1 //! `IndexMap` is a hash table where the iteration order of the key-value 2 //! pairs is independent of the hash values of the keys. 3 4 mod core; 5 6 pub use crate::mutable_keys::MutableKeys; 7 8 #[cfg(feature = "rayon")] 9 pub use crate::rayon::map as rayon; 10 11 use crate::vec::{self, Vec}; 12 use ::core::cmp::Ordering; 13 use ::core::fmt; 14 use ::core::hash::{BuildHasher, Hash, Hasher}; 15 use ::core::iter::FromIterator; 16 use ::core::ops::{Index, IndexMut, RangeBounds}; 17 use ::core::slice::{Iter as SliceIter, IterMut as SliceIterMut}; 18 19 #[cfg(has_std)] 20 use std::collections::hash_map::RandomState; 21 22 use self::core::IndexMapCore; 23 use crate::equivalent::Equivalent; 24 use crate::util::third; 25 use crate::{Bucket, Entries, HashValue}; 26 27 pub use self::core::{Entry, OccupiedEntry, VacantEntry}; 28 29 /// A hash table where the iteration order of the key-value pairs is independent 30 /// of the hash values of the keys. 31 /// 32 /// The interface is closely compatible with the standard `HashMap`, but also 33 /// has additional features. 34 /// 35 /// # Order 36 /// 37 /// The key-value pairs have a consistent order that is determined by 38 /// the sequence of insertion and removal calls on the map. The order does 39 /// not depend on the keys or the hash function at all. 40 /// 41 /// All iterators traverse the map in *the order*. 42 /// 43 /// The insertion order is preserved, with **notable exceptions** like the 44 /// `.remove()` or `.swap_remove()` methods. Methods such as `.sort_by()` of 45 /// course result in a new order, depending on the sorting order. 46 /// 47 /// # Indices 48 /// 49 /// The key-value pairs are indexed in a compact range without holes in the 50 /// range `0..self.len()`. For example, the method `.get_full` looks up the 51 /// index for a key, and the method `.get_index` looks up the key-value pair by 52 /// index. 53 /// 54 /// # Examples 55 /// 56 /// ``` 57 /// use indexmap::IndexMap; 58 /// 59 /// // count the frequency of each letter in a sentence. 60 /// let mut letters = IndexMap::new(); 61 /// for ch in "a short treatise on fungi".chars() { 62 /// *letters.entry(ch).or_insert(0) += 1; 63 /// } 64 /// 65 /// assert_eq!(letters[&'s'], 2); 66 /// assert_eq!(letters[&'t'], 3); 67 /// assert_eq!(letters[&'u'], 1); 68 /// assert_eq!(letters.get(&'y'), None); 69 /// ``` 70 #[cfg(has_std)] 71 pub struct IndexMap<K, V, S = RandomState> { 72 core: IndexMapCore<K, V>, 73 hash_builder: S, 74 } 75 #[cfg(not(has_std))] 76 pub struct IndexMap<K, V, S> { 77 core: IndexMapCore<K, V>, 78 hash_builder: S, 79 } 80 81 impl<K, V, S> Clone for IndexMap<K, V, S> 82 where 83 K: Clone, 84 V: Clone, 85 S: Clone, 86 { clone(&self) -> Self87 fn clone(&self) -> Self { 88 IndexMap { 89 core: self.core.clone(), 90 hash_builder: self.hash_builder.clone(), 91 } 92 } 93 clone_from(&mut self, other: &Self)94 fn clone_from(&mut self, other: &Self) { 95 self.core.clone_from(&other.core); 96 self.hash_builder.clone_from(&other.hash_builder); 97 } 98 } 99 100 impl<K, V, S> Entries for IndexMap<K, V, S> { 101 type Entry = Bucket<K, V>; 102 103 #[inline] into_entries(self) -> Vec<Self::Entry>104 fn into_entries(self) -> Vec<Self::Entry> { 105 self.core.into_entries() 106 } 107 108 #[inline] as_entries(&self) -> &[Self::Entry]109 fn as_entries(&self) -> &[Self::Entry] { 110 self.core.as_entries() 111 } 112 113 #[inline] as_entries_mut(&mut self) -> &mut [Self::Entry]114 fn as_entries_mut(&mut self) -> &mut [Self::Entry] { 115 self.core.as_entries_mut() 116 } 117 with_entries<F>(&mut self, f: F) where F: FnOnce(&mut [Self::Entry]),118 fn with_entries<F>(&mut self, f: F) 119 where 120 F: FnOnce(&mut [Self::Entry]), 121 { 122 self.core.with_entries(f); 123 } 124 } 125 126 impl<K, V, S> fmt::Debug for IndexMap<K, V, S> 127 where 128 K: fmt::Debug, 129 V: fmt::Debug, 130 { fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result131 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { 132 if cfg!(not(feature = "test_debug")) { 133 f.debug_map().entries(self.iter()).finish() 134 } else { 135 // Let the inner `IndexMapCore` print all of its details 136 f.debug_struct("IndexMap") 137 .field("core", &self.core) 138 .finish() 139 } 140 } 141 } 142 143 #[cfg(has_std)] 144 impl<K, V> IndexMap<K, V> { 145 /// Create a new map. (Does not allocate.) 146 #[inline] new() -> Self147 pub fn new() -> Self { 148 Self::with_capacity(0) 149 } 150 151 /// Create a new map with capacity for `n` key-value pairs. (Does not 152 /// allocate if `n` is zero.) 153 /// 154 /// Computes in **O(n)** time. 155 #[inline] with_capacity(n: usize) -> Self156 pub fn with_capacity(n: usize) -> Self { 157 Self::with_capacity_and_hasher(n, <_>::default()) 158 } 159 } 160 161 impl<K, V, S> IndexMap<K, V, S> { 162 /// Create a new map with capacity for `n` key-value pairs. (Does not 163 /// allocate if `n` is zero.) 164 /// 165 /// Computes in **O(n)** time. 166 #[inline] with_capacity_and_hasher(n: usize, hash_builder: S) -> Self167 pub fn with_capacity_and_hasher(n: usize, hash_builder: S) -> Self { 168 if n == 0 { 169 IndexMap { 170 core: IndexMapCore::new(), 171 hash_builder, 172 } 173 } else { 174 IndexMap { 175 core: IndexMapCore::with_capacity(n), 176 hash_builder, 177 } 178 } 179 } 180 181 /// Create a new map with `hash_builder` with_hasher(hash_builder: S) -> Self182 pub fn with_hasher(hash_builder: S) -> Self { 183 Self::with_capacity_and_hasher(0, hash_builder) 184 } 185 186 /// Computes in **O(1)** time. capacity(&self) -> usize187 pub fn capacity(&self) -> usize { 188 self.core.capacity() 189 } 190 191 /// Return a reference to the map's `BuildHasher`. hasher(&self) -> &S192 pub fn hasher(&self) -> &S { 193 &self.hash_builder 194 } 195 196 /// Return the number of key-value pairs in the map. 197 /// 198 /// Computes in **O(1)** time. 199 #[inline] len(&self) -> usize200 pub fn len(&self) -> usize { 201 self.core.len() 202 } 203 204 /// Returns true if the map contains no elements. 205 /// 206 /// Computes in **O(1)** time. 207 #[inline] is_empty(&self) -> bool208 pub fn is_empty(&self) -> bool { 209 self.len() == 0 210 } 211 212 /// Return an iterator over the key-value pairs of the map, in their order iter(&self) -> Iter<'_, K, V>213 pub fn iter(&self) -> Iter<'_, K, V> { 214 Iter { 215 iter: self.as_entries().iter(), 216 } 217 } 218 219 /// Return an iterator over the key-value pairs of the map, in their order iter_mut(&mut self) -> IterMut<'_, K, V>220 pub fn iter_mut(&mut self) -> IterMut<'_, K, V> { 221 IterMut { 222 iter: self.as_entries_mut().iter_mut(), 223 } 224 } 225 226 /// Return an iterator over the keys of the map, in their order keys(&self) -> Keys<'_, K, V>227 pub fn keys(&self) -> Keys<'_, K, V> { 228 Keys { 229 iter: self.as_entries().iter(), 230 } 231 } 232 233 /// Return an iterator over the values of the map, in their order values(&self) -> Values<'_, K, V>234 pub fn values(&self) -> Values<'_, K, V> { 235 Values { 236 iter: self.as_entries().iter(), 237 } 238 } 239 240 /// Return an iterator over mutable references to the the values of the map, 241 /// in their order values_mut(&mut self) -> ValuesMut<'_, K, V>242 pub fn values_mut(&mut self) -> ValuesMut<'_, K, V> { 243 ValuesMut { 244 iter: self.as_entries_mut().iter_mut(), 245 } 246 } 247 248 /// Remove all key-value pairs in the map, while preserving its capacity. 