1/*
2 * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23import java.util.HashSet;
24import java.util.AbstractSet;
25import java.util.Collection;
26import java.util.Iterator;
27import java.util.Set;
28import java.util.function.Supplier;
29
30/**
31 * @library
32 *
33 * A simple mutable set implementation that provides only default
34 * implementations of all methods. ie. none of the Set interface default methods
35 * have overridden implementations.
36 *
37 * @param <E> type of set members
38 */
39public class ExtendsAbstractSet<E> extends AbstractSet<E> {
40
41    protected final Set<E> set;
42
43    public ExtendsAbstractSet() {
44        this(HashSet<E>::new);
45    }
46
47    public ExtendsAbstractSet(Collection<E> source) {
48        this();
49        addAll(source);
50    }
51
52    protected ExtendsAbstractSet(Supplier<Set<E>> backer) {
53        this.set = backer.get();
54    }
55
56    public boolean add(E element) {
57        return set.add(element);
58    }
59
60    public boolean remove(Object element) {
61        return set.remove(element);
62    }
63
64    public Iterator<E> iterator() {
65        return new Iterator<E>() {
66            Iterator<E> source = set.iterator();
67
68            public boolean hasNext() {
69                return source.hasNext();
70            }
71
72            public E next() {
73                return source.next();
74            }
75
76            public void remove() {
77                source.remove();
78            }
79        };
80    }
81
82    public int size() {
83        return set.size();
84    }
85}
86