package de.ugoe.cs.quest.usageprofiles;

import java.util.List;

/**
 * <p>
 * This interface defines basic functions for classes that implement a memory
 * about the recent events of a sequences.
 * </p>
 * 
 * @author Steffen Herbold
 * @version 1.0
 * 
 * @param <T>
 *            Type of the sequence elements that are memorized.
 */
public interface IMemory<T> {

	/**
	 * Adds an element to the end of the memory.
	 * 
	 * @param element
	 *            Element to be added.
	 */
	public void add(T element);

	/**
	 * <p>
	 * Returns the last <code>num</code> memorized elements. If the history is
	 * shorter than <code>num</code>, the length of the returned
	 * {@link java.util.List} may be less than <code>num</code>.
	 * </p>
	 * 
	 * @param num
	 *            Number of states from the end of the memory to be returned.
	 * @return {@link java.util.List} of memorized elements.
	 */
	public List<T> getLast(int num);

}
