jtp.frame.fc
Class OptimizedRuleInstantiator

java.lang.Object
  |
  +--java.beans.beancontext.BeanContextChildSupport
        |
        +--jtp.util.PropertyImporter
              |
              +--jtp.frame.fc.RuleInstantiator
                    |
                    +--jtp.frame.fc.OptimizedRuleInstantiator

All Implemented Interfaces:

BeanContextChild, BeanContextServiceRevokedListener, BeanContextServicesListener, EventListener, Reasoner, Serializable

public class OptimizedRuleInstantiator

extends RuleInstantiator

Overrides RuleInstantiator.acceptable(Object) to reduce the likelihood of process(java.lang.Object) getting invoked, thus (hopefully) optimizing it.

See Also:

Serialized Form

Field Summary

protected Hashtable

alreadySeen Hashtable of all Literals that have been previously seen by this reasoner.

Fields inherited from class jtp.frame.fc.RuleInstantiator

tm

Fields inherited from class java.beans.beancontext.BeanContextChildSupport

beanContext, beanContextChildPeer, pcSupport, rejectedSetBCOnce, vcSupport

Constructor Summary

OptimizedRuleInstantiator()

Method Summary

boolean	acceptable(Object goal) Returns false if the goal Literal's relation's package is jtp.frame.fc or if the holdified Literal is in the alreadySeen Hashtable.
ReasoningStepIterator	process(Object o) This method attempts to find proof for the goal.

Methods inherited from class jtp.frame.fc.RuleInstantiator

addTrigger, getAskingReasoner, getUndoManager, removeTrigger, setAskingReasoner, setUndoManager

Methods inherited from class jtp.util.PropertyImporter

getImportedProperties, initializeBeanContextResources, setImportedProperties

Methods inherited from class java.beans.beancontext.BeanContextChildSupport

addPropertyChangeListener, addVetoableChangeListener, firePropertyChange, fireVetoableChange, getBeanContext, getBeanContextChildPeer, isDelegated, releaseBeanContextResources, removePropertyChangeListener, removeVetoableChangeListener, serviceAvailable, serviceRevoked, setBeanContext, validatePendingSetBeanContext

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

alreadySeen

protected Hashtable alreadySeen

Hashtable of all Literals that have been previously seen by this reasoner. The Literals should be DefaultLiterals that have been holdified by HoldsReasoner.holdify(jtp.fol.Literal).

Constructor Detail

OptimizedRuleInstantiator

public OptimizedRuleInstantiator()

Method Detail

acceptable

public boolean acceptable(Object goal)

Returns false if the goal Literal's relation's package is jtp.frame.fc or if the holdified Literal is in the alreadySeen Hashtable.

Specified by:

acceptable in interface Reasoner

Overrides:

acceptable in class RuleInstantiator

Returns:

true if the goal is suitable for this reasoner, false otherwise.

process

public ReasoningStepIterator process(Object o)

Description copied from interface: Reasoner

This method attempts to find proof for the goal. It returns an enumeration of reasoning steps that correspond to alternative proofs for the goal. Consequently, the items of the enumeration can actually belong to different models of the goal sentence, and have incompatible variable assignments.

Example. A reasoner that performs unification of the goal with facts in a knowledge base can return the following enumeration for the goal (parent joe ?x):

1. A reasoning step proving (parent joe fred) with variable assignment ?x=fred,
2. A reasoning step proving (parent joe mary) with variable assignment ?x=mary.

Specified by:

process in interface Reasoner

Overrides:

process in class RuleInstantiator

Parameters:

o - the goal: either a query or an assertion

Returns:

the iterator of reasoning steps - proofs for the query, or consequences of the assertion.