returns:

true if semantically equal, or false if not equals

toPrecedenceFreeEPL

public void toPrecedenceFreeEPL(java.io.StringWriter writer)

Specified by:

toPrecedenceFreeEPL in class ExprNodeBase

getPrecedence

public ExprPrecedenceEnum getPrecedence()

Description copied from interface: ExprNode

Returns precedence.

Specified by:

getPrecedence in interface ExprNode

Returns:

precedence

isNot

public boolean isNot()

Returns true if this is a "not like", or false if just a like

Returns:

indicator whether negated or not