package stack;

/**
 * An interface for the ADT stack.
 * 
 * @author Frank M. Carrano
 * @author Timothy M. Henry
 * @author maellis1
 * @version May 2020 
 */
public interface StackInterface<T> {
    /**
     * Adds a new entry to the top of this stack.
     * 
     * @param newEntry
     *            An object to be added to the stack.
     */
    public void push(T newEntry);

    /**
     * Removes and returns this stack's top entry.
     * 
     * @return The object at the top of the stack.
     * @throws stack.EmptyStackException
     *             if the stack is empty before the operation.
     */
    public T pop();

    /**
     * Retrieves this stack's top entry.
     * 
     * @return The object at the top of the stack.
     * @throws stack.EmptyStackException
     *             if the stack is empty.
     */
    public T peek();

    /**
     * Detects whether this stack is empty.
     * 
     * @return True if the stack is empty.
     */
    public boolean isEmpty();

    /** Removes all entries from this stack. */
    public void clear();
} // end StackInterface