package containers;

public interface IOrderedContainer {

    /**
     * If there is an object associated with key
     * then this object is returned else null is returned.
     */
    public Object find(IOrdered key);

    /**
     * Returns the (key,value) with the next smaller key
     * from that specified, regardless of whether the
     * specified key is itself in the container.  If
     * there isn't a (key,value) with a smaller key,
     * returns null.
     */
    public KeyValuePair findPrev(IOrdered key);

    /**
     * Returns the (key,value) with the next larger key
     * from that specified, regardless of whether the
     * specified key is itself in the container.  If
     * there isn't a (key,value) with a larger key,
     * returns null.
     */
    public KeyValuePair findNext(IOrdered key);
    
    /**
     * Afterwards, find(key) returns null, and if there is
     * an object associated with key then this object is
     * returned else null is returned.
     */
    public Object remove(IOrdered key);

    /**
     * (key, value) is stored in this container with no
     * duplication and such that find(key) returns value.
     */
    public void insert(IOrdered key, Object value);
}