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

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

All Implemented Interfaces:

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

public class ExprEqualsNodeImpl
extends ExprNodeBase
implements ExprEqualsNode

Represents an equals (=) comparator in a filter expressiun tree.

See Also:

Serialized Form

Nested Class Summary

static class	ExprEqualsNodeImpl.ExprEqualsEvaluatorCoercing
static class	ExprEqualsNodeImpl.ExprEqualsEvaluatorEquals
static class	ExprEqualsNodeImpl.ExprEqualsEvaluatorIs

Constructor Summary

ExprEqualsNodeImpl(boolean isNotEquals, boolean isIs)
Ctor.

Method Summary

boolean	equalsNode(ExprNode node) Return true if a expression node semantically equals the current node, or false if not.
java.util.Map<java.lang.String,java.lang.Object>	getEventType()
ExprEvaluator	getExprEvaluator()
ExprPrecedenceEnum	getPrecedence() Returns precedence.
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	isIs() Returns true if this is a "IS" or "IS NOT" node, false if this is a EQUALS or NOT EQUALS node.
boolean	isNotEquals() Returns true if this is a NOT EQUALS node, false if this is a EQUALS node.
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

Methods inherited from interface com.espertech.esper.epl.expression.core.ExprNode

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

Constructor Detail

ExprEqualsNodeImpl

public ExprEqualsNodeImpl(boolean isNotEquals,
                          boolean isIs)

Ctor.

Parameters:

isNotEquals - - true if this is a (!=) not equals rather then equals, false if its a '=' equals

isIs - - true when "is" or "is not" (instead of = or <>)

Method Detail

getExprEvaluator

public ExprEvaluator getExprEvaluator()

Specified by:

getExprEvaluator in interface ExprNode

isNotEquals

public boolean isNotEquals()

Description copied from interface: ExprEqualsNode

Returns true if this is a NOT EQUALS node, false if this is a EQUALS node.

Specified by:

isNotEquals in interface ExprEqualsNode

Returns:

true for !=, false for =

isIs

public boolean isIs()

Description copied from interface: ExprEqualsNode

Returns true if this is a "IS" or "IS NOT" node, false if this is a EQUALS or NOT EQUALS node.

Specified by:

isIs in interface ExprEqualsNode

Returns:

true for !=, false for =

validate

public ExprNode validate(ExprValidationContext validationContext)
                  throws ExprValidationException

Specified by:

validate in interface ExprValidator

Throws:

ExprValidationException

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

getEventType

public java.util.Map<java.lang.String,java.lang.Object> getEventType()

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

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