1use std::{cmp::Ordering, fmt::Debug};
2
3use crate::{Bias, Dimension, Edit, Item, KeyedItem, SeekTarget, SumTree, Summary};
4
5#[derive(Clone, Debug, PartialEq, Eq)]
6pub struct TreeMap<K, V>(SumTree<MapEntry<K, V>>)
7where
8 K: Clone + Debug + Default + Ord,
9 V: Clone + Debug;
10
11#[derive(Clone, Debug, PartialEq, Eq)]
12pub struct MapEntry<K, V> {
13 key: K,
14 value: V,
15}
16
17#[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
18pub struct MapKey<K>(K);
19
20#[derive(Clone, Debug, Default)]
21pub struct MapKeyRef<'a, K>(Option<&'a K>);
22
23#[derive(Clone)]
24pub struct TreeSet<K>(TreeMap<K, ()>)
25where
26 K: Clone + Debug + Default + Ord;
27
28impl<K: Clone + Debug + Default + Ord, V: Clone + Debug> TreeMap<K, V> {
29 pub fn from_ordered_entries(entries: impl IntoIterator<Item = (K, V)>) -> Self {
30 let tree = SumTree::from_iter(
31 entries
32 .into_iter()
33 .map(|(key, value)| MapEntry { key, value }),
34 &(),
35 );
36 Self(tree)
37 }
38
39 pub fn is_empty(&self) -> bool {
40 self.0.is_empty()
41 }
42
43 pub fn get<'a>(&self, key: &'a K) -> Option<&V> {
44 let mut cursor = self.0.cursor::<MapKeyRef<'_, K>>();
45 cursor.seek(&MapKeyRef(Some(key)), Bias::Left, &());
46 if let Some(item) = cursor.item() {
47 if *key == item.key().0 {
48 Some(&item.value)
49 } else {
50 None
51 }
52 } else {
53 None
54 }
55 }
56
57 pub fn insert(&mut self, key: K, value: V) {
58 self.0.insert_or_replace(MapEntry { key, value }, &());
59 }
60
61 pub fn remove(&mut self, key: &K) -> Option<V> {
62 let mut removed = None;
63 let mut cursor = self.0.cursor::<MapKeyRef<'_, K>>();
64 let key = MapKeyRef(Some(key));
65 let mut new_tree = cursor.slice(&key, Bias::Left, &());
66 if key.cmp(&cursor.end(&()), &()) == Ordering::Equal {
67 removed = Some(cursor.item().unwrap().value.clone());
68 cursor.next(&());
69 }
70 new_tree.push_tree(cursor.suffix(&()), &());
71 drop(cursor);
72 self.0 = new_tree;
73 removed
74 }
75
76 /// Returns the key-value pair with the greatest key less than or equal to the given key.
77 pub fn closest(&self, key: &K) -> Option<(&K, &V)> {
78 let mut cursor = self.0.cursor::<MapKeyRef<'_, K>>();
79 let key = MapKeyRef(Some(key));
80 cursor.seek(&key, Bias::Right, &());
81 cursor.prev(&());
82 cursor.item().map(|item| (&item.key, &item.value))
83 }
84
85 pub fn remove_between(&mut self, from: &K, until: &K) {
86 let mut cursor = self.0.cursor::<MapKeyRef<'_, K>>();
87 let from_key = MapKeyRef(Some(from));
88 let mut new_tree = cursor.slice(&from_key, Bias::Left, &());
89 let until_key = MapKeyRef(Some(until));
90 cursor.seek_forward(&until_key, Bias::Left, &());
91 new_tree.push_tree(cursor.suffix(&()), &());
92 drop(cursor);
93 self.0 = new_tree;
94 }
95
96 pub fn remove_from_while<F>(&mut self, from: &K, mut f: F)
97 where
98 F: FnMut(&K, &V) -> bool,
99 {
100 let mut cursor = self.0.cursor::<MapKeyRef<'_, K>>();
101 let from_key = MapKeyRef(Some(from));
102 let mut new_tree = cursor.slice(&from_key, Bias::Left, &());
103 while let Some(item) = cursor.item() {
104 if !f(&item.key, &item.value) {
105 break;
106 }
107 cursor.next(&());
108 }
109 new_tree.push_tree(cursor.suffix(&()), &());
110 drop(cursor);
111 self.0 = new_tree;
112 }
113
114 pub fn update<F, T>(&mut self, key: &K, f: F) -> Option<T>
