package rebelsky.mug;

/**
 * The world for Multi-User Grinnell.  Although it violates
 * some standards of object-oriented design, we use the world
 * as a central repository for all our objects.
 *
 * @author CSC152 2004F
 */
public interface World
{
	/**
	 * Determine where in the world something is.
	 */
	public Place whereIs(Noun something);
	
	/**
	 * Determine all the people in the world.
	 */
	public Person[] people();
	
	/**
	 * Determine what time it is in the world.
	 */
	public Time time();
	
	/**
	 * Indicate that some time has passed.
	 */
	void elapse();
	
	/**
	 * Record that an interaction has happened.  Return a comment on the
	 * results of the action.
	 *
	 * @exception
	 *   If the action is invalid or the object is invalid or ...
	 */
	public String interact(String actor, String action, String object)
		throws InvalidAction, InvalidTarget;
	public String interact(String actor, String action)
		throws InvalidAction;
} // interface World