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

Class ExprOrderedExpr

java.lang.Object

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

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

All Implemented Interfaces:

ExprEvaluator, ExprForge, ExprNode, ExprNodeRenderable, ExprValidator

public class ExprOrderedExpr
extends ExprNodeBase
implements ExprForge, ExprEvaluator

A placeholder expression for view/pattern object parameters that allow sorting expression values ascending or descending.

Field Summary

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

EPTYPE, EPTYPEARRAY

Constructor Summary

Constructors

Constructor	Description
ExprOrderedExpr(boolean descending)	Ctor.

Method Summary

Modifier and Type	Method	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)	Evaluate event tuple and return result.
CodegenExpression	evaluateCodegen(EPTypeClass requiredType, CodegenMethodScope codegenMethodScope, ExprForgeCodegenSymbol exprSymbol, CodegenClassScope codegenClassScope)
EPType	getEvaluationType()
ExprEvaluator	getExprEvaluator()
ExprForge	getForge()
ExprForgeConstantType	getForgeConstantType()
ExprNodeRenderable	getForgeRenderable()
ExprPrecedenceEnum	getPrecedence()	Returns precedence.
boolean	isDescending()	Returns true for descending sort.
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

Constructor Details

ExprOrderedExpr

public ExprOrderedExpr(boolean descending)

Ctor.

Parameters:

descending - is true for descending sorts

Method Details

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

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

getForgeRenderable

public ExprNodeRenderable getForgeRenderable()

Specified by:

getForgeRenderable in interface ExprForge

getForgeConstantType

public ExprForgeConstantType getForgeConstantType()

Specified by:

getForgeConstantType in interface ExprForge

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

validate

public ExprNode validate(ExprValidationContext validationContext)
                  throws ExprValidationException

Specified by:

validate in interface ExprValidator

Throws:

ExprValidationException

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.

evaluateCodegen

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

Specified by:

evaluateCodegen in interface ExprForge

isDescending

public boolean isDescending()

Returns true for descending sort.

Returns:

indicator for ascending or descending sort