115 where
116 F: FnOnce(&mut V) -> T,
117 {
118 let mut cursor = self.0.cursor::<MapKeyRef<'_, K>>();
119 let key = MapKeyRef(Some(key));
120 let mut new_tree = cursor.slice(&key, Bias::Left, &());
121 let mut result = None;
122 if key.cmp(&cursor.end(&()), &()) == Ordering::Equal {
123 let mut updated = cursor.item().unwrap().clone();
124 result = Some(f(&mut updated.value));
125 new_tree.push(updated, &());
126 cursor.next(&());
127 }
128 new_tree.push_tree(cursor.suffix(&()), &());
129 drop(cursor);
130 self.0 = new_tree;
131 result
132 }
133
134 pub fn retain<F: FnMut(&K, &V) -> bool>(&mut self, mut predicate: F) {
135 let mut new_map = SumTree::<MapEntry<K, V>>::default();
136
137 let mut cursor = self.0.cursor::<MapKeyRef<'_, K>>();
138 cursor.next(&());
139 while let Some(item) = cursor.item() {
140 if predicate(&item.key, &item.value) {
141 new_map.push(item.clone(), &());
142 }
143 cursor.next(&());
144 }
145 drop(cursor);
146
147 self.0 = new_map;
148 }
149
150 pub fn iter(&self) -> impl Iterator<Item = (&K, &V)> + '_ {
151 self.0.iter().map(|entry| (&entry.key, &entry.value))
152 }
153
154 pub fn values(&self) -> impl Iterator<Item = &V> + '_ {
155 self.0.iter().map(|entry| &entry.value)
156 }
157
158 pub fn insert_tree(&mut self, other: TreeMap<K, V>) {
159 let edits = other
160 .iter()
161 .map(|(key, value)| {
162 Edit::Insert(MapEntry {
163 key: key.to_owned(),
164 value: value.to_owned(),
165 })
166 })
167 .collect();
168
169 self.0.edit(edits, &());
170 }
171}
172
173impl<K, V> Default for TreeMap<K, V>
174where
175 K: Clone + Debug + Default + Ord,
176 V: Clone + Debug,
177{
178 fn default() -> Self {
179 Self(Default::default())
180 }
181}
182
183impl<K, V> Item for MapEntry<K, V>
184where
185 K: Clone + Debug + Default + Ord,
186 V: Clone,
187{
188 type Summary = MapKey<K>;
189
190 fn summary(&self) -> Self::Summary {
191 self.key()
192 }
193}
194
195impl<K, V> KeyedItem for MapEntry<K, V>
196where
197 K: Clone + Debug + Default + Ord,
198 V: Clone,
199{
200 type Key = MapKey<K>;
201
202 fn key(&self) -> Self::Key {
203 MapKey(self.key.clone())
204 }
205}
206
207impl<K> Summary for MapKey<K>
208where
209 K: Clone + Debug + Default,
210{
211 type Context = ();
212
213 fn add_summary(&mut self, summary: &Self, _: &()) {
214 *self = summary.clone()
215 }
216}
217
218impl<'a, K> Dimension<'a, MapKey<K>> for MapKeyRef<'a, K>
219where
220 K: Clone + Debug + Default + Ord,
221{
222 fn add_summary(&mut self, summary: &'a MapKey<K>, _: &()) {
223 self.0 = Some(&summary.0)
224 }
225}
226
227impl<'a, K> SeekTarget<'a, MapKey<K>, MapKeyRef<'a, K>> for MapKeyRef<'_, K>
228where
229 K: Clone + Debug + Default + Ord,
230{
231 fn cmp(&self, cursor_location: &MapKeyRef<K>, _: &()) -> Ordering {
232 self.0.cmp(&cursor_location.0)
233 }
234}
235
236impl<K> Default for TreeSet<K>
237where
238 K: Clone + Debug + Default + Ord,
239{
240 fn default() -> Self {
241 Self(Default::default())
242 }
243}
244
245impl<K> TreeSet<K>
246where
247 K: Clone + Debug + Default + Ord,
248{
249 pub fn from_ordered_entries(entries: impl IntoIterator<Item = K>) -> Self {
250 Self(TreeMap::from_ordered_entries(
251 entries.into_iter().map(|key| (key, ())),
252 ))
253 }
254
