1 // Copyright 2013 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! An ordered map and set implemented as self-balancing binary search
12 //! trees. The only requirement for the types is that the key implements
17 use alloc::owned::Box;
18 use core::default::Default;
21 use core::iter::Peekable;
23 use core::mem::{replace, swap};
26 use {Collection, Mutable, Set, MutableSet, MutableMap, Map};
29 // This is implemented as an AA tree, which is a simplified variation of
30 // a red-black tree where red (horizontal) nodes can only be added
31 // as a right child. The time complexity is the same, and re-balancing
32 // operations are more frequent but also cheaper.
34 // Future improvements:
36 // range search - O(log n) retrieval of an iterator from some key
38 // (possibly) implement the overloads Python does for sets:
41 // * symmetric difference: ^
43 // These would be convenient since the methods work like `each`
47 pub struct TreeMap<K, V> {
48 root: Option<Box<TreeNode<K, V>>>,
52 impl<K: PartialEq + Ord, V: PartialEq> PartialEq for TreeMap<K, V> {
53 fn eq(&self, other: &TreeMap<K, V>) -> bool {
54 self.len() == other.len() &&
55 self.iter().zip(other.iter()).all(|(a, b)| a == b)
59 // Lexicographical comparison
60 fn lt<K: PartialOrd + Ord, V: PartialOrd>(a: &TreeMap<K, V>,
61 b: &TreeMap<K, V>) -> bool {
62 // the Zip iterator is as long as the shortest of a and b.
63 for ((key_a, value_a), (key_b, value_b)) in a.iter().zip(b.iter()) {
64 if *key_a < *key_b { return true; }
65 if *key_a > *key_b { return false; }
66 if *value_a < *value_b { return true; }
67 if *value_a > *value_b { return false; }
73 impl<K: PartialOrd + Ord, V: PartialOrd> PartialOrd for TreeMap<K, V> {
75 fn lt(&self, other: &TreeMap<K, V>) -> bool { lt(self, other) }
78 impl<K: Ord + Show, V: Show> Show for TreeMap<K, V> {
79 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
80 try!(write!(f, "{{"));
82 for (i, (k, v)) in self.iter().enumerate() {
83 if i != 0 { try!(write!(f, ", ")); }
84 try!(write!(f, "{}: {}", *k, *v));
91 impl<K: Ord, V> Collection for TreeMap<K, V> {
92 fn len(&self) -> uint { self.length }
95 impl<K: Ord, V> Mutable for TreeMap<K, V> {
102 impl<K: Ord, V> Map<K, V> for TreeMap<K, V> {
103 fn find<'a>(&'a self, key: &K) -> Option<&'a V> {
104 let mut current: &'a Option<Box<TreeNode<K, V>>> = &self.root;
108 match key.cmp(&r.key) {
109 Less => current = &r.left,
110 Greater => current = &r.right,
111 Equal => return Some(&r.value)
120 impl<K: Ord, V> MutableMap<K, V> for TreeMap<K, V> {
122 fn find_mut<'a>(&'a mut self, key: &K) -> Option<&'a mut V> {
123 find_mut(&mut self.root, key)
126 fn swap(&mut self, key: K, value: V) -> Option<V> {
127 let ret = insert(&mut self.root, key, value);
128 if ret.is_none() { self.length += 1 }
132 fn pop(&mut self, key: &K) -> Option<V> {
133 let ret = remove(&mut self.root, key);
134 if ret.is_some() { self.length -= 1 }
139 impl<K: Ord, V> Default for TreeMap<K,V> {
141 fn default() -> TreeMap<K, V> { TreeMap::new() }
144 impl<K: Ord, V> TreeMap<K, V> {
145 /// Create an empty TreeMap
146 pub fn new() -> TreeMap<K, V> { TreeMap{root: None, length: 0} }
148 /// Get a lazy iterator over the key-value pairs in the map.
149 /// Requires that it be frozen (immutable).
150 pub fn iter<'a>(&'a self) -> Entries<'a, K, V> {
153 node: deref(&self.root),
154 remaining_min: self.length,
155 remaining_max: self.length
159 /// Get a lazy reverse iterator over the key-value pairs in the map.
160 /// Requires that it be frozen (immutable).
