com.ibm.able.examples.rules
Class PluggableEngine

java.lang.Object
  com.ibm.able.rules.AbleInferenceEngine
      com.ibm.able.examples.rules.PluggableEngine

All Implemented Interfaces:

java.io.Serializable

public class PluggableEngine

extends AbleInferenceEngine

This class extends the AbleInferenceEngine class so that it can be used as a customized pluggable inference engine. It can be used in any AbleRuleSet by specifying " using com.ibm.able.examples.rules.PluggableEngine" on the ruleblock definition.

See Also:

Serialized Form

Field Summary

Fields inherited from class com.ibm.able.rules.AbleInferenceEngine

myDebugLevel, myRuleBlock, myRuleSet, myRulesFiredCount, myTracer, myWorkingMemory

Constructor Summary

PluggableEngine(AbleRuleSet theRuleSet, AbleLogger theTracer, AbleRuleBlock theRuleBlock)
Create a new inference engine.

Method Summary

java.lang.Object	getControlParameter(java.lang.String theControlParameter) Get the specified control parameter on this inference engine.
void	infer(AbleRuleBlock theRuleBlock) Fire the rules in the ruleset in sequential order.
boolean	isRuleBlockValid(AbleRuleBlock theRuleBlock) Make sure the current ruleblock is "executable" by this inference engine.
void	reevaluateClausesWithChangedVariable(AbleClauseReferences theClauseReferences) Re-evaluate, if necessary, the specified clauses that contain a reference to a variable whose current value has just changed.
void	setControlParameter(java.lang.String theControlParameter, java.lang.Object theValue) Set the specified control parameter on this inference engine.

Methods inherited from class com.ibm.able.rules.AbleInferenceEngine

allocateWorkingMemory, askUser, conditionalRulesValid, evalAntecedentClause, evalAntecedentExpression, evalAssertionClause, evalAssertionRule, evalConditionalRule, evalConsequentClause, evalDoUntilRule, evalDoWhileRule, evalForLoopRule, evalIfThenElseRule, evalPatternMatchRule, evalSwitchRule, evaluateDoActions, evalWhileDoRule, fireEngineBreakpoint, firePropertyChange, getRuleSet, getRulesFiredCount, getWorkingMemory, init, processAssertions, processConsequent, processConsequent, processConsequentClauses, processRuleBlock, reset, resetRuleSet, setControlParameters, setDebugLevel, setInferenceContext, setInferenceContext, setInferenceContext, setRuleSet, setWorkingMemory, startDebugConsole, stopDebugConsole, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

PluggableEngine

public PluggableEngine(AbleRuleSet theRuleSet,
                       AbleLogger theTracer,
                       AbleRuleBlock theRuleBlock)

Create a new inference engine.

Parameters:

theRuleSet - A ruleset whose context is used for inferencing by this inference engine.

theTracer - A tracer object to which this inference engine can log information. This may be null, in which case no information is logged.

theRuleBlock - A ruleblock whose rules are to be used for inferencing by this inference engine.

Method Detail

isRuleBlockValid

public boolean isRuleBlockValid(AbleRuleBlock theRuleBlock)

Make sure the current ruleblock is "executable" by this inference engine.

Here is the place where the custom engine examines the rules the user coded in this ruleblock to see if they are acceptable for processing by this engine. In this example, we simply say whatever they pass is ok for us since we are going to ignore all but assertions anyway.

Specified by:

isRuleBlockValid in class AbleInferenceEngine

Returns:

true, if the ruleset is OK; false, if the ruleset is not executable.

infer

public void infer(AbleRuleBlock theRuleBlock)
           throws AbleDataException

Fire the rules in the ruleset in sequential order.

The order of processing is as follows:

1. All rules in the ruleblock are fired sequentially.

Specified by:

infer in class AbleInferenceEngine

Parameters:

theRuleBlock - The ruleblock used by this inference engine.

Throws:

AbleDataException - When any error occurs.

reevaluateClausesWithChangedVariable

public void reevaluateClausesWithChangedVariable(AbleClauseReferences theClauseReferences)
                                          throws AbleDataException

Re-evaluate, if necessary, the specified clauses that contain a reference to a variable whose current value has just changed. This engine processes only antecedent clauses.

Parameters:

theClauseReferences - A collection of clauses that reference some variable whose current value has just changed.

Throws:

AbleDataException

setControlParameter

public void setControlParameter(java.lang.String theControlParameter,
                                java.lang.Object theValue)
                         throws AbleDataException

Set the specified control parameter on this inference engine. Both the parameter name and value must be validated in this method.

Specified by:

setControlParameter in class AbleInferenceEngine

Throws:

AbleDataException

getControlParameter

public java.lang.Object getControlParameter(java.lang.String theControlParameter)
                                     throws AbleDataException

Get the specified control parameter on this inference engine.

Specified by:

getControlParameter in class AbleInferenceEngine

Throws:

AbleDataException