/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file 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,
 * 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.
 */
package org.apache.commons.math.genetics;

/**
 * A collection of chromosomes that facilitates generational evolution.
 * 
 * @since 2.0
 * @version $Revision:$ $Date:$
 */
public interface Population extends Iterable<Chromosome> {
	/**
	 * Access the current population size.
	 * 
	 * @return the current population size.
	 */
	int getPopulationSize();

	/**
	 * Access the maximum population size.
	 * 
	 * @return the maximum population size.
	 */
	int getPopulationLimit();

	/**
	 * Start the population for the next generation.
	 * 
	 * @return the beginnings of the next generation.
	 */
	Population nextGeneration();

	/**
	 * Add the given chromosome to the population.
	 * 
	 * @param chromosome
	 *            the chromosome to add.
	 */
	void addChromosome(Chromosome chromosome);

	/**
	 * Access the fittest chromosome in this population.
	 * 
	 * @return the fittest chromosome.
	 */
	Chromosome getFittestChromosome();
}