161 pub fn rev_iter<'a>(&'a self) -> RevEntries<'a, K, V> {
162 RevEntries{iter: self.iter()}
165 /// Get a lazy forward iterator over the key-value pairs in the
166 /// map, with the values being mutable.
167 pub fn mut_iter<'a>(&'a mut self) -> MutEntries<'a, K, V> {
170 node: mut_deref(&mut self.root),
171 remaining_min: self.length,
172 remaining_max: self.length
175 /// Get a lazy reverse iterator over the key-value pairs in the
176 /// map, with the values being mutable.
177 pub fn mut_rev_iter<'a>(&'a mut self) -> RevMutEntries<'a, K, V> {
178 RevMutEntries{iter: self.mut_iter()}
182 /// Get a lazy iterator that consumes the treemap.
183 pub fn move_iter(self) -> MoveEntries<K, V> {
184 let TreeMap { root: root, length: length } = self;
185 let stk = match root {
187 Some(box tn) => vec!(tn)
198 macro_rules! bound_setup {
199 // initialiser of the iterator to manipulate
201 // whether we are looking for the lower or upper bound.
202 $is_lower_bound:expr) => {
204 let mut iter = $iter;
206 if !iter.node.is_null() {
207 let node_k = unsafe {&(*iter.node).key};
208 match k.cmp(node_k) {
209 Less => iter.traverse_left(),
210 Greater => iter.traverse_right(),
213 iter.traverse_complete();
216 iter.traverse_right()
221 iter.traverse_complete();
230 impl<K: Ord, V> TreeMap<K, V> {
231 /// Get a lazy iterator that should be initialized using
232 /// `traverse_left`/`traverse_right`/`traverse_complete`.
233 fn iter_for_traversal<'a>(&'a self) -> Entries<'a, K, V> {
236 node: deref(&self.root),
238 remaining_max: self.length
242 /// Return a lazy iterator to the first key-value pair whose key is not less than `k`
243 /// If all keys in map are less than `k` an empty iterator is returned.
244 pub fn lower_bound<'a>(&'a self, k: &K) -> Entries<'a, K, V> {
245 bound_setup!(self.iter_for_traversal(), true)
248 /// Return a lazy iterator to the first key-value pair whose key is greater than `k`
249 /// If all keys in map are not greater than `k` an empty iterator is returned.
250 pub fn upper_bound<'a>(&'a self, k: &K) -> Entries<'a, K, V> {
251 bound_setup!(self.iter_for_traversal(), false)
254 /// Get a lazy iterator that should be initialized using
255 /// `traverse_left`/`traverse_right`/`traverse_complete`.
256 fn mut_iter_for_traversal<'a>(&'a mut self) -> MutEntries<'a, K, V> {
259 node: mut_deref(&mut self.root),
261 remaining_max: self.length
265 /// Return a lazy value iterator to the first key-value pair (with
266 /// the value being mutable) whose key is not less than `k`.
268 /// If all keys in map are less than `k` an empty iterator is
270 pub fn mut_lower_bound<'a>(&'a mut self, k: &K) -> MutEntries<'a, K, V> {
271 bound_setup!(self.mut_iter_for_traversal(), true)
274 /// Return a lazy iterator to the first key-value pair (with the
275 /// value being mutable) whose key is greater than `k`.
277 /// If all keys in map are not greater than `k` an empty iterator
279 pub fn mut_upper_bound<'a>(&'a mut self, k: &K) -> MutEntries<'a, K, V> {
280 bound_setup!(self.mut_iter_for_traversal(), false)
284 /// Lazy forward iterator over a map
285 pub struct Entries<'a, K, V> {
286 stack: Vec<&'a TreeNode<K, V>>,
287 // See the comment on MutEntries; this is just to allow
288 // code-sharing (for this immutable-values iterator it *could* very
289 // well be Option<&'a TreeNode<K,V>>).
290 node: *TreeNode<K, V>,
295 /// Lazy backward iterator over a map
296 pub struct RevEntries<'a, K, V> {
297 iter: Entries<'a, K, V>,
300 /// Lazy forward iterator over a map that allows for the mutation of
302 pub struct MutEntries<'a, K, V> {
303 stack: Vec<&'a mut TreeNode<K, V>>,
304 // Unfortunately, we require some unsafe-ness to get around the
305 // fact that we would be storing a reference *into* one of the
306 // nodes in the stack.
