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.append(cursor.suffix(&()), &());
71 drop(cursor);
72 self.0 = new_tree;
73 removed
74 }
75
76 pub fn remove_range(&mut self, start: &impl MapSeekTarget<K>, end: &impl MapSeekTarget<K>) {
77 let start = MapSeekTargetAdaptor(start);
78 let end = MapSeekTargetAdaptor(end);
79 let mut cursor = self.0.cursor::<MapKeyRef<'_, K>>();
80 let mut new_tree = cursor.slice(&start, Bias::Left, &());
81 cursor.seek(&end, Bias::Left, &());
82 new_tree.append(cursor.suffix(&()), &());
83 drop(cursor);
84 self.0 = new_tree;
85 }
86
87 /// Returns the key-value pair with the greatest key less than or equal to the given key.
88 pub fn closest(&self, key: &K) -> Option<(&K, &V)> {
89 let mut cursor = self.0.cursor::<MapKeyRef<'_, K>>();
90 let key = MapKeyRef(Some(key));
91 cursor.seek(&key, Bias::Right, &());
92 cursor.prev(&());
93 cursor.item().map(|item| (&item.key, &item.value))
94 }
95
96 pub fn iter_from<'a>(&'a self, from: &'a K) -> impl Iterator<Item = (&K, &V)> + '_ {
97 let mut cursor = self.0.cursor::<MapKeyRef<'_, K>>();
98 let from_key = MapKeyRef(Some(from));
99 cursor.seek(&from_key, Bias::Left, &());
100
101 cursor
102 .into_iter()
103 .map(|map_entry| (&map_entry.key, &map_entry.value))
104 }
105
106 pub fn update<F, T>(&mut self, key: &K, f: F) -> Option<T>
107 where
108 F: FnOnce(&mut V) -> T,
109 {
110 let mut cursor = self.0.cursor::<MapKeyRef<'_, K>>();
111 let key = MapKeyRef(Some(key));
112 let mut new_tree = cursor.slice(&key, Bias::Left, &());
113 let mut result = None;
114 if key.cmp(&cursor.end(&()), &()) == Ordering::Equal {
115 let mut updated = cursor.item().unwrap().clone();
116 result = Some(f(&mut updated.value));
117 new_tree.push(updated, &());
118 cursor.next(&());
119 }
120 new_tree.append(cursor.suffix(&()), &());
121 drop(cursor);
122 self.0 = new_tree;
123 result
124 }
125
126 pub fn retain<F: FnMut(&K, &V) -> bool>(&mut self, mut predicate: F) {
127 let mut new_map = SumTree::<MapEntry<K, V>>::default();
128
129 let mut cursor = self.0.cursor::<MapKeyRef<'_, K>>();
130 cursor.next(&());
131 while let Some(item) = cursor.item() {
132 if predicate(&item.key, &item.value) {
133 new_map.push(item.clone(), &());
134 }
135 cursor.next(&());
136 }
137 drop(cursor);
138
139 self.0 = new_map;
140 }
141
142 pub fn iter(&self) -> impl Iterator<Item = (&K, &V)> + '_ {
143 self.0.iter().map(|entry| (&entry.key, &entry.value))
144 }
145
146 pub fn values(&self) -> impl Iterator<Item = &V> + '_ {
147 self.0.iter().map(|entry| &entry.value)
148 }
149
150 pub fn insert_tree(&mut self, other: TreeMap<K, V>) {
151 let edits = other
152 .iter()
153 .map(|(key, value)| {
154 Edit::Insert(MapEntry {
155 key: key.to_owned(),
156 value: value.to_owned(),
157 })
158 })
159 .collect();
160
161 self.0.edit(edits, &());
162 }
163}
164
165#[derive(Debug)]
166struct MapSeekTargetAdaptor<'a, T>(&'a T);
167
168impl<'a, K: Debug + Clone + Default + Ord, T: MapSeekTarget<K>>
169 SeekTarget<'a, MapKey<K>, MapKeyRef<'a, K>> for MapSeekTargetAdaptor<'_, T>
170{
171 fn cmp(&self, cursor_location: &MapKeyRef<K>, _: &()) -> Ordering {
172 if let Some(key) = &cursor_location.0 {
173 MapSeekTarget::cmp_cursor(self.0, key)
174 } else {
175 Ordering::Greater
176 }
177 }
178}
179
180pub trait MapSeekTarget<K>: Debug {
181 fn cmp_cursor(&self, cursor_location: &K) -> Ordering;
182}
183
184impl<K: Debug + Ord> MapSeekTarget<K> for K {
