package studentDB;
/**
 *	Maintains a list of students.  Students may be entered
 *	into the list and retrieved from the list.
 */
public interface StudentList {

    /**
     *	Returns the number of elements in the list.
     *  @return Number of elements in the list.
     */
    public int numElements ();

    /**
     *	Determines whether given element is in the list.
     */
    public boolean inList (Object element);

    /**
     *	Removes the list element at posision n. Indexing is
     *  zero-based, so it must hold that 0<=n<numElements.
     */
    public void remove (int n);

    /**
     *	Determines whether the list is empty.  This is equivalent
     *	to testing whether numElements == 0.
     */
    public boolean isEmpty();

    /**
     *	Returns the list in printable form.
     */
    public String toString ();

    /**
     *	Returns the student at position n.  Indexing is
     *  zero-based, so it must hold that 0<=n<numElements.
     */
    public Student get (int n);

    /**
     *	Returns the first student in the list.  The list may not
     *  be empty.
     *	@return The first student in the list.
     */
    public Student first();
    
    /**
     *  Returns the list of students following the first student.
     *	The list may not be empty.
     *	@return The list of students following the first element.
     */
    public StudentList rest();

    /**
     *	Adds the given student to the end of the list.
     *	If the student is already in the list, has no effect.
     *	@param newStudent The element being added
     */
    public void add (Student newStudent);
}