308 // As far as the compiler knows, this would let us invalidate the
309 // reference by assigning a new value to this node's position in
310 // its parent, which would cause this current one to be
311 // deallocated so this reference would be invalid. (i.e. the
312 // compilers complaints are 100% correct.)
314 // However, as far as you humans reading this code know (or are
315 // about to know, if you haven't read far enough down yet), we are
316 // only reading from the TreeNode.{left,right} fields. the only
317 // thing that is ever mutated is the .value field (although any
318 // actual mutation that happens is done externally, by the
319 // iterator consumer). So, don't be so concerned, rustc, we've got
322 // (This field can legitimately be null.)
323 node: *mut TreeNode<K, V>,
328 /// Lazy backward iterator over a map
329 pub struct RevMutEntries<'a, K, V> {
330 iter: MutEntries<'a, K, V>,
334 // FIXME #5846 we want to be able to choose between &x and &mut x
335 // (with many different `x`) below, so we need to optionally pass mut
336 // as a tt, but the only thing we can do with a `tt` is pass them to
337 // other macros, so this takes the `& <mutability> <operand>` token
338 // sequence and forces their evaluation as an expression.
339 macro_rules! addr { ($e:expr) => { $e }}
340 // putting an optional mut into type signatures
341 macro_rules! item { ($i:item) => { $i }}
343 macro_rules! define_iterator {
347 // the function to go from &m Option<Box<TreeNode>> to *m TreeNode
348 deref = $deref:ident,
350 // see comment on `addr!`, this is just an optional `mut`, but
351 // there's no support for 0-or-1 repeats.
352 addr_mut = $($addr_mut:tt)*
354 // private methods on the forward iterator (item!() for the
355 // addr_mut in the next_ return value)
356 item!(impl<'a, K, V> $name<'a, K, V> {
358 fn next_(&mut self, forward: bool) -> Option<(&'a K, &'a $($addr_mut)* V)> {
359 while !self.stack.is_empty() || !self.node.is_null() {
360 if !self.node.is_null() {
361 let node = unsafe {addr!(& $($addr_mut)* *self.node)};
363 let next_node = if forward {
364 addr!(& $($addr_mut)* node.left)
366 addr!(& $($addr_mut)* node.right)
368 self.node = $deref(next_node);
370 self.stack.push(node);
372 let node = self.stack.pop().unwrap();
373 let next_node = if forward {
374 addr!(& $($addr_mut)* node.right)
376 addr!(& $($addr_mut)* node.left)
378 self.node = $deref(next_node);
379 self.remaining_max -= 1;
380 if self.remaining_min > 0 {
381 self.remaining_min -= 1;
383 return Some((&node.key, addr!(& $($addr_mut)* node.value)));
389 /// traverse_left, traverse_right and traverse_complete are
390 /// used to initialize Entries/MutEntries
391 /// pointing to element inside tree structure.
393 /// They should be used in following manner:
394 /// - create iterator using TreeMap::[mut_]iter_for_traversal
395 /// - find required node using `traverse_left`/`traverse_right`
396 /// (current node is `Entries::node` field)
397 /// - complete initialization with `traverse_complete`
399 /// After this, iteration will start from `self.node`. If
400 /// `self.node` is None iteration will start from last
401 /// node from which we traversed left.
403 fn traverse_left(&mut self) {
404 let node = unsafe {addr!(& $($addr_mut)* *self.node)};
405 self.node = $deref(addr!(& $($addr_mut)* node.left));
406 self.stack.push(node);
410 fn traverse_right(&mut self) {
411 let node = unsafe {addr!(& $($addr_mut)* *self.node)};
412 self.node = $deref(addr!(& $($addr_mut)* node.right));
416 fn traverse_complete(&mut self) {
417 if !self.node.is_null() {
419 self.stack.push(addr!(& $($addr_mut)* *self.node));
421 self.node = ptr::RawPtr::null();
426 // the forward Iterator impl.
