org.semanticweb.elk.reasoner.saturation.rules.contextinit.RootContextInitializationRule Maven / Gradle / Ivy

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package org.semanticweb.elk.reasoner.saturation.rules.contextinit;

/*
 * #%L
 * ELK Reasoner
 * $Id:$
 * $HeadURL:$
 * %%
 * Copyright (C) 2011 - 2015 Department of Computer Science, University of Oxford
 * %%
 * Licensed 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,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */

import org.semanticweb.elk.reasoner.indexing.classes.DummyIndexedContextRootVisitor;
import org.semanticweb.elk.reasoner.indexing.model.IndexedClassExpression;
import org.semanticweb.elk.reasoner.indexing.model.IndexedContextRoot;
import org.semanticweb.elk.reasoner.indexing.model.IndexedRangeFiller;
import org.semanticweb.elk.reasoner.indexing.model.ModifiableOntologyIndex;
import org.semanticweb.elk.reasoner.saturation.conclusions.model.ContextInitialization;
import org.semanticweb.elk.reasoner.saturation.conclusions.model.SubClassInclusion;
import org.semanticweb.elk.reasoner.saturation.context.Context;
import org.semanticweb.elk.reasoner.saturation.context.ContextPremises;
import org.semanticweb.elk.reasoner.saturation.inferences.SubClassInclusionRange;
import org.semanticweb.elk.reasoner.saturation.inferences.SubClassInclusionTautology;
import org.semanticweb.elk.reasoner.saturation.rules.ClassInferenceProducer;
import org.semanticweb.elk.util.collections.chains.Chain;
import org.semanticweb.elk.util.collections.chains.Matcher;
import org.semanticweb.elk.util.collections.chains.ReferenceFactory;
import org.semanticweb.elk.util.collections.chains.SimpleTypeBasedMatcher;

/**
 * A {@link ChainableContextInitRule} that produces a {@link SubClassInclusion} for the
 * root of the given {@link Context}.
 * 
 * @see Context#getRoot()
 * 
 * @author "Yevgeny Kazakov"
 */
public class RootContextInitializationRule extends
		AbstractChainableContextInitRule {

	public static final String NAME = "Root Introduction";

	private RootContextInitializationRule(ChainableContextInitRule tail) {
		super(tail);
	}

	private RootContextInitializationRule() {
		super(null);
	}

	/**
	 * Add a {@link RootContextInitializationRule} to the given
	 * {@link ModifiableOntologyIndex}
	 * 
	 * @param index
	 *            a {@link ModifiableOntologyIndex} in which the rule should be
	 *            added
	 * @return {@code true} if the operation was successful and {@code false}
	 *         otherwise; if {@code false} is returned, the index remains
	 *         unchanged
	 */
	public static boolean addRuleFor(ModifiableOntologyIndex index) {
		return index.addContextInitRule(new RootContextInitializationRule());
	}

	/**
	 * Removes a {@link RootContextInitializationRule} to the given
	 * {@link ModifiableOntologyIndex}
	 * 
	 * @param index
	 *            a {@link ModifiableOntologyIndex} in which the rule should be
	 *            removed
	 * @return {@code true} if the operation was successful and {@code false}
	 *         otherwise; if {@code false} is returned, the index remains
	 *         unchanged
	 */
	public static boolean removeRuleFor(ModifiableOntologyIndex index) {
		return index.removeContextInitRule(new RootContextInitializationRule());
	}

	@Override
	public String toString() {
		return NAME;
	}

	@Override
	public void apply(ContextInitialization premise,
			final ContextPremises premises, final ClassInferenceProducer producer) {
		IndexedContextRoot root = premises.getRoot();
		producer.produce(new SubClassInclusionTautology(premises.getRoot()));
		root.accept(new DummyIndexedContextRootVisitor() {

			@Override
			public Void visit(IndexedRangeFiller element) {
				for (IndexedClassExpression range : element.getProperty()
						.getSaturated().getRanges()) {
					producer.produce(
							new SubClassInclusionRange(element, range));
				}
				return null;
			}
		});

	}

	@Override
	public boolean isTracingRule() {
		return true;
	}

	@Override
	public boolean addTo(Chain ruleChain) {
		RootContextInitializationRule rule = ruleChain.find(MATCHER_);
		if (rule == null) {
			ruleChain.getCreate(MATCHER_, FACTORY_);
		}
		return true;
	}

	@Override
	public boolean removeFrom(Chain ruleChain) {
		return ruleChain.remove(MATCHER_) != null;
	}

	@Override
	public void accept(LinkedContextInitRuleVisitor visitor,
			ContextInitialization premise, ContextPremises premises,
			ClassInferenceProducer producer) {
		visitor.visit(this, premise, premises, producer);
	}

	private static final Matcher MATCHER_ = new SimpleTypeBasedMatcher(
			RootContextInitializationRule.class);

	private static final ReferenceFactory FACTORY_ = new ReferenceFactory() {
		@Override
		public RootContextInitializationRule create(
				ChainableContextInitRule tail) {
			return new RootContextInitializationRule(tail);
		}
	};

}