255 pub fn insert(&mut self, key: K) {
256 self.0.insert(key, ());
257 }
258
259 pub fn contains(&self, key: &K) -> bool {
260 self.0.get(key).is_some()
261 }
262
263 pub fn iter(&self) -> impl Iterator<Item = &K> + '_ {
264 self.0.iter().map(|(k, _)| k)
265 }
266}
267
268#[cfg(test)]
269mod tests {
270 use super::*;
271
272 #[test]
273 fn test_basic() {
274 let mut map = TreeMap::default();
275 assert_eq!(map.iter().collect::<Vec<_>>(), vec![]);
276
277 map.insert(3, "c");
278 assert_eq!(map.get(&3), Some(&"c"));
279 assert_eq!(map.iter().collect::<Vec<_>>(), vec![(&3, &"c")]);
280
281 map.insert(1, "a");
282 assert_eq!(map.get(&1), Some(&"a"));
283 assert_eq!(map.iter().collect::<Vec<_>>(), vec![(&1, &"a"), (&3, &"c")]);
284
285 map.insert(2, "b");
286 assert_eq!(map.get(&2), Some(&"b"));
287 assert_eq!(map.get(&1), Some(&"a"));
288 assert_eq!(map.get(&3), Some(&"c"));
289 assert_eq!(
290 map.iter().collect::<Vec<_>>(),
291 vec![(&1, &"a"), (&2, &"b"), (&3, &"c")]
292 );
293
294 assert_eq!(map.closest(&0), None);
295 assert_eq!(map.closest(&1), Some((&1, &"a")));
296 assert_eq!(map.closest(&10), Some((&3, &"c")));
297
298 map.remove(&2);
299 assert_eq!(map.get(&2), None);
300 assert_eq!(map.iter().collect::<Vec<_>>(), vec![(&1, &"a"), (&3, &"c")]);
301
302 assert_eq!(map.closest(&2), Some((&1, &"a")));
303
304 map.remove(&3);
305 assert_eq!(map.get(&3), None);
306 assert_eq!(map.iter().collect::<Vec<_>>(), vec![(&1, &"a")]);
307
308 map.remove(&1);
309 assert_eq!(map.get(&1), None);
310 assert_eq!(map.iter().collect::<Vec<_>>(), vec![]);
311
312 map.insert(4, "d");
313 map.insert(5, "e");
314 map.insert(6, "f");
315 map.retain(|key, _| *key % 2 == 0);
316 assert_eq!(map.iter().collect::<Vec<_>>(), vec![(&4, &"d"), (&6, &"f")]);
317 }
318
319 #[test]
320 fn test_remove_between() {
321 let mut map = TreeMap::default();
322
323 map.insert("a", 1);
324 map.insert("b", 2);
325 map.insert("baa", 3);
326 map.insert("baaab", 4);
327 map.insert("c", 5);
328
329 map.remove_between(&"ba", &"bb");
330
331 assert_eq!(map.get(&"a"), Some(&1));
332 assert_eq!(map.get(&"b"), Some(&2));
333 assert_eq!(map.get(&"baaa"), None);
334 assert_eq!(map.get(&"baaaab"), None);
335 assert_eq!(map.get(&"c"), Some(&5));
336 }
337
338 #[test]
339 fn test_remove_from_while() {
340 let mut map = TreeMap::default();
341
342 map.insert("a", 1);
343 map.insert("b", 2);
344 map.insert("baa", 3);
345 map.insert("baaab", 4);
346 map.insert("c", 5);
347
348 map.remove_from_while(&"ba", |key, _| key.starts_with(&"ba"));
349
350 assert_eq!(map.get(&"a"), Some(&1));
351 assert_eq!(map.get(&"b"), Some(&2));
352 assert_eq!(map.get(&"baaa"), None);
353 assert_eq!(map.get(&"baaaab"), None);
354 assert_eq!(map.get(&"c"), Some(&5));
355 }
356
357 #[test]
358 fn test_insert_tree() {
359 let mut map = TreeMap::default();
360 map.insert("a", 1);
361 map.insert("b", 2);
362 map.insert("c", 3);
363
364 let mut other = TreeMap::default();
365 other.insert("a", 2);
366 other.insert("b", 2);
367 other.insert("d", 4);
368
369 map.insert_tree(other);
370
371 assert_eq!(map.iter().count(), 4);
372 assert_eq!(map.get(&"a"), Some(&2));
373 assert_eq!(map.get(&"b"), Some(&2));
374 assert_eq!(map.get(&"c"), Some(&3));
375 assert_eq!(map.get(&"d"), Some(&4));
376 }
377}