427 item!(impl<'a, K, V> Iterator<(&'a K, &'a $($addr_mut)* V)> for $name<'a, K, V> {
428 /// Advance the iterator to the next node (in order) and return a
429 /// tuple with a reference to the key and value. If there are no
430 /// more nodes, return `None`.
431 fn next(&mut self) -> Option<(&'a K, &'a $($addr_mut)* V)> {
436 fn size_hint(&self) -> (uint, Option<uint>) {
437 (self.remaining_min, Some(self.remaining_max))
441 // the reverse Iterator impl.
442 item!(impl<'a, K, V> Iterator<(&'a K, &'a $($addr_mut)* V)> for $rev_name<'a, K, V> {
443 fn next(&mut self) -> Option<(&'a K, &'a $($addr_mut)* V)> {
444 self.iter.next_(false)
448 fn size_hint(&self) -> (uint, Option<uint>) {
449 self.iter.size_hint()
453 } // end of define_iterator
460 // immutable, so no mut
471 fn deref<'a, K, V>(node: &'a Option<Box<TreeNode<K, V>>>) -> *TreeNode<K, V> {
474 let n: &TreeNode<K, V> = *n;
481 fn mut_deref<K, V>(x: &mut Option<Box<TreeNode<K, V>>>)
482 -> *mut TreeNode<K, V> {
485 let n: &mut TreeNode<K, V> = *n;
486 n as *mut TreeNode<K, V>
488 None => ptr::mut_null()
494 /// Lazy forward iterator over a map that consumes the map while iterating
495 pub struct MoveEntries<K, V> {
496 stack: Vec<TreeNode<K, V>>,
500 impl<K, V> Iterator<(K, V)> for MoveEntries<K,V> {
502 fn next(&mut self) -> Option<(K, V)> {
503 while !self.stack.is_empty() {
510 } = self.stack.pop().unwrap();
522 self.stack.push(left);
526 Some(box right) => self.stack.push(right),
530 return Some((key, value))
538 fn size_hint(&self) -> (uint, Option<uint>) {
539 (self.remaining, Some(self.remaining))
544 impl<'a, T> Iterator<&'a T> for SetItems<'a, T> {
546 fn next(&mut self) -> Option<&'a T> {
547 self.iter.next().map(|(value, _)| value)
551 impl<'a, T> Iterator<&'a T> for RevSetItems<'a, T> {
553 fn next(&mut self) -> Option<&'a T> {
554 self.iter.next().map(|(value, _)| value)
558 /// A implementation of the `Set` trait on top of the `TreeMap` container. The
559 /// only requirement is that the type of the elements contained ascribes to the
562 pub struct TreeSet<T> {
566 impl<T: PartialEq + Ord> PartialEq for TreeSet<T> {
568 fn eq(&self, other: &TreeSet<T>) -> bool { self.map == other.map }
571 impl<T: PartialOrd + Ord> PartialOrd for TreeSet<T> {
573 fn lt(&self, other: &TreeSet<T>) -> bool { self.map < other.map }
576 impl<T: Ord + Show> Show for TreeSet<T> {
577 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
578 try!(write!(f, "{{"));
580 for (i, x) in self.iter().enumerate() {
581 if i != 0 { try!(write!(f, ", ")); }
582 try!(write!(f, "{}", *x));
589 impl<T: Ord> Collection for TreeSet<T> {
591 fn len(&self) -> uint { self.map.len() }
594 impl<T: Ord> Mutable for TreeSet<T> {
596 fn clear(&mut self) { self.map.clear() }
599 impl<T: Ord> Set<T> for TreeSet<T> {
601 fn contains(&self, value: &T) -> bool {
602 self.map.contains_key(value)
605 fn is_disjoint(&self, other: &TreeSet<T>) -> bool {
606 self.intersection(other).next().is_none()
609 fn is_subset(&self, other: &TreeSet<T>) -> bool {
610 let mut x = self.iter();
611 let mut y = other.iter();
612 let mut a = x.next();
613 let mut b = y.next();
624 Greater => return false,
625 Equal => a = x.next(),
634 impl<T: Ord> MutableSet<T> for TreeSet<T> {
636 fn insert(&mut self, value: T) -> bool { self.map.insert(value, ()) }
639 fn remove(&mut self, value: &T) -> bool { self.map.remove(value) }
642 impl<T: Ord> Default for TreeSet<T> {
644 fn default() -> TreeSet<T> { TreeSet::new() }
647 impl<T: Ord> TreeSet<T> {
648 /// Create an empty TreeSet
650 pub fn new() -> TreeSet<T> { TreeSet{map: TreeMap::new()} }
652 /// Get a lazy iterator over the values in the set.
