org.drools.base.evaluators
Class IsAEvaluatorDefinition.IsAEvaluator

java.lang.Object
  org.drools.base.BaseEvaluator
      org.drools.base.evaluators.IsAEvaluatorDefinition.IsAEvaluator

All Implemented Interfaces:

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

Enclosing class:

IsAEvaluatorDefinition

public static class IsAEvaluatorDefinition.IsAEvaluator
extends BaseEvaluator

See Also:

Serialized Form

Constructor Summary

IsAEvaluatorDefinition.IsAEvaluator(ValueType type, boolean isNegated)

Method Summary

boolean	evaluate(InternalWorkingMemory workingMemory, InternalReadAccessor extractor, InternalFactHandle handle, FieldValue value) Evaluates the expression using the provided parameters.
boolean	evaluate(InternalWorkingMemory workingMemory, InternalReadAccessor leftExtractor, InternalFactHandle left, InternalReadAccessor rightExtractor, InternalFactHandle right) 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.
protected TraitableBean	lookForWrapper(Object objectValue, InternalWorkingMemory workingMemory)
void	setParameterText(String parameterText)
String	toString()

Methods inherited from class org.drools.base.BaseEvaluator

equals, getCoercedValueType, getInterval, getOperator, getValueType, hashCode, isTemporal, readExternal, writeExternal

Methods inherited from class java.lang.Object

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

Constructor Detail

IsAEvaluatorDefinition.IsAEvaluator

public IsAEvaluatorDefinition.IsAEvaluator(ValueType type,
                                           boolean isNegated)

Method Detail

setParameterText

public void setParameterText(String parameterText)

evaluate

public boolean evaluate(InternalWorkingMemory workingMemory,
                        InternalReadAccessor extractor,
                        InternalFactHandle handle,
                        FieldValue value)

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

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

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

Returns:

Returns true if evaluation is successful. false otherwise.

lookForWrapper

protected TraitableBean lookForWrapper(Object objectValue,
                                       InternalWorkingMemory workingMemory)

evaluate

public boolean evaluate(InternalWorkingMemory workingMemory,
                        InternalReadAccessor leftExtractor,
                        InternalFactHandle left,
                        InternalReadAccessor rightExtractor,
                        InternalFactHandle right)

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

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

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

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

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.

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.

toString

public String toString()

Overrides:

toString in class BaseEvaluator