1 package org.djutils.immutablecollections;
2
3 import java.util.Collection;
4 import java.util.HashSet;
5 import java.util.Set;
6
7 /**
8 * An immutable wrapper for a HashSet.
9 * <p>
10 * Copyright (c) 2016-2019 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See
11 * for project information <a href="https://djutils.org" target="_blank"> https://djutils.org</a>. The DJUTILS project is
12 * distributed under a three-clause BSD-style license, which can be found at
13 * <a href="https://djutils.org/docs/license.html" target="_blank"> https://djutils.org/docs/license.html</a>.
14 * </p>
15 * @author <a href="https://www.tudelft.nl/averbraeck">Alexander Verbraeck</a>
16 * @author <a href="https://www.tudelft.nl/staff/p.knoppers/">Peter Knoppers</a>
17 * @author <a href="https://www.transport.citg.tudelft.nl">Wouter Schakel</a>
18 * @param <E> the type of content of this Set
19 */
20 public class ImmutableHashSet<E> extends ImmutableAbstractSet<E>
21 {
22 /** */
23 private static final long serialVersionUID = 20160507L;
24
25 /**
26 * @param collection Collection<? extends E>; the collection to use for the immutable set.
27 */
28 public ImmutableHashSet(final Collection<? extends E> collection)
29 {
30 super(new HashSet<E>(collection), Immutable.COPY);
31 }
32
33 /**
34 * @param set Set<E>; the set to use for the immutable set.
35 * @param copyOrWrap COPY stores a safe, internal copy of the collection; WRAP stores a pointer to the original collection
36 */
37 public ImmutableHashSet(final Set<E> set, final Immutable copyOrWrap)
38 {
39 super(copyOrWrap == Immutable.COPY ? new HashSet<E>(set) : set, copyOrWrap);
40 }
41
42 /**
43 * @param collection ImmutableAbstractCollection<? extends E>; the collection to use for the immutable set.
44 */
45 public ImmutableHashSet(final ImmutableAbstractCollection<? extends E> collection)
46 {
47 super(new HashSet<E>(collection.getCollection()), Immutable.COPY);
48 }
49
50 /**
51 * @param set ImmutableAbstractSet<E>; the set to use for the immutable set.
52 * @param copyOrWrap COPY stores a safe, internal copy of the collection; WRAP stores a pointer to the original collection
53 */
54 public ImmutableHashSet(final ImmutableAbstractSet<E> set, final Immutable copyOrWrap)
55 {
56 super(copyOrWrap == Immutable.COPY ? new HashSet<E>(set.getCollection()) : set.getCollection(), copyOrWrap);
57 }
58
59 /** {@inheritDoc} */
60 @Override
61 protected Set<E> getCollection()
62 {
63 return super.getCollection();
64 }
65
66 /** {@inheritDoc} */
67 @Override
68 public final Set<E> toSet()
69 {
70 return new HashSet<E>(getCollection());
71 }
72
73 /** {@inheritDoc} */
74 @Override
75 @SuppressWarnings("checkstyle:designforextension")
76 public String toString()
77 {
78 Set<E> set = getCollection();
79 if (null == set)
80 {
81 return "ImmutableHashSet []";
82 }
83 return "ImmutableHashSet [" + set.toString() + "]";
84 }
85
86 }