com.espertech.esper.epl.expression.prev

Class ExprPreviousNode

java.lang.Object

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

com.espertech.esper.epl.expression.prev.ExprPreviousNode

All Implemented Interfaces:

ExprEnumerationEval, ExprEnumerationForge, ExprEvaluator, ExprForge, ExprNode, ExprNodeRenderable, ExprValidator, MetaDefItem, java.io.Serializable

public class ExprPreviousNode
extends ExprNodeBase
implements ExprEvaluator, ExprEnumerationForge, ExprEnumerationEval, ExprForge

Represents the 'prev' previous event function in an expression node tree.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ExprPreviousNode(ExprPreviousNodePreviousType previousType)

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.
java.lang.Object	evaluate(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext) Evaluate event tuple and return result.
CodegenExpression	evaluateCodegen(java.lang.Class requiredType, CodegenMethodScope codegenMethodScope, ExprForgeCodegenSymbol exprSymbol, CodegenClassScope codegenClassScope)
EventBean	evaluateGetEventBean(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext context)
CodegenExpression	evaluateGetEventBeanCodegen(CodegenMethodScope codegenMethodScope, ExprForgeCodegenSymbol exprSymbol, CodegenClassScope codegenClassScope)
java.util.Collection<EventBean>	evaluateGetROCollectionEvents(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext context)
CodegenExpression	evaluateGetROCollectionEventsCodegen(CodegenMethodScope codegenMethodScope, ExprForgeCodegenSymbol exprSymbol, CodegenClassScope codegenClassScope)
java.util.Collection	evaluateGetROCollectionScalar(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext context)
CodegenExpression	evaluateGetROCollectionScalarCodegen(CodegenMethodScope codegenMethodScope, ExprForgeCodegenSymbol exprSymbol, CodegenClassScope codegenClassScope)
ExprForgeComplexityEnum	getComplexity()
java.lang.Class	getComponentTypeCollection()
java.lang.Integer	getConstantIndexNumber()
java.lang.Class	getEvaluationType()
EventType	getEventTypeCollection(EventAdapterService eventAdapterService, int statementId)
EventType	getEventTypeSingle(EventAdapterService eventAdapterService, int statementId)
ExprEvaluator	getExprEvaluator()
ExprEnumerationEval	getExprEvaluatorEnumeration()
ExprForge	getForge()
ExprNode	getForgeRenderable()
ExprPrecedenceEnum	getPrecedence() Returns precedence.
ExprPreviousNodePreviousType	getPreviousType()
java.lang.Class	getResultType()
int	getStreamNumber()
int	hashCode()
boolean	isConstantIndex()
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	setEvaluator(ExprPreviousEvalStrategy evaluator)
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, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ExprPreviousNode

public ExprPreviousNode(ExprPreviousNodePreviousType previousType)

Method Detail

getExprEvaluator

public ExprEvaluator getExprEvaluator()

Specified by:

getExprEvaluator in interface ExprForge

setEvaluator

public void setEvaluator(ExprPreviousEvalStrategy evaluator)

getStreamNumber

public int getStreamNumber()

getConstantIndexNumber

public java.lang.Integer getConstantIndexNumber()

isConstantIndex

public boolean isConstantIndex()

getResultType

public java.lang.Class getResultType()

getForge

public ExprForge getForge()

Specified by:

getForge in interface ExprNode

getExprEvaluatorEnumeration

public ExprEnumerationEval getExprEvaluatorEnumeration()

Specified by:

getExprEvaluatorEnumeration in interface ExprEnumerationForge

getEvaluationType

public java.lang.Class getEvaluationType()

Specified by:

getEvaluationType in interface ExprForge

validate

public ExprNode validate(ExprValidationContext validationContext)
                  throws ExprValidationException

Specified by:

validate in interface ExprValidator

Throws:

ExprValidationException

getPreviousType

public ExprPreviousNodePreviousType getPreviousType()

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

evaluateGetROCollectionEvents

public java.util.Collection<EventBean> evaluateGetROCollectionEvents(EventBean[] eventsPerStream,
                                                                     boolean isNewData,
                                                                     ExprEvaluatorContext context)

Specified by:

evaluateGetROCollectionEvents in interface ExprEnumerationEval

evaluateGetROCollectionEventsCodegen

public CodegenExpression evaluateGetROCollectionEventsCodegen(CodegenMethodScope codegenMethodScope,
                                                              ExprForgeCodegenSymbol exprSymbol,
                                                              CodegenClassScope codegenClassScope)

Specified by:

evaluateGetROCollectionEventsCodegen in interface ExprEnumerationForge

evaluateGetEventBean

public EventBean evaluateGetEventBean(EventBean[] eventsPerStream,
                                      boolean isNewData,
                                      ExprEvaluatorContext context)

Specified by:

evaluateGetEventBean in interface ExprEnumerationEval

evaluateGetEventBeanCodegen

public CodegenExpression evaluateGetEventBeanCodegen(CodegenMethodScope codegenMethodScope,
                                                     ExprForgeCodegenSymbol exprSymbol,
                                                     CodegenClassScope codegenClassScope)

Specified by:

evaluateGetEventBeanCodegen in interface ExprEnumerationForge

evaluateGetROCollectionScalar

public java.util.Collection evaluateGetROCollectionScalar(EventBean[] eventsPerStream,
                                                          boolean isNewData,
                                                          ExprEvaluatorContext context)

Specified by:

evaluateGetROCollectionScalar in interface ExprEnumerationEval

evaluateGetROCollectionScalarCodegen

public CodegenExpression evaluateGetROCollectionScalarCodegen(CodegenMethodScope codegenMethodScope,
                                                              ExprForgeCodegenSymbol exprSymbol,
                                                              CodegenClassScope codegenClassScope)

Specified by:

evaluateGetROCollectionScalarCodegen in interface ExprEnumerationForge

getEventTypeCollection

public EventType getEventTypeCollection(EventAdapterService eventAdapterService,
                                        int statementId)
                                 throws ExprValidationException

Specified by:

getEventTypeCollection in interface ExprEnumerationForge

Throws:

ExprValidationException

getEventTypeSingle

public EventType getEventTypeSingle(EventAdapterService eventAdapterService,
                                    int statementId)
                             throws ExprValidationException

Specified by:

getEventTypeSingle in interface ExprEnumerationForge

Throws:

ExprValidationException

getComponentTypeCollection

public java.lang.Class getComponentTypeCollection()
                                           throws ExprValidationException

Specified by:

getComponentTypeCollection in interface ExprEnumerationForge

Throws:

ExprValidationException

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.

evaluateCodegen

public CodegenExpression evaluateCodegen(java.lang.Class requiredType,
                                         CodegenMethodScope codegenMethodScope,
                                         ExprForgeCodegenSymbol exprSymbol,
                                         CodegenClassScope codegenClassScope)

Specified by:

evaluateCodegen in interface ExprForge

getComplexity

public ExprForgeComplexityEnum getComplexity()

Specified by:

getComplexity in interface ExprForge

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

getForgeRenderable

public ExprNode getForgeRenderable()

Specified by:

getForgeRenderable in interface ExprEnumerationForge

Specified by:

getForgeRenderable in interface ExprForge

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

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