185 fn cmp_cursor(&self, cursor_location: &K) -> Ordering {
186 self.cmp(cursor_location)
187 }
188}
189
190impl<K, V> Default for TreeMap<K, V>
191where
192 K: Clone + Debug + Default + Ord,
193 V: Clone + Debug,
194{
195 fn default() -> Self {
196 Self(Default::default())
197 }
198}
199
200impl<K, V> Item for MapEntry<K, V>
201where
202 K: Clone + Debug + Default + Ord,
203 V: Clone,
204{
205 type Summary = MapKey<K>;
206
207 fn summary(&self) -> Self::Summary {
208 self.key()
209 }
210}
211
212impl<K, V> KeyedItem for MapEntry<K, V>
213where
214 K: Clone + Debug + Default + Ord,
215 V: Clone,
216{
217 type Key = MapKey<K>;
218
219 fn key(&self) -> Self::Key {
220 MapKey(self.key.clone())
221 }
222}
223
224impl<K> Summary for MapKey<K>
225where
226 K: Clone + Debug + Default,
227{
228 type Context = ();
229
230 fn add_summary(&mut self, summary: &Self, _: &()) {
231 *self = summary.clone()
232 }
233}
234
235impl<'a, K> Dimension<'a, MapKey<K>> for MapKeyRef<'a, K>
236where
237 K: Clone + Debug + Default + Ord,
238{
239 fn add_summary(&mut self, summary: &'a MapKey<K>, _: &()) {
240 self.0 = Some(&summary.0)
241 }
242}
243
244impl<'a, K> SeekTarget<'a, MapKey<K>, MapKeyRef<'a, K>> for MapKeyRef<'_, K>
245where
246 K: Clone + Debug + Default + Ord,
247{
248 fn cmp(&self, cursor_location: &MapKeyRef<K>, _: &()) -> Ordering {
249 Ord::cmp(&self.0, &cursor_location.0)
250 }
251}
252
253impl<K> Default for TreeSet<K>
254where
255 K: Clone + Debug + Default + Ord,
256{
257 fn default() -> Self {
258 Self(Default::default())
259 }
260}
261
262impl<K> TreeSet<K>
263where
264 K: Clone + Debug + Default + Ord,
265{
266 pub fn from_ordered_entries(entries: impl IntoIterator<Item = K>) -> Self {
267 Self(TreeMap::from_ordered_entries(
268 entries.into_iter().map(|key| (key, ())),
269 ))
270 }
271
272 pub fn insert(&mut self, key: K) {
273 self.0.insert(key, ());
274 }
275
276 pub fn contains(&self, key: &K) -> bool {
277 self.0.get(key).is_some()
278 }
279
280 pub fn iter(&self) -> impl Iterator<Item = &K> + '_ {
281 self.0.iter().map(|(k, _)| k)
282 }
283}
284
285#[cfg(test)]
286mod tests {
287 use super::*;
288
289 #[test]
290 fn test_basic() {
291 let mut map = TreeMap::default();
292 assert_eq!(map.iter().collect::<Vec<_>>(), vec![]);
293
294 map.insert(3, "c");
295 assert_eq!(map.get(&3), Some(&"c"));
296 assert_eq!(map.iter().collect::<Vec<_>>(), vec![(&3, &"c")]);
297
298 map.insert(1, "a");
299 assert_eq!(map.get(&1), Some(&"a"));
300 assert_eq!(map.iter().collect::<Vec<_>>(), vec![(&1, &"a"), (&3, &"c")]);
301
302 map.insert(2, "b");
303 assert_eq!(map.get(&2), Some(&"b"));
304 assert_eq!(map.get(&1), Some(&"a"));
305 assert_eq!(map.get(&3), Some(&"c"));
306 assert_eq!(
307 map.iter().collect::<Vec<_>>(),
308 vec![(&1, &"a"), (&2, &"b"), (&3, &"c")]
309 );
310
311 assert_eq!(map.closest(&0), None);
312 assert_eq!(map.closest(&1), Some((&1, &"a")));
313 assert_eq!(map.closest(&10), Some((&3, &"c")));
314
315 map.remove(&2);
316 assert_eq!(map.get(&2), None);
317 assert_eq!(map.iter().collect::<Vec<_>>(), vec![(&1, &"a"), (&3, &"c")]);
318
319 assert_eq!(map.closest(&2), Some((&1, &"a")));
320
321 map.remove(&3);
322 assert_eq!(map.get(&3), None);
323 assert_eq!(map.iter().collect::<Vec<_>>(), vec![(&1, &"a")]);
324
325 map.remove(&1);
326 assert_eq!(map.get(&1), None);
327 assert_eq!(map.iter().collect::<Vec<_>>(), vec![]);
328
329 map.insert(4, "d");
330 map.insert(5, "e");
