2 * (C) Copyright 2016 Pantheon Technologies, s.r.o. and others.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
16 package org.opendaylight.yangtools.triemap;
18 import java.util.AbstractMap.SimpleImmutableEntry;
19 import java.util.Iterator;
20 import java.util.Map.Entry;
21 import java.util.NoSuchElementException;
22 import java.util.Optional;
25 * Mimic immutable ListMap in Scala
27 * @author Roman Levenstein <romixlev@gmail.com>
31 final class ListMap<K, V> {
35 // Modified during remove0 only
36 private ListMap<K, V> next;
38 private ListMap(final K k, final V v) {
42 private ListMap(final K k, final V v, final ListMap<K, V> next) {
48 static <K,V> ListMap<K, V> map(final K k1, final V v1, final K k2, final V v2) {
49 return new ListMap<>(k1, v1, new ListMap<>(k2, v2));
54 for (ListMap<?, ?> wlk = next; wlk != null; wlk = wlk.next) {
60 Optional<V> get(final K key) {
62 return Optional.of(v);
65 // We do not perform recursion on purpose here, so we do not run out of stack if the key hashing fails.
66 for (ListMap<K, V> m = next; m != null; m = m.next) {
67 if (key.equals(m.k)) {
68 return Optional.of(m.v);
72 return Optional.empty();
75 ListMap<K,V> add(final K key, final V value) {
76 return new ListMap<>(key, value, remove(key));
79 ListMap<K, V> remove(final K key) {
87 private boolean contains(final K key) {
92 // We do not perform recursion on purpose here, so we do not run out of stack if the key hashing fails.
93 for (ListMap<K, V> m = next; m != null; m = m.next) {
94 if (key.equals(m.k)) {
102 private ListMap<K, V> remove0(final K key) {
103 ListMap<K, V> n = this;
104 ListMap<K, V> ret = null;
105 ListMap<K, V> lastN = null;
107 if (key.equals(n.k)) {
113 lastN.next = new ListMap<>(n.k, n.v);
116 ret = new ListMap<>(n.k, n.v);
124 Iterator<Entry<K, V>> iterator() {
125 return new NodeIterator<>(this);
128 static final class NodeIterator<K,V> implements Iterator<Entry<K, V>> {
129 private ListMap<K, V> n;
131 NodeIterator(final ListMap<K, V> n) {
136 public boolean hasNext() {
141 public Entry<K, V> next() {
143 throw new NoSuchElementException();
146 final Entry<K, V> res = new SimpleImmutableEntry<>(n.k, n.v);