org.evrete.api

Interface EvaluatorsContext

All Known Subinterfaces:

Knowledge, RuleSession<S>, RuntimeContext<C>, StatefulSession, StatelessSession

public interface EvaluatorsContext

A collection of every condition tha was ever used in the engine's runtime. It allows developers to register an Evaluator and use its EvaluatorHandle to later update the supplied condition.

Method Summary

Modifier and Type	Method and Description
default EvaluatorHandle	addEvaluator(Evaluator evaluator)
EvaluatorHandle	addEvaluator(Evaluator evaluator, double complexity) Registers new condition evaluator and returns its handle.
Evaluator	getEvaluator(EvaluatorHandle handle) Returns evaluator by its handle.
void	replaceEvaluator(EvaluatorHandle handle, Evaluator newEvaluator) Replaces existing condition with a new one.
void	replaceEvaluator(EvaluatorHandle handle, ValuesPredicate predicate) Replaces existing condition with a new one.

Method Detail

addEvaluator

EvaluatorHandle addEvaluator(Evaluator evaluator,
                             double complexity)

Registers new condition evaluator and returns its handle. If an existing Evaluator matches the argument (Evaluator.compare(Evaluator) returns Evaluator.RELATION_EQUALS), the existing evaluator handle will be returned instead and no changes will be made in the context.

Parameters:

evaluator - condition to add

complexity - condition's relative complexity

Returns:

new EvaluatorHandle or the one of an existing condition.

getEvaluator

Evaluator getEvaluator(EvaluatorHandle handle)

Returns evaluator by its handle.

Parameters:

handle - evaluator handle

Returns:

existing condition evaluator or null if such condition does not exist

addEvaluator

default EvaluatorHandle addEvaluator(Evaluator evaluator)

Parameters:

evaluator - condition to add

Returns:

new EvaluatorHandle or the one of an existing condition.

See Also:

addEvaluator(Evaluator, double)

replaceEvaluator

void replaceEvaluator(EvaluatorHandle handle,
                      Evaluator newEvaluator)

Replaces existing condition with a new one. New condition must have the same Evaluator.descriptor(), otherwise IllegalArgumentException will be thrown.

Parameters:

handle - handle of an existing condition

newEvaluator - new condition

Throws:

IllegalArgumentException - if no condition can be found by the given handle or if the existing condition's descriptor does not match the new one.

replaceEvaluator

void replaceEvaluator(EvaluatorHandle handle,
                      ValuesPredicate predicate)

Replaces existing condition with a new one.

Parameters:

handle - handle of an existing condition

predicate - new condition in a form if ValuesPredicate