| /******************************************************************************* |
| * Copyright (c) 2001, 2007 Oracle Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * Oracle Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jst.jsf.common.sets; |
| |
| import java.util.Set; |
| |
| /** |
| * A java.util.Set with the basic mathematic set axioms of |
| * extensionality (equality), union, intersection, |
| * relative complement (set subtraction) and empty (already |
| * supported by Set). |
| * |
| * <p><b>Provisional API - subject to change</b></p> |
| * |
| * @author cbateman |
| * |
| */ |
| public interface AxiomaticSet extends Set |
| { |
| /** |
| * Implementations should aim to provide O(mn) time cost |
| * where n is the number of elements in this set and |
| * m is the cost to check membership of an element in this |
| * set in toSet. When a set is itself a member of a set, |
| * the implementation must call isEquivalent on those subsets |
| * recursively. |
| * |
| * @param toSet |
| * |
| * @return true iff this set is equivalent toSet. Note |
| * that extensionality holds that two sets are equivalent |
| * if and only if they contain exactly the same elements. |
| * |
| * |
| */ |
| boolean isEquivalent(AxiomaticSet toSet); |
| |
| /** |
| * @param set |
| * @return the axiomatic union of this set with set |
| */ |
| AxiomaticSet union(AxiomaticSet set); |
| |
| |
| /** |
| * @param set |
| * @return the axiomatic intersection of this set with set |
| */ |
| AxiomaticSet intersect(AxiomaticSet set); |
| |
| /** |
| * @param set |
| * @return convenience method that must be equivalent to |
| * (this.intersect(set).isEmpty()) |
| */ |
| boolean isDisjoint(AxiomaticSet set); |
| |
| /** |
| * The set constructed by the removing the intersection |
| * of this with set from this. The set will contain all |
| * elements in this that are not in set. |
| * |
| * Eqivalence: this - set |
| * |
| * @param set |
| * @return the relative complement or theoretic difference of |
| * set from this |
| */ |
| AxiomaticSet subtract(AxiomaticSet set); |
| |
| /** |
| * @return the first element in the set. There is no guarantee which element |
| * will be chosen, but the call should always return the same element of the set |
| * for multiple invocations on the same set. Generally this is a convience method |
| * for when the set only contains one element. |
| * |
| * @throws java.util.NoSuchElementException if the set is empty. |
| */ |
| Object getFirstElement(); |
| } |