249 /// 250 /// Computes in **O(n)** time. clear(&mut self)251 pub fn clear(&mut self) { 252 self.core.clear(); 253 } 254 255 /// Shortens the map, keeping the first `len` elements and dropping the rest. 256 /// 257 /// If `len` is greater than the map's current length, this has no effect. truncate(&mut self, len: usize)258 pub fn truncate(&mut self, len: usize) { 259 self.core.truncate(len); 260 } 261 262 /// Clears the `IndexMap` in the given index range, returning those 263 /// key-value pairs as a drain iterator. 264 /// 265 /// The range may be any type that implements `RangeBounds<usize>`, 266 /// including all of the `std::ops::Range*` types, or even a tuple pair of 267 /// `Bound` start and end values. To drain the map entirely, use `RangeFull` 268 /// like `map.drain(..)`. 269 /// 270 /// This shifts down all entries following the drained range to fill the 271 /// gap, and keeps the allocated memory for reuse. 272 /// 273 /// ***Panics*** if the starting point is greater than the end point or if 274 /// the end point is greater than the length of the map. drain<R>(&mut self, range: R) -> Drain<'_, K, V> where R: RangeBounds<usize>,275 pub fn drain<R>(&mut self, range: R) -> Drain<'_, K, V> 276 where 277 R: RangeBounds<usize>, 278 { 279 Drain { 280 iter: self.core.drain(range), 281 } 282 } 283 284 /// Splits the collection into two at the given index. 285 /// 286 /// Returns a newly allocated map containing the elements in the range 287 /// `[at, len)`. After the call, the original map will be left containing 288 /// the elements `[0, at)` with its previous capacity unchanged. 289 /// 290 /// ***Panics*** if `at > len`. split_off(&mut self, at: usize) -> Self where S: Clone,291 pub fn split_off(&mut self, at: usize) -> Self 292 where 293 S: Clone, 294 { 295 Self { 296 core: self.core.split_off(at), 297 hash_builder: self.hash_builder.clone(), 298 } 299 } 300 } 301 302 impl<K, V, S> IndexMap<K, V, S> 303 where 304 K: Hash + Eq, 305 S: BuildHasher, 306 { 307 /// Reserve capacity for `additional` more key-value pairs. 308 /// 309 /// Computes in **O(n)** time. reserve(&mut self, additional: usize)310 pub fn reserve(&mut self, additional: usize) { 311 self.core.reserve(additional); 312 } 313 314 /// Shrink the capacity of the map as much as possible. 315 /// 316 /// Computes in **O(n)** time. shrink_to_fit(&mut self)317 pub fn shrink_to_fit(&mut self) { 318 self.core.shrink_to_fit(); 319 } 320 hash<Q: ?Sized + Hash>(&self, key: &Q) -> HashValue321 fn hash<Q: ?Sized + Hash>(&self, key: &Q) -> HashValue { 322 let mut h = self.hash_builder.build_hasher(); 323 key.hash(&mut h); 324 HashValue(h.finish() as usize) 325 } 326 327 /// Insert a key-value pair in the map. 328 /// 329 /// If an equivalent key already exists in the map: the key remains and 330 /// retains in its place in the order, its corresponding value is updated 331 /// with `value` and the older value is returned inside `Some(_)`. 332 /// 333 /// If no equivalent key existed in the map: the new key-value pair is 334 /// inserted, last in order, and `None` is returned. 335 /// 336 /// Computes in **O(1)** time (amortized average). 337 /// 338 /// See also [`entry`](#method.entry) if you you want to insert *or* modify 339 /// or if you need to get the index of the corresponding key-value pair. insert(&mut self, key: K, value: V) -> Option<V>340 pub fn insert(&mut self, key: K, value: V) -> Option<V> { 341 self.insert_full(key, value).1 342 } 343 344 /// Insert a key-value pair in the map, and get their index. 345 /// 346 /// If an equivalent key already exists in the map: the key remains and 347 /// retains in its place in the order, its corresponding value is updated 348 /// with `value` and the older value is returned inside `(index, Some(_))`. 349 /// 350 /// If no equivalent key existed in the map: the new key-value pair is 351 /// inserted, last in order, and `(index, None)` is returned. 352 /// 353 /// Computes in **O(1)** time (amortized average). 354 /// 355 /// See also [`entry`](#method.entry) if you you want to insert *or* modify 356 /// or if you need to get the index of the corresponding key-value pair. insert_full(&mut self, key: K, value: V) -> (usize, Option<V>)357 pub fn insert_full(&mut self, key: K, value: V) -> (usize, Option<V>) { 358 let hash = self.hash(&key); 359 self.core.insert_full(hash, key, value) 360 } 361 362 /// Get the given key’s corresponding entry in the map for insertion and/or 363 /// in-place manipulation. 364 /// 365 /// Computes in **O(1)** time (amortized average). entry(&mut self, key: K) -> Entry<'_, K, V>366 pub fn entry(&mut self, key: K) -> Entry<'_, K, V> { 367 let hash = self.hash(&key); 368 self.core.entry(hash, key) 369 } 370 371 /// Return `true` if an equivalent to `key` exists in the map. 372 /// 373 /// Computes in **O(1)** time (average). contains_key<Q: ?Sized>(&self, key: &Q) -> bool where Q: Hash + Equivalent<K>,374 pub fn contains_key<Q: ?Sized>(&self, key: &Q) -> bool 375 where 376 Q: Hash + Equivalent<K>, 377 { 378 self.get_index_of(key).is_some() 379 } 380 381 /// Return a reference to the value stored for `key`, if it is present, 382 /// else `None`. 383 /// 384 /// Computes in **O(1)** time (average). get<Q: ?Sized>(&self, key: &Q) -> Option<&V> where Q: Hash + Equivalent<K>,385 pub fn get<Q: ?Sized>(&self, key: &Q) -> Option<&V> 386 where 387 Q: Hash + Equivalent<K>, 388 { 389 if let Some(i) = self.get_index_of(key) { 390 let entry = &self.as_entries()[i]; 391 Some(&entry.value) 392 } else { 393 None 394 } 395 } 396 397 /// Return references to the key-value pair stored for `key`, 398 /// if it is present, else `None`. 