package org.odmg;

/**
 * The ODMG Set collection interface.
 * A <code>DSet</code> object is an unordered collection that does not support
 * multiple elements with the same value. An implementation typically is very
 * efficient at determining whether the collection contains a particular value.
 * <p>
 * All of the operations defined by the JavaSoft <code>Set</code>
 * interface are supported by an ODMG implementation of <code>DSet</code>,
 * the exception <code>UnsupportedOperationException</code> is not thrown when a
 * call is made to any of the <code>Set</code> methods.
 * @author	David Jordan (as Java Editor of the Object Data Management Group)
 * @version ODMG 3.0
 */
// * @see java.lang.UnsupportedOperationException

public interface DSet extends DCollection, java.util.Set
{

    /**
     * Create a new <code>DSet</code> object that is the set union of this
     * <code>DSet</code> object and the set referenced by <code>otherSet</code>.
     * @param	otherSet	The other set to be used in the union operation.
     * @return	A newly created <code>DSet</code> instance that contains the union of the two sets.
     */
    public DSet union(DSet otherSet);

    /**
     * Create a new <code>DSet</code> object that is the set intersection of this
     * <code>DSet</code> object and the set referenced by <code>otherSet</code>.
     * @param	otherSet	The other set to be used in the intersection operation.
     * @return	A newly created <code>DSet</code> instance that contains the
     * intersection of the two sets.
     */
    public DSet intersection(DSet otherSet);

    /**
     * Create a new <code>DSet</code> object that contains the elements of this
     * collection minus the elements in <code>otherSet</code>.
     * @param	otherSet	A set containing elements that should not be in the result set.
     * @return	A newly created <code>DSet</code> instance that contains the elements
     * of this set minus those elements in <code>otherSet</code>.
     */
    public DSet difference(DSet otherSet);

    /**
     * Determine whether this set is a subset of the set referenced by <code>otherSet</code>.
     * @param	otherSet	Another set.
     * @return True if this set is a subset of the set referenced by <code>otherSet</code>,
     * otherwise false.
     */
    public boolean subsetOf(DSet otherSet);

    /**
     * Determine whether this set is a proper subset of the set referenced by
     * <code>otherSet</code>.
     * @param	otherSet	Another set.
     * @return True if this set is a proper subset of the set referenced by
     * <code>otherSet</code>, otherwise false.
     */
    public boolean properSubsetOf(DSet otherSet);

    /**
     * Determine whether this set is a superset of the set referenced by <code>otherSet</code>.
     * @param	otherSet	Another set.
     * @return True if this set is a superset of the set referenced by <code>otherSet</code>,
     * otherwise false.
     */
    public boolean supersetOf(DSet otherSet);

    /**
     * Determine whether this set is a proper superset of the set referenced by
     * <code>otherSet</code>.
     * @param	otherSet	Another set.
     * @return True if this set is a proper superset of the set referenced by
     * <code>otherSet</code>, otherwise false.
     */
    public boolean properSupersetOf(DSet otherSet);
}