331 map.insert(6, "f");
332 map.retain(|key, _| *key % 2 == 0);
333 assert_eq!(map.iter().collect::<Vec<_>>(), vec![(&4, &"d"), (&6, &"f")]);
334 }
335
336 #[test]
337 fn test_iter_from() {
338 let mut map = TreeMap::default();
339
340 map.insert("a", 1);
341 map.insert("b", 2);
342 map.insert("baa", 3);
343 map.insert("baaab", 4);
344 map.insert("c", 5);
345
346 let result = map
347 .iter_from(&"ba")
348 .take_while(|(key, _)| key.starts_with(&"ba"))
349 .collect::<Vec<_>>();
350
351 assert_eq!(result.len(), 2);
352 assert!(result.iter().find(|(k, _)| k == &&"baa").is_some());
353 assert!(result.iter().find(|(k, _)| k == &&"baaab").is_some());
354
355 let result = map
356 .iter_from(&"c")
357 .take_while(|(key, _)| key.starts_with(&"c"))
358 .collect::<Vec<_>>();
359
360 assert_eq!(result.len(), 1);
361 assert!(result.iter().find(|(k, _)| k == &&"c").is_some());
362 }
363
364 #[test]
365 fn test_insert_tree() {
366 let mut map = TreeMap::default();
367 map.insert("a", 1);
368 map.insert("b", 2);
369 map.insert("c", 3);
370
371 let mut other = TreeMap::default();
372 other.insert("a", 2);
373 other.insert("b", 2);
374 other.insert("d", 4);
375
376 map.insert_tree(other);
377
378 assert_eq!(map.iter().count(), 4);
379 assert_eq!(map.get(&"a"), Some(&2));
380 assert_eq!(map.get(&"b"), Some(&2));
381 assert_eq!(map.get(&"c"), Some(&3));
382 assert_eq!(map.get(&"d"), Some(&4));
383 }
384
385 #[test]
386 fn test_remove_between_and_path_successor() {
387 use std::path::{Path, PathBuf};
388
389 #[derive(Debug)]
390 pub struct PathDescendants<'a>(&'a Path);
391
392 impl MapSeekTarget<PathBuf> for PathDescendants<'_> {
393 fn cmp_cursor(&self, key: &PathBuf) -> Ordering {
394 if key.starts_with(&self.0) {
395 Ordering::Greater
396 } else {
397 self.0.cmp(key)
398 }
399 }
400 }
401
402 let mut map = TreeMap::default();
403
404 map.insert(PathBuf::from("a"), 1);
405 map.insert(PathBuf::from("a/a"), 1);
406 map.insert(PathBuf::from("b"), 2);
407 map.insert(PathBuf::from("b/a/a"), 3);
408 map.insert(PathBuf::from("b/a/a/a/b"), 4);
409 map.insert(PathBuf::from("c"), 5);
410 map.insert(PathBuf::from("c/a"), 6);
411
412 map.remove_range(
413 &PathBuf::from("b/a"),
414 &PathDescendants(&PathBuf::from("b/a")),
415 );
416
417 assert_eq!(map.get(&PathBuf::from("a")), Some(&1));
418 assert_eq!(map.get(&PathBuf::from("a/a")), Some(&1));
419 assert_eq!(map.get(&PathBuf::from("b")), Some(&2));
420 assert_eq!(map.get(&PathBuf::from("b/a/a")), None);
421 assert_eq!(map.get(&PathBuf::from("b/a/a/a/b")), None);
422 assert_eq!(map.get(&PathBuf::from("c")), Some(&5));
423 assert_eq!(map.get(&PathBuf::from("c/a")), Some(&6));
424
425 map.remove_range(&PathBuf::from("c"), &PathDescendants(&PathBuf::from("c")));
426
427 assert_eq!(map.get(&PathBuf::from("a")), Some(&1));
428 assert_eq!(map.get(&PathBuf::from("a/a")), Some(&1));
429 assert_eq!(map.get(&PathBuf::from("b")), Some(&2));
430 assert_eq!(map.get(&PathBuf::from("c")), None);
431 assert_eq!(map.get(&PathBuf::from("c/a")), None);
432
433 map.remove_range(&PathBuf::from("a"), &PathDescendants(&PathBuf::from("a")));
434
435 assert_eq!(map.get(&PathBuf::from("a")), None);
436 assert_eq!(map.get(&PathBuf::from("a/a")), None);
437 assert_eq!(map.get(&PathBuf::from("b")), Some(&2));
438
439 map.remove_range(&PathBuf::from("b"), &PathDescendants(&PathBuf::from("b")));
440
441 assert_eq!(map.get(&PathBuf::from("b")), None);
442 }
443}