org.coode.oppl.bindingtree.LeafBrusher Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of oppl2-oppl2 Show documentation
There is a newer version: 5.0.0
/**
 * Copyright (C) 2008, University of Manchester
 *
 * Modifications to the initial code base are copyright of their
 * respective authors, or their employers as appropriate.  Authorship
 * of the modifications may be determined from the ChangeLog placed at
 * the end of this file.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.

 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.

 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
package org.coode.oppl.bindingtree;

import static org.coode.oppl.utils.ArgCheck.checkNotNull;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import org.coode.oppl.Variable;
import org.semanticweb.owlapi.model.OWLObject;
import org.semanticweb.owlapi.model.OWLOntology;

/** @author Luigi Iannone */
public class LeafBrusher implements BindingVisitor {
    private final Set leaves = new HashSet();
    private final Map, Set> bindings = new HashMap, Set>();

    /** @param bindings
     *            bindings */
    public LeafBrusher(Map, Set> bindings) {
        this.bindings.putAll(checkNotNull(bindings, "bindings"));
    }

    @Override
    public void visit(BindingNode bindingNode) {
        if (!bindingNode.isEmpty()) {
            Set nodes = new HashSet();
            nodes.add(bindingNode);
            boolean allLeaves = bindingNode.isLeaf();
            while (!allLeaves) {
                for (BindingNode generatedChild : new HashSet(nodes)) {
                    if (!generatedChild.isLeaf()) {
                        nodes.remove(generatedChild);
                        Set generatedChildren = generateChildren(generatedChild);
                        nodes.addAll(generatedChildren);
                    }
                    allLeaves = allLeaves(nodes);
                }
            }
            leaves.addAll(nodes);
        }
    }

    /** @param nodes
     *            nodes
     * @return true if all nodes are leaves */
    private boolean allLeaves(Set nodes) {
        Iterator it = nodes.iterator();
        BindingNode generatedChild;
        boolean allLeaves = true;
        while (allLeaves && it.hasNext()) {
            generatedChild = it.next();
            allLeaves = generatedChild.isLeaf();
        }
        return allLeaves;
    }

    /** @return the leaves */
    public Set getLeaves() {
        return new HashSet(leaves);
    }

    private Set generateChildren(BindingNode node) {
        Set toReturn = new HashSet();
        if (node.isLeaf()) {
            toReturn.add(node);
            return toReturn;
        }
        Set> unassignedVariables = node.getUnassignedVariables();
        for (Variable variable : unassignedVariables) {
            Set values = bindings.get(variable);
            if (values != null) {
                for (OWLObject owlObject : values) {
                    if (!(owlObject instanceof OWLOntology)) {
                        Assignment extraAssignment = new Assignment(variable, owlObject);
                        BindingNode newNode = new BindingNode(node.getAssignments(),
                                unassignedVariables);
                        newNode.addAssignment(extraAssignment);
                        toReturn.add(newNode);
                    }
                }
            }
        }
        return toReturn;
    }

    /** @return the bindings */
    public Map, Set> getBindings() {
        return new HashMap, Set>(bindings);
    }
}