Package com.espertech.esper.common.internal.epl.expression.core

Class ExprConstantNodeImpl

java.lang.Object

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

com.espertech.esper.common.internal.epl.expression.core.ExprConstantNodeImpl

All Implemented Interfaces:

ExprConstantNode, ExprEvaluator, ExprForge, ExprForgeInstrumentable, ExprNode, ExprNodeRenderable, ExprValidator

public class ExprConstantNodeImpl
extends ExprNodeBase
implements ExprConstantNode, ExprEvaluator, ExprForgeInstrumentable

Represents a constant in an expressiun tree.

Field Summary

Fields inherited from interface com.espertech.esper.common.internal.epl.expression.core.ExprEvaluator

EPTYPE, EPTYPEARRAY

Constructor Summary

Constructors

Constructor	Description
ExprConstantNodeImpl(EnumValue enumValue)
ExprConstantNodeImpl(Class type)	Ctor - for use when the constant should return a given type and the actual value is always null.
ExprConstantNodeImpl(Object value)
ExprConstantNodeImpl(Object value, EPType valueType)
ExprConstantNodeImpl(Object value, Class valueType)
ExprConstantNodeImpl(Object value, String stringConstantWhenProvided)

Method Summary

Modifier and Type	Method	Description
boolean	constantAvailable()
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)	Evaluate event tuple and return result.
CodegenExpression	evaluateCodegen(EPTypeClass requiredType, CodegenMethodScope codegenMethodScope, ExprForgeCodegenSymbol exprSymbol, CodegenClassScope codegenClassScope)
CodegenExpression	evaluateCodegenUninstrumented(EPTypeClass requiredType, CodegenMethodScope codegenMethodScope, ExprForgeCodegenSymbol exprSymbol, CodegenClassScope codegenClassScope)
EPType	getConstantType()
Object	getConstantValue()	Returns the constant's value.
EPType	getEvaluationType()
ExprEvaluator	getExprEvaluator()
ExprForge	getForge()
ExprForgeConstantType	getForgeConstantType()
ExprNodeRenderable	getForgeRenderable()
ExprPrecedenceEnum	getPrecedence()	Returns precedence.
String	getStringConstantWhenProvided()
boolean	isConstantResult()
void	setValue(Object value)	Sets the value of the constant.
void	toPrecedenceFreeEPL(StringWriter writer, ExprNodeRenderableFlags flags)
ExprNode	validate(ExprValidationContext validationContext)

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

accept, accept, acceptChildnodes, addChildNode, addChildNodes, addChildNodeToFront, checkValidated, checkValidatedException, 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.common.internal.epl.expression.core.ExprNode

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

Methods inherited from interface com.espertech.esper.common.internal.epl.expression.core.ExprNodeRenderable

toEPL

Constructor Details

ExprConstantNodeImpl

public ExprConstantNodeImpl(Object value,
 String stringConstantWhenProvided)

ExprConstantNodeImpl

public ExprConstantNodeImpl(Object value)

ExprConstantNodeImpl

public ExprConstantNodeImpl(EnumValue enumValue)

ExprConstantNodeImpl

public ExprConstantNodeImpl(Object value,
 EPType valueType)

ExprConstantNodeImpl

public ExprConstantNodeImpl(Object value,
 Class valueType)

ExprConstantNodeImpl

public ExprConstantNodeImpl(Class type)

Ctor - for use when the constant should return a given type and the actual value is always null.

Parameters:

type - the type of the constant null.

Method Details

getForgeConstantType

public ExprForgeConstantType getForgeConstantType()

Specified by:

getForgeConstantType in interface ExprForge

getExprEvaluator

public ExprEvaluator getExprEvaluator()

Specified by:

getExprEvaluator in interface ExprForge

getEvaluationType

public EPType getEvaluationType()

Specified by:

getEvaluationType in interface ExprForge

getForge

public ExprForge getForge()

Specified by:

getForge in interface ExprNode

getStringConstantWhenProvided

public String getStringConstantWhenProvided()

Specified by:

getStringConstantWhenProvided in interface ExprConstantNode

getForgeRenderable

public ExprNodeRenderable getForgeRenderable()

Specified by:

getForgeRenderable in interface ExprForge

constantAvailable

public boolean constantAvailable()

Specified by:

constantAvailable in interface ExprConstantNode

evaluateCodegen

public CodegenExpression evaluateCodegen(EPTypeClass requiredType,
 CodegenMethodScope codegenMethodScope,
 ExprForgeCodegenSymbol exprSymbol,
 CodegenClassScope codegenClassScope)

Specified by:

evaluateCodegen in interface ExprForge

evaluateCodegenUninstrumented

public CodegenExpression evaluateCodegenUninstrumented(EPTypeClass requiredType,
 CodegenMethodScope codegenMethodScope,
 ExprForgeCodegenSymbol exprSymbol,
 CodegenClassScope codegenClassScope)

Specified by:

evaluateCodegenUninstrumented in interface ExprForgeInstrumentable

validate

public ExprNode validate(ExprValidationContext validationContext)
                  throws ExprValidationException

Specified by:

validate in interface ExprValidator

Throws:

ExprValidationException

isConstantResult

public boolean isConstantResult()

getConstantValue

public Object getConstantValue()

Returns the constant's value.

Specified by:

getConstantValue in interface ExprConstantNode

Returns:

value of constant

setValue

public void setValue(Object value)

Sets the value of the constant.

Parameters:

value - to set

getConstantType

public EPType getConstantType()

Specified by:

getConstantType in interface ExprConstantNode

evaluate

public 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.

toPrecedenceFreeEPL

public void toPrecedenceFreeEPL(StringWriter writer,
 ExprNodeRenderableFlags flags)

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,
 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.

Specified by:

equalsNode in interface ExprNode

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