399 /// 400 /// Computes in **O(1)** time (average). get_key_value<Q: ?Sized>(&self, key: &Q) -> Option<(&K, &V)> where Q: Hash + Equivalent<K>,401 pub fn get_key_value<Q: ?Sized>(&self, key: &Q) -> Option<(&K, &V)> 402 where 403 Q: Hash + Equivalent<K>, 404 { 405 if let Some(i) = self.get_index_of(key) { 406 let entry = &self.as_entries()[i]; 407 Some((&entry.key, &entry.value)) 408 } else { 409 None 410 } 411 } 412 413 /// Return item index, key and value get_full<Q: ?Sized>(&self, key: &Q) -> Option<(usize, &K, &V)> where Q: Hash + Equivalent<K>,414 pub fn get_full<Q: ?Sized>(&self, key: &Q) -> Option<(usize, &K, &V)> 415 where 416 Q: Hash + Equivalent<K>, 417 { 418 if let Some(i) = self.get_index_of(key) { 419 let entry = &self.as_entries()[i]; 420 Some((i, &entry.key, &entry.value)) 421 } else { 422 None 423 } 424 } 425 426 /// Return item index, if it exists in the map get_index_of<Q: ?Sized>(&self, key: &Q) -> Option<usize> where Q: Hash + Equivalent<K>,427 pub fn get_index_of<Q: ?Sized>(&self, key: &Q) -> Option<usize> 428 where 429 Q: Hash + Equivalent<K>, 430 { 431 if self.is_empty() { 432 None 433 } else { 434 let hash = self.hash(key); 435 self.core.get_index_of(hash, key) 436 } 437 } 438 get_mut<Q: ?Sized>(&mut self, key: &Q) -> Option<&mut V> where Q: Hash + Equivalent<K>,439 pub fn get_mut<Q: ?Sized>(&mut self, key: &Q) -> Option<&mut V> 440 where 441 Q: Hash + Equivalent<K>, 442 { 443 if let Some(i) = self.get_index_of(key) { 444 let entry = &mut self.as_entries_mut()[i]; 445 Some(&mut entry.value) 446 } else { 447 None 448 } 449 } 450 get_full_mut<Q: ?Sized>(&mut self, key: &Q) -> Option<(usize, &K, &mut V)> where Q: Hash + Equivalent<K>,451 pub fn get_full_mut<Q: ?Sized>(&mut self, key: &Q) -> Option<(usize, &K, &mut V)> 452 where 453 Q: Hash + Equivalent<K>, 454 { 455 if let Some(i) = self.get_index_of(key) { 456 let entry = &mut self.as_entries_mut()[i]; 457 Some((i, &entry.key, &mut entry.value)) 458 } else { 459 None 460 } 461 } 462 get_full_mut2_impl<Q: ?Sized>( &mut self, key: &Q, ) -> Option<(usize, &mut K, &mut V)> where Q: Hash + Equivalent<K>,463 pub(crate) fn get_full_mut2_impl<Q: ?Sized>( 464 &mut self, 465 key: &Q, 466 ) -> Option<(usize, &mut K, &mut V)> 467 where 468 Q: Hash + Equivalent<K>, 469 { 470 if let Some(i) = self.get_index_of(key) { 471 let entry = &mut self.as_entries_mut()[i]; 472 Some((i, &mut entry.key, &mut entry.value)) 473 } else { 474 None 475 } 476 } 477 478 /// Remove the key-value pair equivalent to `key` and return 479 /// its value. 480 /// 481 /// **NOTE:** This is equivalent to `.swap_remove(key)`, if you need to 482 /// preserve the order of the keys in the map, use `.shift_remove(key)` 483 /// instead. 484 /// 485 /// Computes in **O(1)** time (average). remove<Q: ?Sized>(&mut self, key: &Q) -> Option<V> where Q: Hash + Equivalent<K>,486 pub fn remove<Q: ?Sized>(&mut self, key: &Q) -> Option<V> 487 where 488 Q: Hash + Equivalent<K>, 489 { 490 self.swap_remove(key) 491 } 492 493 /// Remove and return the key-value pair equivalent to `key`. 494 /// 495 /// **NOTE:** This is equivalent to `.swap_remove_entry(key)`, if you need to 496 /// preserve the order of the keys in the map, use `.shift_remove_entry(key)` 497 /// instead. 498 /// 499 /// Computes in **O(1)** time (average). remove_entry<Q: ?Sized>(&mut self, key: &Q) -> Option<(K, V)> where Q: Hash + Equivalent<K>,500 pub fn remove_entry<Q: ?Sized>(&mut self, key: &Q) -> Option<(K, V)> 501 where 502 Q: Hash + Equivalent<K>, 503 { 504 self.swap_remove_entry(key) 505 } 506 507 /// Remove the key-value pair equivalent to `key` and return 508 /// its value. 509 /// 510 /// Like `Vec::swap_remove`, the pair is removed by swapping it with the 511 /// last element of the map and popping it off. **This perturbs 512 /// the postion of what used to be the last element!** 513 /// 514 /// Return `None` if `key` is not in map. 515 /// 516 /// Computes in **O(1)** time (average). swap_remove<Q: ?Sized>(&mut self, key: &Q) -> Option<V> where Q: Hash + Equivalent<K>,517 pub fn swap_remove<Q: ?Sized>(&mut self, key: &Q) -> Option<V> 518 where 519 Q: Hash + Equivalent<K>, 520 { 521 self.swap_remove_full(key).map(third) 522 } 523 524 /// Remove and return the key-value pair equivalent to `key`. 525 /// 526 /// Like `Vec::swap_remove`, the pair is removed by swapping it with the 527 /// last element of the map and popping it off. **This perturbs 528 /// the postion of what used to be the last element!** 529 /// 530 /// Return `None` if `key` is not in map. 531 /// 532 /// Computes in **O(1)** time (average). swap_remove_entry<Q: ?Sized>(&mut self, key: &Q) -> Option<(K, V)> where Q: Hash + Equivalent<K>,533 pub fn swap_remove_entry<Q: ?Sized>(&mut self, key: &Q) -> Option<(K, V)> 534 where 535 Q: Hash + Equivalent<K>, 536 { 537 match self.swap_remove_full(key) { 538 Some((_, key, value)) => Some((key, value)), 539 None => None, 540 } 541 } 542 543 /// Remove the key-value pair equivalent to `key` and return it and 544 /// the index it had. 545 /// 546 /// Like `Vec::swap_remove`, the pair is removed by swapping it with the 547 /// last element of the map and popping it off. **This perturbs 548 /// the postion of what used to be the last element!** 549 /// 550 /// Return `None` if `key` is not in map. 551 /// 552 /// Computes in **O(1)** time (average). swap_remove_full<Q: ?Sized>(&mut self, key: &Q) -> Option<(usize, K, V)> where Q: Hash + Equivalent<K>,553 pub fn swap_remove_full<Q: ?Sized>(&mut self, key: &Q) -> Option<(usize, K, V)> 554 where 555 Q: Hash + Equivalent<K>, 556 { 557 if self.is_empty() { 558 return None; 559 } 560 let hash = self.hash(key); 561 self.core.swap_remove_full(hash, key) 562 } 563 564 /// Remove the key-value pair equivalent to `key` and return 565 /// its value. 566 /// 567 /// Like `Vec::remove`, the pair is removed by shifting all of the 568 /// elements that follow it, preserving their relative order. 569 /// **This perturbs the index of all of those elements!** 570 /// 571 /// Return `None` if `key` is not in map. 572 /// 573 /// Computes in **O(n)** time (average). shift_remove<Q: ?Sized>(&mut self, key: &Q) -> Option<V> where Q: Hash + Equivalent<K>,574 pub fn shift_remove<Q: ?Sized>(&mut self, key: &Q) -> Option<V> 575 where 576 Q: Hash + Equivalent<K>, 577 { 578 self.shift_remove_full(key).map(third) 579 } 580 581 /// Remove and return the key-value pair equivalent to `key`. 582 /// 583 /// Like `Vec::remove`, the pair is removed by shifting all of the 584 /// elements that follow it, preserving their relative order. 585 /// **This perturbs the index of all of those elements!** 586 /// 587 /// Return `None` if `key` is not in map. 588 /// 589 /// Computes in **O(n)** time (average). shift_remove_entry<Q: ?Sized>(&mut self, key: &Q) -> Option<(K, V)> where Q: Hash + Equivalent<K>,590 pub fn shift_remove_entry<Q: ?Sized>(&mut self, key: &Q) -> Option<(K, V)> 591 where 592 Q: Hash + Equivalent<K>, 593 { 594 match self.shift_remove_full(key) { 595 Some((_, key, value)) => Some((key, value)), 596 None => None, 597 } 598 } 599 600 /// Remove the key-value pair equivalent to `key` and return it and 601 /// the index it had. 602 /// 603 /// Like `Vec::remove`, the pair is removed by shifting all of the 604 /// elements that follow it, preserving their relative order. 