// *******************************************************************************
// Interface SortedListInterface
// *******************************************************************************

public interface SortedListInterface 
{

   public int size( );
   // Description: Determines the length of a list (number of elements stored in the list).
   // Precondition: None.
   // Postcondition: Returns the number of elements that are currently stored in the list.
   // Throws: None.

   public void removeAll( );
   // Description: Deletes all the elements from the list.
   // Precondition: None.
   // Postcondition: The list is empty.
   // Throws: None.

   public void insert( Object thisElement ) throws ListException;
   // Description: Adds an element to the list.
   // Precondition: "thisElement" is not null (?)
   // Postcondition: If insertion is successful, "thisElement" has been inserted at the proper
   //                location based on the sorting order(s) of the list.
   // Throws: ListException if "thisElement" cannot be placed in the list for whathever reason.

   public Object retrieve( Object criteria ) throws ElementNotFoundException;
   // Description: Retrieves a list element that matches "criteria".
   // Precondition: Since "criteria" is the criteria to utilise when searching the list, 
   //               "criteria" must not be null.
   // Postcondition: If "criteria" is found, the corresponding object in the list is returned. 
   //                The list is unchanged.
   // Throws: ElementNotFoundException if "criteria" is not found in the list.  

   public Object remove( Object criteria ) throws ElementNotFoundException;
   // Description: Removes the element that matches "criteria" from the list.
   // Precondition: Since "criteria" is the criteria to utilise when searching the list, 
   //               "criteria" must not be null.
   // Postcondition: If "criteria" is found, the corresponding object is removed from the list.
   // Throws: ElementNotFoundException if "criteria" is not found in the list. 
      
} // end SortedListInterface