JavaParser/com/github/javaparser/utils/VisitorSet.java

1	/*
2	* Copyright (C) 2007-2010 Júlio Vilmar Gesser.
3	* Copyright (C) 2011, 2013-2020 The JavaParser Team.
4	*
5	* This file is part of JavaParser.
6	*
7	* JavaParser can be used either under the terms of
8	* a) the GNU Lesser General Public License as published by
9	* the Free Software Foundation, either version 3 of the License, or
10	* (at your option) any later version.
11	* b) the terms of the Apache License
12	*
13	* You should have received a copy of both licenses in LICENCE.LGPL and
14	* LICENCE.APACHE. Please refer to those files for details.
15	*
16	* JavaParser is distributed in the hope that it will be useful,
17	* but WITHOUT ANY WARRANTY; without even the implied warranty of
18	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19	* GNU Lesser General Public License for more details.
20	*/
21
22	package com.github.javaparser.utils;
23
24	import java.util.Collection;
25	import java.util.HashSet;
26	import java.util.Iterator;
27	import java.util.Set;
28	import java.util.stream.Collectors;
29
30	import com.github.javaparser.ast.Node;
31	import com.github.javaparser.ast.visitor.GenericVisitor;
32	import com.github.javaparser.ast.visitor.Visitable;
33	import com.github.javaparser.ast.visitor.VoidVisitor;
34
35	/**
36	* A set that overrides the equals and hashcode calculation of the added nodes
37	* by using another equals and hashcode visitor for those methods.
38	*/
39	public class VisitorSet<N extends Node> implements Set<N> {
40
41	private final Set<EqualsHashcodeOverridingFacade> innerSet = new HashSet<>();
42	private final GenericVisitor<Integer, Void> hashcodeVisitor;
43	private final GenericVisitor<Boolean, Visitable> equalsVisitor;
44
45	/**
46	* Pass the visitors to use for equals and hashcode.
47	*/
48	public VisitorSet(GenericVisitor<Integer, Void> hashcodeVisitor, GenericVisitor<Boolean, Visitable> equalsVisitor) {
49	this.hashcodeVisitor = hashcodeVisitor;
50	this.equalsVisitor = equalsVisitor;
51	}
52
53	@Override
54	public boolean add(N elem) {
55	return innerSet.add(new EqualsHashcodeOverridingFacade(elem));
56	}
57
58	@Override
59	public boolean addAll(Collection<? extends N> col) {
60	boolean modified = false;
61	for (N elem : col)
62	if (add(elem))
63	modified = true;
64	return modified;
65	}
66
67	@Override
68	public void clear() {
69	innerSet.clear();
70	}
71
72	@Override
73	public boolean contains(Object elem) {
74	return innerSet.contains(new EqualsHashcodeOverridingFacade((N) elem));
75	}
76
77	@Override
78	public boolean containsAll(Collection<?> col) {
79	for (Object elem : col)
80	if (!contains(elem))
81	return false;
82	return true;
83	}
84
85	@Override
86	public boolean isEmpty() {
87	return innerSet.isEmpty();
88	}
89
90	@Override
91	public Iterator<N> iterator() {
92	return new Iterator<N>() {
93	final Iterator<EqualsHashcodeOverridingFacade> itr = innerSet.iterator();
94
95	@Override
96	public boolean hasNext() {
97	return itr.hasNext();
98	}
99
100	@Override
101	public N next() {
102	return itr.next().overridden;
103	}
104
105	@Override
106	public void remove() {
107	itr.remove();
108	}
109	};
110	}
111
112	@Override
113	public boolean remove(Object elem) {
114	return innerSet.remove(new EqualsHashcodeOverridingFacade((N) elem));
115	}
116
117	@Override
118	public boolean removeAll(Collection<?> col) {
119	boolean modified = false;
120	for (Object elem : col)
121	if (remove(elem))
122	modified = true;
123	return modified;
124	}
125
126	@Override
127	public boolean retainAll(Collection<?> col) {
128	int oldSize = size();
129	clear();
130	addAll((Collection<? extends N>) col);
131	return size() != oldSize;
132	}
133
134	@Override
135	public int size() {
136	return innerSet.size();
137	}
138
139	@Override
140	public Object[] toArray() {
141	return innerSet.stream().map(facade -> facade.overridden).collect(Collectors.toList()).toArray();
142	}
143
144	@Override
145	public <T> T[] toArray(T[] arr) {
146	return innerSet.stream().map(facade -> facade.overridden).collect(Collectors.toList()).toArray(arr);
147	}
148
149	@Override
150	public String toString() {
151	StringBuilder sb = new StringBuilder("[");
152	if (size() == 0)
153	return sb.append("]").toString();
154	for (EqualsHashcodeOverridingFacade facade : innerSet) {
155	sb.append(facade.overridden.toString() + ",");
156	}
157	return sb.replace(sb.length() - 2, sb.length(), "]").toString();
158	}
159
160	private class EqualsHashcodeOverridingFacade implements Visitable {
161	private final N overridden;
162
163	EqualsHashcodeOverridingFacade(N overridden) {
164	this.overridden = overridden;
165	}
166
167	@Override
168	public <R, A> R accept(GenericVisitor<R, A> v, A arg) {
169	throw new AssertionError();
170	}
171
172	@Override
173	public <A> void accept(VoidVisitor<A> v, A arg) {
174	throw new AssertionError();
175	}
176
177	@Override
178	public final int hashCode() {
179	return overridden.accept(hashcodeVisitor, null);
180	}
181
182	@Override
183	public boolean equals(final Object obj) {
184	if (obj == null \|\| !(obj instanceof VisitorSet.EqualsHashcodeOverridingFacade)) {
185	return false;
186	}
187	return overridden.accept(equalsVisitor, ((EqualsHashcodeOverridingFacade) obj).overridden);
188	}
189	}
190
191	}
192