/*
 * Copyright (c) 2012, Synflow
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *   * Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation
 *     and/or other materials provided with the distribution.
 *   * Neither the name of the IETR/INSA of Rennes nor the names of its
 *     contributors may be used to endorse or promote products derived from this
 *     software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
package net.sf.orcc.graph.visit;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import net.sf.orcc.graph.Vertex;

/**
 * This class defines an ordering.
 * 
 * @author Matthieu Wipliez
 * 
 */
public abstract class Ordering implements Iterable<Vertex> {

	protected final List<Vertex> vertices;

	protected final Set<Vertex> visited;

	/**
	 * Creates a new topological sorter.
	 */
	public Ordering() {
		vertices = new ArrayList<Vertex>();
		visited = new HashSet<Vertex>();
	}

	/**
	 * Creates a new topological sorter.
	 * 
	 * @param n
	 *            the expected number of vertices
	 */
	protected Ordering(int n) {
		vertices = new ArrayList<Vertex>(n);
		visited = new HashSet<Vertex>(n);
	}

	/**
	 * Returns the list of vertices in the specified order.
	 * 
	 * @return the list of vertices in the specified order
	 */
	public List<Vertex> getVertices() {
		return vertices;
	}

	@Override
	public Iterator<Vertex> iterator() {
		return vertices.iterator();
	}

}