keyedcursoruos.java

国外的数据结构与算法分析用书

/* KeyedCursorUos.java
 * ---------------------------------------------
 * Copyright (c) 2001 University of Saskatchewan
 * All Rights Reserved
 * --------------------------------------------- */
 
package dslib.base;

import dslib.exception.NoCurrentItemUosException;


/**	A Cursor with a key.  Item refers to the current item, itemKey 
	is the key of the current item, and itemExists determines if 
	the cursor is presently referring to an item in the structure. */
public interface KeyedCursorUos extends CursorUos
{
	/**	The key of the current item. <br>
		PRECONDITION: <br>
		<ul>
			itemExists()
		</ul> */
	public Comparable itemKey() throws NoCurrentItemUosException;

	/**	The current key-item pair. <br>
		PRECONDITION: <br>
		<ul>
			itemExists()
		</ul> */
	public PairUos keyItemPair() throws NoCurrentItemUosException;
}