605 /// **This perturbs the index of all of those elements!** 606 /// 607 /// Return `None` if `key` is not in map. 608 /// 609 /// Computes in **O(n)** time (average). shift_remove_full<Q: ?Sized>(&mut self, key: &Q) -> Option<(usize, K, V)> where Q: Hash + Equivalent<K>,610 pub fn shift_remove_full<Q: ?Sized>(&mut self, key: &Q) -> Option<(usize, K, V)> 611 where 612 Q: Hash + Equivalent<K>, 613 { 614 if self.is_empty() { 615 return None; 616 } 617 let hash = self.hash(key); 618 self.core.shift_remove_full(hash, key) 619 } 620 621 /// Remove the last key-value pair 622 /// 623 /// Computes in **O(1)** time (average). pop(&mut self) -> Option<(K, V)>624 pub fn pop(&mut self) -> Option<(K, V)> { 625 self.core.pop() 626 } 627 628 /// Scan through each key-value pair in the map and keep those where the 629 /// closure `keep` returns `true`. 630 /// 631 /// The elements are visited in order, and remaining elements keep their 632 /// order. 633 /// 634 /// Computes in **O(n)** time (average). retain<F>(&mut self, mut keep: F) where F: FnMut(&K, &mut V) -> bool,635 pub fn retain<F>(&mut self, mut keep: F) 636 where 637 F: FnMut(&K, &mut V) -> bool, 638 { 639 self.core.retain_in_order(move |k, v| keep(k, v)); 640 } 641 retain_mut<F>(&mut self, keep: F) where F: FnMut(&mut K, &mut V) -> bool,642 pub(crate) fn retain_mut<F>(&mut self, keep: F) 643 where 644 F: FnMut(&mut K, &mut V) -> bool, 645 { 646 self.core.retain_in_order(keep); 647 } 648 649 /// Sort the map’s key-value pairs by the default ordering of the keys. 650 /// 651 /// See `sort_by` for details. sort_keys(&mut self) where K: Ord,652 pub fn sort_keys(&mut self) 653 where 654 K: Ord, 655 { 656 self.with_entries(|entries| { 657 entries.sort_by(|a, b| Ord::cmp(&a.key, &b.key)); 658 }); 659 } 660 661 /// Sort the map’s key-value pairs in place using the comparison 662 /// function `compare`. 663 /// 664 /// The comparison function receives two key and value pairs to compare (you 665 /// can sort by keys or values or their combination as needed). 666 /// 667 /// Computes in **O(n log n + c)** time and **O(n)** space where *n* is 668 /// the length of the map and *c* the capacity. The sort is stable. sort_by<F>(&mut self, mut cmp: F) where F: FnMut(&K, &V, &K, &V) -> Ordering,669 pub fn sort_by<F>(&mut self, mut cmp: F) 670 where 671 F: FnMut(&K, &V, &K, &V) -> Ordering, 672 { 673 self.with_entries(move |entries| { 674 entries.sort_by(move |a, b| cmp(&a.key, &a.value, &b.key, &b.value)); 675 }); 676 } 677 678 /// Sort the key-value pairs of the map and return a by value iterator of 679 /// the key-value pairs with the result. 680 /// 681 /// The sort is stable. sorted_by<F>(self, mut cmp: F) -> IntoIter<K, V> where F: FnMut(&K, &V, &K, &V) -> Ordering,682 pub fn sorted_by<F>(self, mut cmp: F) -> IntoIter<K, V> 683 where 684 F: FnMut(&K, &V, &K, &V) -> Ordering, 685 { 686 let mut entries = self.into_entries(); 687 entries.sort_by(move |a, b| cmp(&a.key, &a.value, &b.key, &b.value)); 688 IntoIter { 689 iter: entries.into_iter(), 690 } 691 } 692 693 /// Reverses the order of the map’s key-value pairs in place. 694 /// 695 /// Computes in **O(n)** time and **O(1)** space. reverse(&mut self)696 pub fn reverse(&mut self) { 697 self.core.reverse() 698 } 699 } 700 701 impl<K, V, S> IndexMap<K, V, S> { 702 /// Get a key-value pair by index 703 /// 704 /// Valid indices are *0 <= index < self.len()* 705 /// 706 /// Computes in **O(1)** time. get_index(&self, index: usize) -> Option<(&K, &V)>707 pub fn get_index(&self, index: usize) -> Option<(&K, &V)> { 708 self.as_entries().get(index).map(Bucket::refs) 709 } 710 711 /// Get a key-value pair by index 712 /// 713 /// Valid indices are *0 <= index < self.len()* 714 /// 715 /// Computes in **O(1)** time. get_index_mut(&mut self, index: usize) -> Option<(&mut K, &mut V)>716 pub fn get_index_mut(&mut self, index: usize) -> Option<(&mut K, &mut V)> { 717 self.as_entries_mut().get_mut(index).map(Bucket::muts) 718 } 719 720 /// Get the first key-value pair 721 /// 722 /// Computes in **O(1)** time. first(&self) -> Option<(&K, &V)>723 pub fn first(&self) -> Option<(&K, &V)> { 724 self.as_entries().first().map(Bucket::refs) 725 } 726 727 /// Get the first key-value pair, with mutable access to the value 728 /// 729 /// Computes in **O(1)** time. first_mut(&mut self) -> Option<(&K, &mut V)>730 pub fn first_mut(&mut self) -> Option<(&K, &mut V)> { 731 self.as_entries_mut().first_mut().map(Bucket::ref_mut) 732 } 733 734 /// Get the last key-value pair 735 /// 736 /// Computes in **O(1)** time. last(&self) -> Option<(&K, &V)>737 pub fn last(&self) -> Option<(&K, &V)> { 738 self.as_entries().last().map(Bucket::refs) 739 } 740 741 /// Get the last key-value pair, with mutable access to the value 742 /// 743 /// Computes in **O(1)** time. last_mut(&mut self) -> Option<(&K, &mut V)>744 pub fn last_mut(&mut self) -> Option<(&K, &mut V)> { 745 self.as_entries_mut().last_mut().map(Bucket::ref_mut) 746 } 747 748 /// Remove the key-value pair by index 749 /// 750 /// Valid indices are *0 <= index < self.len()* 751 /// 752 /// Like `Vec::swap_remove`, the pair is removed by swapping it with the 753 /// last element of the map and popping it off. **This perturbs 754 /// the postion of what used to be the last element!** 755 /// 756 /// Computes in **O(1)** time (average). swap_remove_index(&mut self, index: usize) -> Option<(K, V)>757 pub fn swap_remove_index(&mut self, index: usize) -> Option<(K, V)> { 758 self.core.swap_remove_index(index) 759 } 760 761 /// Remove the key-value pair by index 762 /// 763 /// Valid indices are *0 <= index < self.len()* 764 /// 765 /// Like `Vec::remove`, the pair is removed by shifting all of the 766 /// elements that follow it, preserving their relative order. 767 /// **This perturbs the index of all of those elements!** 768 /// 769 /// Computes in **O(n)** time (average). shift_remove_index(&mut self, index: usize) -> Option<(K, V)>770 pub fn shift_remove_index(&mut self, index: usize) -> Option<(K, V)> { 771 self.core.shift_remove_index(index) 772 } 773 774 /// Swaps the position of two key-value pairs in the map. 775 /// 776 /// ***Panics*** if `a` or `b` are out of bounds. swap_indices(&mut self, a: usize, b: usize)777 pub fn swap_indices(&mut self, a: usize, b: usize) { 778 self.core.swap_indices(a, b) 779 } 780 } 781 782 /// An iterator over the keys of a `IndexMap`. 