org.drools.base.evaluators
Class MetByEvaluatorDefinition.MetByEvaluator

java.lang.Object
  org.drools.base.BaseEvaluator
      org.drools.base.evaluators.MetByEvaluatorDefinition.MetByEvaluator

All Implemented Interfaces:

Externalizable, Serializable, org.drools.runtime.rule.Evaluator

Enclosing class:

MetByEvaluatorDefinition

public static class MetByEvaluatorDefinition.MetByEvaluator
extends BaseEvaluator

Implements the 'metby' evaluator itself

See Also:

Serialized Form

Constructor Summary

MetByEvaluatorDefinition.MetByEvaluator()

MetByEvaluatorDefinition.MetByEvaluator(ValueType type, boolean isNegated, Long[] parameters, String paramText)

Method Summary

boolean	equals(Object obj)
boolean	evaluate(InternalWorkingMemory workingMemory, InternalReadAccessor extractor, InternalFactHandle object1, FieldValue object2) Evaluates the expression using the provided parameters.
boolean	evaluate(InternalWorkingMemory workingMemory, InternalReadAccessor extractor1, InternalFactHandle handle1, InternalReadAccessor extractor2, InternalFactHandle handle2) Evaluates the expression using the provided parameters.
boolean	evaluateCachedLeft(InternalWorkingMemory workingMemory, VariableRestriction.VariableContextEntry context, InternalFactHandle right) Evaluates the expression using the provided parameters.
boolean	evaluateCachedRight(InternalWorkingMemory workingMemory, VariableRestriction.VariableContextEntry context, InternalFactHandle left) Evaluates the expression using the provided parameters.
Interval	getInterval() In case this is a temporal evaluator, returns the interval in which this evaluator may match the target fact
int	hashCode()
boolean	isTemporal() Returns true if this evaluator implements a temporal evaluation, i.e., a time sensitive evaluation whose properties of matching only events within an specific time interval can be used for determining event expirations automatically.
void	readExternal(ObjectInput in)
String	toString()
void	writeExternal(ObjectOutput out)

Methods inherited from class org.drools.base.BaseEvaluator

getCoercedValueType, getOperator, getValueType

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

MetByEvaluatorDefinition.MetByEvaluator

public MetByEvaluatorDefinition.MetByEvaluator()

MetByEvaluatorDefinition.MetByEvaluator

public MetByEvaluatorDefinition.MetByEvaluator(ValueType type,
                                               boolean isNegated,
                                               Long[] parameters,
                                               String paramText)

Method Detail

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

Specified by:

readExternal in interface Externalizable

Overrides:

readExternal in class BaseEvaluator

Throws:

IOException

ClassNotFoundException

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Specified by:

writeExternal in interface Externalizable

Overrides:

writeExternal in class BaseEvaluator

Throws:

IOException

isTemporal

public boolean isTemporal()

Description copied from interface: Evaluator

Returns true if this evaluator implements a temporal evaluation, i.e., a time sensitive evaluation whose properties of matching only events within an specific time interval can be used for determining event expirations automatically.

Specified by:

isTemporal in interface org.drools.runtime.rule.Evaluator

Overrides:

isTemporal in class BaseEvaluator

Returns:

true if the evaluator is a temporal evaluator.

getInterval

public Interval getInterval()

Description copied from interface: Evaluator

In case this is a temporal evaluator, returns the interval in which this evaluator may match the target fact

Overrides:

getInterval in class BaseEvaluator

Returns:

evaluate

public boolean evaluate(InternalWorkingMemory workingMemory,
                        InternalReadAccessor extractor,
                        InternalFactHandle object1,
                        FieldValue object2)

Description copied from interface: Evaluator

Evaluates the expression using the provided parameters. This method is used when evaluating alpha-constraints, i.e., a fact attribute against a constant value. For instance: Person( name == "Bob" ) So, it uses a constant value "Bob" that is sent into the method as the FieldValue (value), and compares it to the value of the name field, read by using the extractor on the fact instance (object1).

Parameters:

workingMemory - The current working memory

extractor - The extractor used to get the field value from the object

object1 - The source object to evaluate, i.e., the fact

object2 - The actual value to compare to, i.e., the constant value.

Returns:

Returns true if evaluation is successful. false otherwise.

evaluateCachedRight

public boolean evaluateCachedRight(InternalWorkingMemory workingMemory,
                                   VariableRestriction.VariableContextEntry context,
                                   InternalFactHandle left)

Description copied from interface: Evaluator

Evaluates the expression using the provided parameters. This method is used when evaluating right-activated beta-constraints, i.e., a fact attribute against a variable value, that is activated from the right. For instance: Person( name == $someName ) This method will be used when a new Person instance is evaluated. So it will cache the value of the "Person" instance and will iterate over the left memory comparing it to each "$someName" bound values.

Parameters:

workingMemory - The current working memory

context - The previously cached context, including the right value and the extractor for the left value.

left - The left object, from where to extract the bound variable. In the above example, that is the "$someName" variable value.

Returns:

Returns true if evaluation is successful. false otherwise.

evaluateCachedLeft

public boolean evaluateCachedLeft(InternalWorkingMemory workingMemory,
                                  VariableRestriction.VariableContextEntry context,
                                  InternalFactHandle right)

Description copied from interface: Evaluator

Evaluates the expression using the provided parameters. This method is used when evaluating left-activated beta-constraints, i.e., a fact attribute against a variable value, that is activated from the left. For instance: Person( name == $someName ) This method will be used when a new $someName variable is bound. So it will cache the value of $someName and will iterate over the right memory (Person instances) evaluating each occurrence.

Parameters:

workingMemory - The current working memory

context - The previously cached context, including the left value and the extractor for the right value.

right - The right object, from where to extract the value. In the above example, that is the "Person" instance from where to extract the "name" attribute.

Returns:

Returns true if evaluation is successful. false otherwise.

evaluate

public boolean evaluate(InternalWorkingMemory workingMemory,
                        InternalReadAccessor extractor1,
                        InternalFactHandle handle1,
                        InternalReadAccessor extractor2,
                        InternalFactHandle handle2)

Description copied from interface: Evaluator

Evaluates the expression using the provided parameters. This method is used for internal indexing and hashing, when drools needs to extract and evaluate both left and right values at once. For instance: Person( name == $someName ) This method will be used to extract and evaluate both the "name" attribute and the "$someName" variable at once.

Parameters:

workingMemory - The current working memory

extractor1 - The extractor to read the left value. In the above example, the "$someName" variable value.

handle1 - The source object from where the value of the variable is extracted.

extractor2 - The extractor to read the right value. In the above example, the "name" attribute value.

handle2 - The right object from where to extract the value. In the above example, that is the "Person" instance from where to extract the "name" attribute.

Returns:

Returns true if evaluation is successful. false otherwise.

toString

public String toString()

Overrides:

toString in class BaseEvaluator

hashCode

public int hashCode()

Overrides:

hashCode in class BaseEvaluator

equals

public boolean equals(Object obj)

Overrides:

equals in class BaseEvaluator