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* Licensed to the Apache Software Foundation (ASF) under one
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* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jena.rdf.model;
import java.util.Iterator;
import org.apache.jena.reasoner.* ;
/**
* An extension to the normal Model interface that supports access to any
* underlying inference capability.
* <p>In Jena the primary use of inference is
* to generate additional entailments from a set of RDF data. These entailments
* just appear as additional RDF data in the inferred model and are accessed
* through the normal API. For example, if an inference engine can determine
* the class of a resource "foo" is "fooClass" then all Model API calls such
* as listStatements and getProperty should act as if the triple:
* <pre>
* foo rdf:type fooClass .
* </pre>
* were in the data. </p>
*
* <p>A few reasoner services cannot be made directly available in this way
* and the InfGraph extension gives access to these - specifically access to
* validation/consistency checking, derivation traces and find-with-posits.</p>
*
* <p>Note that this interface, and especially the interface onto ValidityReports
* and Derivations are not yet stable.</p>
*/
public interface InfModel extends Model {
/**
* Return the raw RDF model being processed (i.e. the argument
* to the Reasonder.bind call that created this InfModel).
*/
public Model getRawModel();
/**
* Return the Reasoner which is being used to answer queries to this graph.
*/
public Reasoner getReasoner();
/**
* Cause the inference model to reconsult the underlying data to take
* into account changes. Normally changes are made through the InfModel's add and
* remove calls are will be handled appropriately. However, in some cases changes
* are made "behind the InfModels's back" and this forces a full reconsult of
* the changed data.
*/
public void rebind();
/**
* Perform any initial processing and caching. This call is optional. Most
* engines either have negligable set up work or will perform an implicit
* "prepare" if necessary. The call is provided for those occasions where
* substantial preparation work is possible (e.g. running a forward chaining
* rule system) and where an application might wish greater control over when
* this prepration is done rather than just leaving to be done at first query time.
*/
public void prepare();
/**
* Reset any internal caches. Some systems, such as the tabled backchainer,
* retain information after each query. A reset will wipe this information preventing
* unbounded memory use at the expense of more expensive future queries. A reset
* does not cause the raw data to be reconsulted and so is less expensive than a rebind.
*/
public void reset();
/**
* Test the consistency of the underlying data. This normally tests
* the validity of the bound instance data against the bound
* schema data.
* <p>Logically inconsistent models will be indicated by a ValidityReport which
* reports isValid() as false. Additional non.error problems, such as uninstantiatable classes,
* may be reported as warnings.
* @return a ValidityReport structure
*/
public ValidityReport validate();
/** Find all the statements matching a pattern.
* <p>Return an iterator over all the statements in a model
* that match a pattern. The statements selected are those
* whose subject matches the <code>subject</code> argument,
* whose predicate matches the <code>predicate</code> argument
* and whose object matchesthe <code>object</code> argument.
* If an argument is <code>null</code> it matches anything.</p>
* <p>
* The s/p/o terms may refer to resources which are temporarily defined in the "posit" model.
* This allows one, for example, to query what resources are of type CE where CE is a
* class expression rather than a named class - put CE in the posit arg.</p>
*
* @return an iterator over the subjects
* @param subject The subject sought
* @param predicate The predicate sought
* @param object The value sought
*/
public StmtIterator listStatements( Resource subject, Property predicate, RDFNode object, Model posit );
/**
* Switch on/off drivation logging. If this is switched on then every time an inference
* is a made that fact is recorded and the resulting record can be access through a later
* getDerivation call. This may consume a lot of space!
*/
public void setDerivationLogging(boolean logOn);
/**
* Return the derivation of the given statement (which should be the result of
* some previous list operation).
* Not all reasoneers will support derivations.
* @return an iterator over Derivation records or null if there is no derivation information
* available for this triple.
* @see org.apache.jena.reasoner.Derivation Derviation
*/
public Iterator<Derivation> getDerivation(Statement statement);
/**
* Returns a derivations model. The rule reasoners typically create a
* graph containing those triples added to the base graph due to rule firings.
* In some applications it can useful to be able to access those deductions
* directly, without seeing the raw data which triggered them. In particular,
* this allows the forward rules to be used as if they were rewrite transformation
* rules.
* @return the deductions model, if relevant for this class of inference
* engine or null if not.
*/
public Model getDeductionsModel();
}