com.hp.hpl.jena.reasoner.rulesys

Class LPBackwardRuleReasoner

java.lang.Object

com.hp.hpl.jena.reasoner.rulesys.LPBackwardRuleReasoner

All Implemented Interfaces:

Reasoner

public class LPBackwardRuleReasoner
extends Object
implements Reasoner

Reasoner implementation which augments or transforms an RDF graph according to a set of rules. The rules are processed using a tabled LP backchaining interpreter which is implemented by the relvant InfGraph class.

Constructor Summary

Constructors

Constructor and Description
LPBackwardRuleReasoner(List<Rule> rules) Constructor.
LPBackwardRuleReasoner(List<Rule> rules, ReasonerFactory factory) Constructor

Method Summary

Methods

Modifier and Type	Method and Description
void	addDescription(Model configSpec, Resource base) Add a configuration description for this reasoner into a partial configuration specification model.
InfGraph	bind(Graph data) Attach the reasoner to a set of RDF data to process.
Reasoner	bindSchema(Graph tbox) Precompute the implications of a schema graph.
Reasoner	bindSchema(Model tbox) Precompute the implications of a schema Model.
Capabilities	getGraphCapabilities() Return the Jena Graph Capabilties that the inference graphs generated by this reasoner are expected to conform to.
Model	getReasonerCapabilities() Return a description of the capabilities of this reasoner encoded in RDF.
List<Rule>	getRules() Return the this of Rules used by this reasoner
void	setDerivationLogging(boolean logOn) Switch on/off drivation logging.
void	setParameter(Property parameter, Object value) Set a configuration paramter for the reasoner.
void	setTraceOn(boolean state) Set the state of the trace flag.
boolean	supportsProperty(Property property) Determine whether the given property is recognized and treated specially by this reasoner.
void	tablePredicate(Node predicate) Register an RDF predicate as one whose presence in a goal should force the goal to be tabled.

Methods inherited from class java.lang.Object

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

Constructor Detail

LPBackwardRuleReasoner

public LPBackwardRuleReasoner(List<Rule> rules)

Constructor. This is the raw version that does not reference a ReasonerFactory and so has no capabilities description.

Parameters:

rules - a list of Rule instances which defines the ruleset to process

LPBackwardRuleReasoner

public LPBackwardRuleReasoner(List<Rule> rules,
                      ReasonerFactory factory)

Constructor

Parameters:

rules - a list of Rule instances which defines the ruleset to process

factory - the parent reasoner factory which is consulted to answer capability questions

Method Detail

getReasonerCapabilities

public Model getReasonerCapabilities()

Return a description of the capabilities of this reasoner encoded in RDF. These capabilities may be static or may depend on configuration information supplied at construction time. May be null if there are no useful capabilities registered.

Specified by:

getReasonerCapabilities in interface Reasoner

addDescription

public void addDescription(Model configSpec,
                  Resource base)

Add a configuration description for this reasoner into a partial configuration specification model.

Specified by:

addDescription in interface Reasoner

Parameters:

configSpec - a Model into which the configuration information should be placed

base - the Resource to which the configuration parameters should be added.

tablePredicate

public void tablePredicate(Node predicate)

Register an RDF predicate as one whose presence in a goal should force the goal to be tabled.

supportsProperty

public boolean supportsProperty(Property property)

Determine whether the given property is recognized and treated specially by this reasoner. This is a convenience packaging of a special case of getCapabilities.

Specified by:

supportsProperty in interface Reasoner

Parameters:

property - the property which we want to ask the reasoner about, given as a Node since this is part of the SPI rather than API

Returns:

true if the given property is handled specially by the reasoner.

bindSchema

public Reasoner bindSchema(Graph tbox)
                    throws ReasonerException

Precompute the implications of a schema graph. The statements in the graph will be combined with the data when the final InfGraph is created.

Specified by:

bindSchema in interface Reasoner

Parameters:

tbox - the ontology axioms or rule set encoded in RDF

Returns:

a reasoner instace which can be used to process a data graph

Throws:

ReasonerException - if the reasoner cannot be bound to a rule set in this way, for example if the underlying engine can only accept a single rule set in this way and one rule set has already been bound in of if the ruleset is illformed.

bindSchema

public Reasoner bindSchema(Model tbox)
                    throws ReasonerException

Precompute the implications of a schema Model. The statements in the graph will be combined with the data when the final InfGraph is created.

Specified by:

bindSchema in interface Reasoner

Parameters:

tbox - the ontology axioms or rule set encoded in RDF

Returns:

a reasoner instace which can be used to process a data graph

Throws:

ReasonerException - if the reasoner cannot be bound to a rule set in this way, for example if the underlying engine can only accept a single rule set in this way and one rule set has already been bound in of if the ruleset is illformed.

bind

public InfGraph bind(Graph data)
              throws ReasonerException

Attach the reasoner to a set of RDF data to process. The reasoner may already have been bound to specific rules or ontology axioms (encoded in RDF) through earlier bindRuleset calls.

Specified by:

bind in interface Reasoner

Parameters:

data - the RDF data to be processed, some reasoners may restrict the range of RDF which is legal here (e.g. syntactic restrictions in OWL).

Returns:

an inference graph through which the data+reasoner can be queried.

Throws:

ReasonerException - if the data is ill-formed according to the constraints imposed by this reasoner.

getRules

public List<Rule> getRules()

Return the this of Rules used by this reasoner

Returns:

a List of Rule objects

setDerivationLogging

public void setDerivationLogging(boolean logOn)

Switch on/off drivation logging. If set to true then the InfGraph created from the bind operation will start life with recording of derivations switched on. This is currently only of relevance to rule-based reasoners.

Default - false.

Specified by:

setDerivationLogging in interface Reasoner

setTraceOn

public void setTraceOn(boolean state)

Set the state of the trace flag. If set to true then rule firings are logged out to the Logger at "INFO" level.

setParameter

public void setParameter(Property parameter,
                Object value)

Set a configuration paramter for the reasoner. In the case of the this reasoner there are no configuration parameters and this method is simply here to meet the interfaces specification

Specified by:

setParameter in interface Reasoner

Parameters:

parameter - the property identifying the parameter to be changed

value - the new value for the parameter, typically this is a wrapped java object like Boolean or Integer.

getGraphCapabilities

public Capabilities getGraphCapabilities()

Return the Jena Graph Capabilties that the inference graphs generated by this reasoner are expected to conform to.

Specified by:

getGraphCapabilities in interface Reasoner