783 /// 784 /// This `struct` is created by the [`keys`] method on [`IndexMap`]. See its 785 /// documentation for more. 786 /// 787 /// [`keys`]: struct.IndexMap.html#method.keys 788 /// [`IndexMap`]: struct.IndexMap.html 789 pub struct Keys<'a, K, V> { 790 pub(crate) iter: SliceIter<'a, Bucket<K, V>>, 791 } 792 793 impl<'a, K, V> Iterator for Keys<'a, K, V> { 794 type Item = &'a K; 795 796 iterator_methods!(Bucket::key_ref); 797 } 798 799 impl<K, V> DoubleEndedIterator for Keys<'_, K, V> { next_back(&mut self) -> Option<Self::Item>800 fn next_back(&mut self) -> Option<Self::Item> { 801 self.iter.next_back().map(Bucket::key_ref) 802 } 803 } 804 805 impl<K, V> ExactSizeIterator for Keys<'_, K, V> { len(&self) -> usize806 fn len(&self) -> usize { 807 self.iter.len() 808 } 809 } 810 811 // FIXME(#26925) Remove in favor of `#[derive(Clone)]` 812 impl<K, V> Clone for Keys<'_, K, V> { clone(&self) -> Self813 fn clone(&self) -> Self { 814 Keys { 815 iter: self.iter.clone(), 816 } 817 } 818 } 819 820 impl<K: fmt::Debug, V> fmt::Debug for Keys<'_, K, V> { fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result821 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { 822 f.debug_list().entries(self.clone()).finish() 823 } 824 } 825 826 /// An iterator over the values of a `IndexMap`. 827 /// 828 /// This `struct` is created by the [`values`] method on [`IndexMap`]. See its 829 /// documentation for more. 830 /// 831 /// [`values`]: struct.IndexMap.html#method.values 832 /// [`IndexMap`]: struct.IndexMap.html 833 pub struct Values<'a, K, V> { 834 iter: SliceIter<'a, Bucket<K, V>>, 835 } 836 837 impl<'a, K, V> Iterator for Values<'a, K, V> { 838 type Item = &'a V; 839 840 iterator_methods!(Bucket::value_ref); 841 } 842 843 impl<K, V> DoubleEndedIterator for Values<'_, K, V> { next_back(&mut self) -> Option<Self::Item>844 fn next_back(&mut self) -> Option<Self::Item> { 845 self.iter.next_back().map(Bucket::value_ref) 846 } 847 } 848 849 impl<K, V> ExactSizeIterator for Values<'_, K, V> { len(&self) -> usize850 fn len(&self) -> usize { 851 self.iter.len() 852 } 853 } 854 855 // FIXME(#26925) Remove in favor of `#[derive(Clone)]` 856 impl<K, V> Clone for Values<'_, K, V> { clone(&self) -> Self857 fn clone(&self) -> Self { 858 Values { 859 iter: self.iter.clone(), 860 } 861 } 862 } 863 864 impl<K, V: fmt::Debug> fmt::Debug for Values<'_, K, V> { fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result865 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { 866 f.debug_list().entries(self.clone()).finish() 867 } 868 } 869 870 /// A mutable iterator over the values of a `IndexMap`. 871 /// 872 /// This `struct` is created by the [`values_mut`] method on [`IndexMap`]. See its 873 /// documentation for more. 874 /// 875 /// [`values_mut`]: struct.IndexMap.html#method.values_mut 876 /// [`IndexMap`]: struct.IndexMap.html 877 pub struct ValuesMut<'a, K, V> { 878 iter: SliceIterMut<'a, Bucket<K, V>>, 879 } 880 881 impl<'a, K, V> Iterator for ValuesMut<'a, K, V> { 882 type Item = &'a mut V; 883 884 iterator_methods!(Bucket::value_mut); 885 } 886 887 impl<K, V> DoubleEndedIterator for ValuesMut<'_, K, V> { next_back(&mut self) -> Option<Self::Item>888 fn next_back(&mut self) -> Option<Self::Item> { 889 self.iter.next_back().map(Bucket::value_mut) 890 } 891 } 892 893 impl<K, V> ExactSizeIterator for ValuesMut<'_, K, V> { len(&self) -> usize894 fn len(&self) -> usize { 895 self.iter.len() 896 } 897 } 898 899 /// An iterator over the entries of a `IndexMap`. 900 /// 901 /// This `struct` is created by the [`iter`] method on [`IndexMap`]. See its 902 /// documentation for more. 903 /// 904 /// [`iter`]: struct.IndexMap.html#method.iter 905 /// [`IndexMap`]: struct.IndexMap.html 906 pub struct Iter<'a, K, V> { 907 iter: SliceIter<'a, Bucket<K, V>>, 908 } 909 910 impl<'a, K, V> Iterator for Iter<'a, K, V> { 911 type Item = (&'a K, &'a V); 912 913 iterator_methods!(Bucket::refs); 914 } 915 916 impl<K, V> DoubleEndedIterator for Iter<'_, K, V> { next_back(&mut self) -> Option<Self::Item>917 fn next_back(&mut self) -> Option<Self::Item> { 918 self.iter.next_back().map(Bucket::refs) 919 } 920 } 921 922 impl<K, V> ExactSizeIterator for Iter<'_, K, V> { len(&self) -> usize923 fn len(&self) -> usize { 924 self.iter.len() 925 } 926 } 927 928 // FIXME(#26925) Remove in favor of `#[derive(Clone)]` 929 impl<K, V> Clone for Iter<'_, K, V> { clone(&self) -> Self930 fn clone(&self) -> Self { 931 Iter { 932 iter: self.iter.clone(), 933 } 934 } 935 } 936 937 impl<K: fmt::Debug, V: fmt::Debug> fmt::Debug for Iter<'_, K, V> { fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result938 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { 939 f.debug_list().entries(self.clone()).finish() 940 } 941 } 942 943 /// A mutable iterator over the entries of a `IndexMap`. 944 /// 945 /// This `struct` is created by the [`iter_mut`] method on [`IndexMap`]. See its 946 /// documentation for more. 947 /// 948 /// [`iter_mut`]: struct.IndexMap.html#method.iter_mut 949 /// [`IndexMap`]: struct.IndexMap.html 950 pub struct IterMut<'a, K, V> { 951 iter: SliceIterMut<'a, Bucket<K, V>>, 952 } 953 954 impl<'a, K, V> Iterator for IterMut<'a, K, V> { 955 type Item = (&'a K, &'a mut V); 956 957 iterator_methods!(Bucket::ref_mut); 958 } 959 960 impl<K, V> DoubleEndedIterator for IterMut<'_, K, V> { next_back(&mut self) -> Option<Self::Item>961 fn next_back(&mut self) -> Option<Self::Item> { 962 self.iter.next_back().map(Bucket::ref_mut) 963 } 964 } 965 966 impl<K, V> ExactSizeIterator for IterMut<'_, K, V> { len(&self) -> usize967 fn len(&self) -> usize { 968 self.iter.len() 969 } 970 } 971 972 /// An owning iterator over the entries of a `IndexMap`. 973 /// 974 /// This `struct` is created by the [`into_iter`] method on [`IndexMap`] 975 /// (provided by the `IntoIterator` trait). See its documentation for more. 976 /// 977 /// [`into_iter`]: struct.IndexMap.html#method.into_iter 978 /// [`IndexMap`]: struct.IndexMap.html 979 pub struct IntoIter<K, V> { 980 pub(crate) iter: vec::IntoIter<Bucket<K, V>>, 981 } 982 983 impl<K, V> Iterator for IntoIter<K, V> { 984 type Item = (K, V); 985 986 iterator_methods!(Bucket::key_value); 987 } 988 989 impl<K, V> DoubleEndedIterator for IntoIter<K, V> { next_back(&mut self) -> Option<Self::Item>990 fn next_back(&mut self) -> Option<Self::Item> { 991 self.iter.next_back().map(Bucket::key_value) 992 } 993 } 994 995 impl<K, V> ExactSizeIterator for IntoIter<K, V> { len(&self) -> usize996 fn len(&self) -> usize { 997 self.iter.len() 998 } 999 } 1000 1001 impl<K: fmt::Debug, V: fmt::Debug> fmt::Debug for IntoIter<K, V> { fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result1002 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { 1003 let iter = self.iter.as_slice().iter().map(Bucket::refs); 1004 f.debug_list().entries(iter).finish() 1005 } 1006 } 1007 1008 /// A draining iterator over the entries of a `IndexMap`. 