Source of Bag.java

Structures and functions

  2: import java.util.Collection;

  4: /**
  5:  * A data type representing an unordered collection of items, possibly 
  6:  * including duplicates.
  7:  *
  8:  * @author Mark Young (A00000000)
  9:  */
 10: public interface Bag<T> extends Collection<T> {
 11:     
 12:     /**
 13:      * Remove an item from this Bag. The item to remove is at the discretion of
 14:      * the implementation.
 15:      *
 16:      * @return an arbitrary item removed from this Bag
 17:      * @throws java.util.NoSuchElementException if the Bag was empty
 18:      */
 19:     public T remove();

 21:     /**
 22:      * Count how many times the given item appears in this Bag. An item gets
 23:      * counted if {@code Objects.equals} reports it equal to the given item.
 24:      *
 25:      * @param anItem the item to count
 26:      * @return how many copies of that item appear in this Bag
 27:      */
 28:     public int getFrequency(T anItem);

 30: }