1009 /// 1010 /// This `struct` is created by the [`drain`] method on [`IndexMap`]. See its 1011 /// documentation for more. 1012 /// 1013 /// [`drain`]: struct.IndexMap.html#method.drain 1014 /// [`IndexMap`]: struct.IndexMap.html 1015 pub struct Drain<'a, K, V> { 1016 pub(crate) iter: vec::Drain<'a, Bucket<K, V>>, 1017 } 1018 1019 impl<K, V> Iterator for Drain<'_, K, V> { 1020 type Item = (K, V); 1021 1022 iterator_methods!(Bucket::key_value); 1023 } 1024 1025 impl<K, V> DoubleEndedIterator for Drain<'_, K, V> { 1026 double_ended_iterator_methods!(Bucket::key_value); 1027 } 1028 1029 impl<'a, K, V, S> IntoIterator for &'a IndexMap<K, V, S> { 1030 type Item = (&'a K, &'a V); 1031 type IntoIter = Iter<'a, K, V>; into_iter(self) -> Self::IntoIter1032 fn into_iter(self) -> Self::IntoIter { 1033 self.iter() 1034 } 1035 } 1036 1037 impl<'a, K, V, S> IntoIterator for &'a mut IndexMap<K, V, S> { 1038 type Item = (&'a K, &'a mut V); 1039 type IntoIter = IterMut<'a, K, V>; into_iter(self) -> Self::IntoIter1040 fn into_iter(self) -> Self::IntoIter { 1041 self.iter_mut() 1042 } 1043 } 1044 1045 impl<K, V, S> IntoIterator for IndexMap<K, V, S> { 1046 type Item = (K, V); 1047 type IntoIter = IntoIter<K, V>; into_iter(self) -> Self::IntoIter1048 fn into_iter(self) -> Self::IntoIter { 1049 IntoIter { 1050 iter: self.into_entries().into_iter(), 1051 } 1052 } 1053 } 1054 1055 /// Access `IndexMap` values corresponding to a key. 1056 /// 1057 /// # Examples 1058 /// 1059 /// ``` 1060 /// use indexmap::IndexMap; 1061 /// 1062 /// let mut map = IndexMap::new(); 1063 /// for word in "Lorem ipsum dolor sit amet".split_whitespace() { 1064 /// map.insert(word.to_lowercase(), word.to_uppercase()); 1065 /// } 1066 /// assert_eq!(map["lorem"], "LOREM"); 1067 /// assert_eq!(map["ipsum"], "IPSUM"); 1068 /// ``` 1069 /// 1070 /// ```should_panic 1071 /// use indexmap::IndexMap; 1072 /// 1073 /// let mut map = IndexMap::new(); 1074 /// map.insert("foo", 1); 1075 /// println!("{:?}", map["bar"]); // panics! 1076 /// ``` 1077 impl<K, V, Q: ?Sized, S> Index<&Q> for IndexMap<K, V, S> 1078 where 1079 Q: Hash + Equivalent<K>, 1080 K: Hash + Eq, 1081 S: BuildHasher, 1082 { 1083 type Output = V; 1084 1085 /// Returns a reference to the value corresponding to the supplied `key`. 1086 /// 1087 /// ***Panics*** if `key` is not present in the map. index(&self, key: &Q) -> &V1088 fn index(&self, key: &Q) -> &V { 1089 self.get(key).expect("IndexMap: key not found") 1090 } 1091 } 1092 1093 /// Access `IndexMap` values corresponding to a key. 1094 /// 1095 /// Mutable indexing allows changing / updating values of key-value 1096 /// pairs that are already present. 1097 /// 1098 /// You can **not** insert new pairs with index syntax, use `.insert()`. 1099 /// 1100 /// # Examples 1101 /// 1102 /// ``` 1103 /// use indexmap::IndexMap; 1104 /// 1105 /// let mut map = IndexMap::new(); 1106 /// for word in "Lorem ipsum dolor sit amet".split_whitespace() { 1107 /// map.insert(word.to_lowercase(), word.to_string()); 1108 /// } 1109 /// let lorem = &mut map["lorem"]; 1110 /// assert_eq!(lorem, "Lorem"); 1111 /// lorem.retain(char::is_lowercase); 1112 /// assert_eq!(map["lorem"], "orem"); 1113 /// ``` 1114 /// 1115 /// ```should_panic 1116 /// use indexmap::IndexMap; 1117 /// 1118 /// let mut map = IndexMap::new(); 1119 /// map.insert("foo", 1); 1120 /// map["bar"] = 1; // panics! 1121 /// ``` 1122 impl<K, V, Q: ?Sized, S> IndexMut<&Q> for IndexMap<K, V, S> 1123 where 1124 Q: Hash + Equivalent<K>, 1125 K: Hash + Eq, 1126 S: BuildHasher, 1127 { 1128 /// Returns a mutable reference to the value corresponding to the supplied `key`. 1129 /// 1130 /// ***Panics*** if `key` is not present in the map. index_mut(&mut self, key: &Q) -> &mut V1131 fn index_mut(&mut self, key: &Q) -> &mut V { 1132 self.get_mut(key).expect("IndexMap: key not found") 1133 } 1134 } 1135 1136 /// Access `IndexMap` values at indexed positions. 1137 /// 1138 /// # Examples 1139 /// 1140 /// ``` 1141 /// use indexmap::IndexMap; 1142 /// 1143 /// let mut map = IndexMap::new(); 1144 /// for word in "Lorem ipsum dolor sit amet".split_whitespace() { 1145 /// map.insert(word.to_lowercase(), word.to_uppercase()); 1146 /// } 1147 /// assert_eq!(map[0], "LOREM"); 1148 /// assert_eq!(map[1], "IPSUM"); 1149 /// map.reverse(); 1150 /// assert_eq!(map[0], "AMET"); 1151 /// assert_eq!(map[1], "SIT"); 1152 /// map.sort_keys(); 1153 /// assert_eq!(map[0], "AMET"); 1154 /// assert_eq!(map[1], "DOLOR"); 1155 /// ``` 1156 /// 1157 /// ```should_panic 1158 /// use indexmap::IndexMap; 1159 /// 1160 /// let mut map = IndexMap::new(); 1161 /// map.insert("foo", 1); 1162 /// println!("{:?}", map[10]); // panics! 1163 /// ``` 1164 impl<K, V, S> Index<usize> for IndexMap<K, V, S> { 1165 type Output = V; 1166 1167 /// Returns a reference to the value at the supplied `index`. 1168 /// 1169 /// ***Panics*** if `index` is out of bounds. index(&self, index: usize) -> &V1170 fn index(&self, index: usize) -> &V { 1171 self.get_index(index) 1172 .expect("IndexMap: index out of bounds") 1173 .1 1174 } 1175 } 1176 1177 /// Access `IndexMap` values at indexed positions. 1178 /// 1179 /// Mutable indexing allows changing / updating indexed values 1180 /// that are already present. 1181 /// 1182 /// You can **not** insert new values with index syntax, use `.insert()`. 1183 /// 1184 /// # Examples 1185 /// 1186 /// ``` 1187 /// use indexmap::IndexMap; 1188 /// 1189 /// let mut map = IndexMap::new(); 1190 /// for word in "Lorem ipsum dolor sit amet".split_whitespace() { 1191 /// map.insert(word.to_lowercase(), word.to_string()); 1192 /// } 1193 /// let lorem = &mut map[0]; 1194 /// assert_eq!(lorem, "Lorem"); 1195 /// lorem.retain(char::is_lowercase); 1196 /// assert_eq!(map["lorem"], "orem"); 1197 /// ``` 1198 /// 1199 /// ```should_panic 1200 /// use indexmap::IndexMap; 1201 /// 1202 /// let mut map = IndexMap::new(); 1203 /// map.insert("foo", 1); 1204 /// map[10] = 1; // panics! 1205 /// ``` 1206 impl<K, V, S> IndexMut<usize> for IndexMap<K, V, S> { 1207 /// Returns a mutable reference to the value at the supplied `index`. 1208 /// 1209 /// ***Panics*** if `index` is out of bounds. index_mut(&mut self, index: usize) -> &mut V1210 fn index_mut(&mut self, index: usize) -> &mut V { 1211 self.get_index_mut(index) 1212 .expect("IndexMap: index out of bounds") 1213 .1 1214 } 1215 } 1216 1217 impl<K, V, S> FromIterator<(K, V)> for IndexMap<K, V, S> 1218 where 1219 K: Hash + Eq, 1220 S: BuildHasher + Default, 1221 { 1222 /// Create an `IndexMap` from the sequence of key-value pairs in the 1223 /// iterable. 1224 /// 1225 /// `from_iter` uses the same logic as `extend`. See 1226 /// [`extend`](#method.extend) for more details. from_iter<I: IntoIterator<Item = (K, V)>>(iterable: I) -> Self1227 fn from_iter<I: IntoIterator<Item = (K, V)>>(iterable: I) -> Self { 1228 let iter = iterable.into_iter(); 1229 let (low, _) = iter.size_hint(); 1230 let mut map = Self::with_capacity_and_hasher(low, <_>::default()); 1231 map.extend(iter); 1232 map 1233 } 1234 } 1235 1236 impl<K, V, S> Extend<(K, V)> for IndexMap<K, V, S> 1237 where 1238 K: Hash + Eq, 1239 S: BuildHasher, 1240 { 1241 /// Extend the map with all key-value pairs in the iterable. 1242 /// 1243 /// This is equivalent to calling [`insert`](#method.insert) for each of 1244 /// them in order, which means that for keys that already existed 1245 /// in the map, their value is updated but it keeps the existing order. 1246 /// 1247 /// New keys are inserted in the order they appear in the sequence. If 1248 /// equivalents of a key occur more than once, the last corresponding value 1249 /// prevails. extend<I: IntoIterator<Item = (K, V)>>(&mut self, iterable: I)1250 fn extend<I: IntoIterator<Item = (K, V)>>(&mut self, iterable: I) { 1251 // (Note: this is a copy of `std`/`hashbrown`'s reservation logic.) 1252 // Keys may be already present or show multiple times in the iterator. 1253 // Reserve the entire hint lower bound if the map is empty. 1254 // Otherwise reserve half the hint (rounded up), so the map 1255 // will only resize twice in the worst case. 1256 let iter = iterable.into_iter(); 1257 let reserve = if self.is_empty() { 1258 iter.size_hint().0 1259 } else { 1260 (iter.size_hint().0 + 1) / 2 1261 }; 1262 self.reserve(reserve); 1263 iter.for_each(move |(k, v)| { 1264 self.insert(k, v); 1265 }); 1266 } 1267 } 1268 1269 impl<'a, K, V, S> Extend<(&'a K, &'a V)> for IndexMap<K, V, S> 1270 where 1271 K: Hash + Eq + Copy, 1272 V: Copy, 1273 S: BuildHasher, 1274 { 1275 /// Extend the map with all key-value pairs in the iterable. 1276 /// 1277 /// See the first extend method for more details. extend<I: IntoIterator<Item = (&'a K, &'a V)>>(&mut self, iterable: I)1278 fn extend<I: IntoIterator<Item = (&'a K, &'a V)>>(&mut self, iterable: I) { 1279 self.extend(iterable.into_iter().map(|(&key, &value)| (key, value))); 1280 } 1281 } 1282 1283 impl<K, V, S> Default for IndexMap<K, V, S> 1284 where 1285 S: Default, 1286 { 1287 /// Return an empty `IndexMap` default() -> Self1288 fn default() -> Self { 1289 Self::with_capacity_and_hasher(0, S::default()) 1290 } 1291 } 1292 1293 impl<K, V1, S1, V2, S2> PartialEq<IndexMap<K, V2, S2>> for IndexMap<K, V1, S1> 1294 where 1295 K: Hash + Eq, 1296 V1: PartialEq<V2>, 1297 S1: BuildHasher, 1298 S2: BuildHasher, 1299 { eq(&self, other: &IndexMap<K, V2, S2>) -> bool1300 fn eq(&self, other: &IndexMap<K, V2, S2>) -> bool { 1301 if self.len() != other.len() { 1302 return false; 1303 } 1304 1305 self.iter() 1306 .all(|(key, value)| other.get(key).map_or(false, |v| *value == *v)) 1307 } 1308 } 1309 1310 impl<K, V, S> Eq for IndexMap<K, V, S> 1311 where 1312 K: Eq + Hash, 1313 V: Eq, 1314 S: BuildHasher, 1315 { 1316 } 1317 1318 #[cfg(test)] 1319 mod tests { 1320 use super::*; 1321 use crate::util::enumerate; 1322 use std::string::String; 1323 1324 #[test] it_works()1325 fn it_works() { 1326 let mut map = IndexMap::new(); 1327 assert_eq!(map.is_empty(), true); 1328 map.insert(1, ()); 1329 map.insert(1, ()); 1330 assert_eq!(map.len(), 1); 1331 assert!(map.get(&1).is_some()); 1332 assert_eq!(map.is_empty(), false); 1333 } 1334 1335 #[test] new()1336 fn new() { 1337 let map = IndexMap::<String, String>::new(); 1338 println!("{:?}", map); 1339 assert_eq!(map.capacity(), 0); 1340 assert_eq!(map.len(), 0); 1341 assert_eq!(map.is_empty(), true); 1342 } 1343 1344 #[test] insert()1345 fn insert() { 1346 let insert = [0, 4, 2, 12, 8, 7, 11, 5]; 1347 let not_present = [1, 3, 6, 9, 10]; 1348 let mut map = IndexMap::with_capacity(insert.len()); 1349 1350 for (i, &elt) in enumerate(&insert) { 1351 assert_eq!(map.len(), i); 1352 map.insert(elt, elt); 1353 assert_eq!(map.len(), i + 1); 1354 assert_eq!(map.get(&elt), Some(&elt)); 1355 assert_eq!(map[&elt], elt); 1356 } 1357 println!("{:?}", map); 1358 1359 for &elt in ¬_present { 1360 assert!(map.get(&elt).is_none()); 1361 } 1362 } 1363 1364 #[test] insert_full()1365 fn insert_full() { 1366 let insert = vec![9, 2, 7, 1, 4, 6, 13]; 1367 let present = vec![1, 6, 2]; 1368 let mut map = IndexMap::with_capacity(insert.len()); 1369 1370 for (i, &elt) in enumerate(&insert) { 1371 assert_eq!(map.len(), i); 1372 let (index, existing) = map.insert_full(elt, elt); 1373 assert_eq!(existing, None); 1374 assert_eq!(Some(index), map.get_full(&elt).map(|x| x.0)); 1375 assert_eq!(map.len(), i + 1); 1376 } 1377 1378 let len = map.len(); 1379 for &elt in &present { 1380 let (index, existing) = map.insert_full(elt, elt); 1381 assert_eq!(existing, Some(elt)); 1382 assert_eq!(Some(index), map.get_full(&elt).map(|x| x.0)); 1383 assert_eq!(map.len(), len); 1384 } 1385 } 1386 1387 #[test] insert_2()1388 fn insert_2() { 1389 let mut map = IndexMap::with_capacity(16); 1390 1391 let mut keys = vec![]; 1392 keys.extend(0..16); 1393 keys.extend(128..267); 1394 1395 for &i in &keys { 1396 let old_map = map.clone(); 1397 map.insert(i, ()); 1398 for key in old_map.keys() { 1399 if map.get(key).is_none() { 1400 println!("old_map: {:?}", old_map); 1401 println!("map: {:?}", map); 1402 panic!("did not find {} in map", key); 1403 } 1404 } 1405 } 1406 1407 for &i in &keys { 1408 assert!(map.get(&i).is_some(), "did not find {}", i); 1409 } 1410 } 1411 1412 #[test] insert_order()1413 fn insert_order() { 1414 let insert = [0, 4, 2, 12, 8, 7, 11, 5, 3, 17, 19, 22, 23]; 1415 let mut map = IndexMap::new(); 1416 1417 for &elt in &insert { 1418 map.insert(elt, ()); 1419 } 1420 1421 assert_eq!(map.keys().count(), map.len()); 1422 assert_eq!(map.keys().count(), insert.len()); 1423 for (a, b) in insert.iter().zip(map.keys()) { 1424 assert_eq!(a, b); 1425 } 1426 for (i, k) in (0..insert.len()).zip(map.keys()) { 1427 assert_eq!(map.get_index(i).unwrap().0, k); 1428 } 1429 } 1430 1431 #[test] grow()1432 fn grow() { 1433 let insert = [0, 4, 2, 12, 8, 7, 11]; 1434 let not_present = [1, 3, 6, 9, 10]; 1435 let mut map = IndexMap::with_capacity(insert.len()); 1436 1437 for (i, &elt) in enumerate(&insert) { 1438 assert_eq!(map.len(), i); 1439 map.insert(elt, elt); 1440 assert_eq!(map.len(), i + 1); 1441 assert_eq!(map.get(&elt), Some(&elt)); 1442 assert_eq!(map[&elt], elt); 1443 } 1444 1445 println!("{:?}", map); 1446 for &elt in &insert { 1447 map.insert(elt * 10, elt); 1448 } 1449 for &elt in &insert { 1450 map.insert(elt * 100, elt); 1451 } 1452 for (i, &elt) in insert.iter().cycle().enumerate().take(100) { 1453 map.insert(elt * 100 + i as i32, elt); 1454 } 1455 println!("{:?}", map); 1456 for &elt in ¬_present { 1457 assert!(map.get(&elt).is_none()); 1458 } 1459 } 1460 1461 #[test] reserve()1462 fn reserve() { 1463 let mut map = IndexMap::<usize, usize>::new(); 1464 assert_eq!(map.capacity(), 0); 1465 map.reserve(100); 1466 let capacity = map.capacity(); 1467 assert!(capacity >= 100); 1468 for i in 0..capacity { 1469 assert_eq!(map.len(), i); 1470 map.insert(i, i * i); 1471 assert_eq!(map.len(), i + 1); 1472 assert_eq!(map.capacity(), capacity); 1473 assert_eq!(map.get(&i), Some(&(i * i))); 1474 } 1475 map.insert(capacity, std::usize::MAX); 1476 assert_eq!(map.len(), capacity + 1); 1477 assert!(map.capacity() > capacity); 1478 assert_eq!(map.get(&capacity), Some(&std::usize::MAX)); 1479 } 1480 1481 #[test] shrink_to_fit()1482 fn shrink_to_fit() { 1483 let mut map = IndexMap::<usize, usize>::new(); 1484 assert_eq!(map.capacity(), 0); 1485 for i in 0..100 { 1486 assert_eq!(map.len(), i); 1487 map.insert(i, i * i); 1488 assert_eq!(map.len(), i + 1); 1489 assert!(map.capacity() >= i + 1); 1490 assert_eq!(map.get(&i), Some(&(i * i))); 1491 map.shrink_to_fit(); 1492 assert_eq!(map.len(), i + 1); 1493 assert_eq!(map.capacity(), i + 1); 1494 assert_eq!(map.get(&i), Some(&(i * i))); 1495 } 1496 } 1497 1498 #[test] remove()1499 fn remove() { 1500 let insert = [0, 4, 2, 12, 8, 7, 11, 5, 3, 17, 19, 22, 23]; 1501 let mut map = IndexMap::new(); 1502 1503 for &elt in &insert { 1504 map.insert(elt, elt); 1505 } 1506 1507 assert_eq!(map.keys().count(), map.len()); 1508 assert_eq!(map.keys().count(), insert.len()); 1509 for (a, b) in insert.iter().zip(map.keys()) { 1510 assert_eq!(a, b); 1511 } 1512 1513 let remove_fail = [99, 77]; 1514 let remove = [4, 12, 8, 7]; 1515 1516 for &key in &remove_fail { 1517 assert!(map.swap_remove_full(&key).is_none()); 1518 } 1519 println!("{:?}", map); 1520 for &key in &remove { 1521 //println!("{:?}", map); 1522 let index = map.get_full(&key).unwrap().0; 1523 assert_eq!(map.swap_remove_full(&key), Some((index, key, key))); 1524 } 1525 println!("{:?}", map); 1526 1527 for key in &insert { 1528 assert_eq!(map.get(key).is_some(), !remove.contains(key)); 1529 } 1530 assert_eq!(map.len(), insert.len() - remove.len()); 1531 assert_eq!(map.keys().count(), insert.len() - remove.len()); 1532 } 1533 1534 #[test] remove_to_empty()1535 fn remove_to_empty() { 1536 let mut map = indexmap! { 0 => 0, 4 => 4, 5 => 5 }; 1537 map.swap_remove(&5).unwrap(); 1538 map.swap_remove(&4).unwrap(); 1539 map.swap_remove(&0).unwrap(); 1540 assert!(map.is_empty()); 1541 } 1542 1543 #[test] swap_remove_index()1544 fn swap_remove_index() { 1545 let insert = [0, 4, 2, 12, 8, 7, 11, 5, 3, 17, 19, 22, 23]; 1546 let mut map = IndexMap::new(); 1547 1548 for &elt in &insert { 1549 map.insert(elt, elt * 2); 1550 } 1551 1552 let mut vector = insert.to_vec(); 1553 let remove_sequence = &[3, 3, 10, 4, 5, 4, 3, 0, 1]; 1554 1555 // check that the same swap remove sequence on vec and map 1556 // have the same result. 1557 for &rm in remove_sequence { 1558 let out_vec = vector.swap_remove(rm); 1559 let (out_map, _) = map.swap_remove_index(rm).unwrap(); 1560 assert_eq!(out_vec, out_map); 1561 } 1562 assert_eq!(vector.len(), map.len()); 1563 for (a, b) in vector.iter().zip(map.keys()) { 1564 assert_eq!(a, b); 1565 } 1566 } 1567 1568 #[test] partial_eq_and_eq()1569 fn partial_eq_and_eq() { 1570 let mut map_a = IndexMap::new(); 1571 map_a.insert(1, "1"); 1572 map_a.insert(2, "2"); 1573 let mut map_b = map_a.clone(); 1574 assert_eq!(map_a, map_b); 1575 map_b.swap_remove(&1); 1576 assert_ne!(map_a, map_b); 1577 1578 let map_c: IndexMap<_, String> = map_b.into_iter().map(|(k, v)| (k, v.into())).collect(); 1579 assert_ne!(map_a, map_c); 1580 assert_ne!(map_c, map_a); 1581 } 1582 1583 #[test] extend()1584 fn extend() { 1585 let mut map = IndexMap::new(); 1586 map.extend(vec![(&1, &2), (&3, &4)]); 1587 map.extend(vec![(5, 6)]); 1588 assert_eq!( 1589 map.into_iter().collect::<Vec<_>>(), 1590 vec![(1, 2), (3, 4), (5, 6)] 1591 ); 1592 } 1593 1594 #[test] entry()1595 fn entry() { 1596 let mut map = IndexMap::new(); 1597 1598 map.insert(1, "1"); 1599 map.insert(2, "2"); 1600 { 1601 let e = map.entry(3); 1602 assert_eq!(e.index(), 2); 1603 let e = e.or_insert("3"); 1604 assert_eq!(e, &"3"); 1605 } 1606 1607 let e = map.entry(2); 1608 assert_eq!(e.index(), 1); 1609 assert_eq!(e.key(), &2); 1610 match e { 1611 Entry::Occupied(ref e) => assert_eq!(e.get(), &"2"), 1612 Entry::Vacant(_) => panic!(), 1613 } 1614 assert_eq!(e.or_insert("4"), &"2"); 1615 } 1616 1617 #[test] entry_and_modify()1618 fn entry_and_modify() { 1619 let mut map = IndexMap::new(); 1620 1621 map.insert(1, "1"); 1622 map.entry(1).and_modify(|x| *x = "2"); 1623 assert_eq!(Some(&"2"), map.get(&1)); 1624 1625 map.entry(2).and_modify(|x| *x = "doesn't exist"); 1626 assert_eq!(None, map.get(&2)); 1627 } 1628 1629 #[test] entry_or_default()1630 fn entry_or_default() { 1631 let mut map = IndexMap::new(); 1632 1633 #[derive(Debug, PartialEq)] 1634 enum TestEnum { 1635 DefaultValue, 1636 NonDefaultValue, 1637 } 1638 1639 impl Default for TestEnum { 1640 fn default() -> Self { 1641 TestEnum::DefaultValue 1642 } 1643 } 1644 1645 map.insert(1, TestEnum::NonDefaultValue); 1646 assert_eq!(&mut TestEnum::NonDefaultValue, map.entry(1).or_default()); 1647 1648 assert_eq!(&mut TestEnum::DefaultValue, map.entry(2).or_default()); 1649 } 1650 1651 #[test] keys()1652 fn keys() { 1653 let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')]; 1654 let map: IndexMap<_, _> = vec.into_iter().collect(); 1655 let keys: Vec<_> = map.keys().cloned().collect(); 1656 assert_eq!(keys.len(), 3); 1657 assert!(keys.contains(&1)); 1658 assert!(keys.contains(&2)); 1659 assert!(keys.contains(&3)); 1660 } 1661 1662 #[test] values()1663 fn values() { 1664 let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')]; 1665 let map: IndexMap<_, _> = vec.into_iter().collect(); 1666 let values: Vec<_> = map.values().cloned().collect(); 1667 assert_eq!(values.len(), 3); 1668 assert!(values.contains(&'a')); 1669 assert!(values.contains(&'b')); 1670 assert!(values.contains(&'c')); 1671 } 1672 1673 #[test] values_mut()1674 fn values_mut() { 1675 let vec = vec![(1, 1), (2, 2), (3, 3)]; 1676 let mut map: IndexMap<_, _> = vec.into_iter().collect(); 1677 for value in map.values_mut() { 1678 *value *= 2 1679 } 1680 let values: Vec<_> = map.values().cloned().collect(); 1681 assert_eq!(values.len(), 3); 1682 assert!(values.contains(&2)); 1683 assert!(values.contains(&4)); 1684 assert!(values.contains(&6)); 1685 } 1686 } 1687