653 /// Requires that it be frozen (immutable).
655 pub fn iter<'a>(&'a self) -> SetItems<'a, T> {
656 SetItems{iter: self.map.iter()}
659 /// Get a lazy iterator over the values in the set.
660 /// Requires that it be frozen (immutable).
662 pub fn rev_iter<'a>(&'a self) -> RevSetItems<'a, T> {
663 RevSetItems{iter: self.map.rev_iter()}
666 /// Get a lazy iterator that consumes the set.
668 pub fn move_iter(self) -> MoveSetItems<T> {
669 self.map.move_iter().map(|(value, _)| value)
672 /// Get a lazy iterator pointing to the first value not less than `v` (greater or equal).
673 /// If all elements in the set are less than `v` empty iterator is returned.
675 pub fn lower_bound<'a>(&'a self, v: &T) -> SetItems<'a, T> {
676 SetItems{iter: self.map.lower_bound(v)}
679 /// Get a lazy iterator pointing to the first value greater than `v`.
680 /// If all elements in the set are not greater than `v` empty iterator is returned.
682 pub fn upper_bound<'a>(&'a self, v: &T) -> SetItems<'a, T> {
683 SetItems{iter: self.map.upper_bound(v)}
686 /// Visit the values (in-order) representing the difference
687 pub fn difference<'a>(&'a self, other: &'a TreeSet<T>) -> DifferenceItems<'a, T> {
688 DifferenceItems{a: self.iter().peekable(), b: other.iter().peekable()}
691 /// Visit the values (in-order) representing the symmetric difference
692 pub fn symmetric_difference<'a>(&'a self, other: &'a TreeSet<T>)
693 -> SymDifferenceItems<'a, T> {
694 SymDifferenceItems{a: self.iter().peekable(), b: other.iter().peekable()}
697 /// Visit the values (in-order) representing the intersection
698 pub fn intersection<'a>(&'a self, other: &'a TreeSet<T>)
699 -> IntersectionItems<'a, T> {
700 IntersectionItems{a: self.iter().peekable(), b: other.iter().peekable()}
703 /// Visit the values (in-order) representing the union
704 pub fn union<'a>(&'a self, other: &'a TreeSet<T>) -> UnionItems<'a, T> {
705 UnionItems{a: self.iter().peekable(), b: other.iter().peekable()}
709 /// Lazy forward iterator over a set
710 pub struct SetItems<'a, T> {
711 iter: Entries<'a, T, ()>
714 /// Lazy backward iterator over a set
715 pub struct RevSetItems<'a, T> {
716 iter: RevEntries<'a, T, ()>
719 /// Lazy forward iterator over a set that consumes the set while iterating
720 pub type MoveSetItems<T> = iter::Map<'static, (T, ()), T, MoveEntries<T, ()>>;
722 /// Lazy iterator producing elements in the set difference (in-order)
723 pub struct DifferenceItems<'a, T> {
724 a: Peekable<&'a T, SetItems<'a, T>>,
725 b: Peekable<&'a T, SetItems<'a, T>>,
728 /// Lazy iterator producing elements in the set symmetric difference (in-order)
729 pub struct SymDifferenceItems<'a, T> {
730 a: Peekable<&'a T, SetItems<'a, T>>,
731 b: Peekable<&'a T, SetItems<'a, T>>,
734 /// Lazy iterator producing elements in the set intersection (in-order)
735 pub struct IntersectionItems<'a, T> {
736 a: Peekable<&'a T, SetItems<'a, T>>,
737 b: Peekable<&'a T, SetItems<'a, T>>,
740 /// Lazy iterator producing elements in the set union (in-order)
741 pub struct UnionItems<'a, T> {
742 a: Peekable<&'a T, SetItems<'a, T>>,
743 b: Peekable<&'a T, SetItems<'a, T>>,
746 /// Compare `x` and `y`, but return `short` if x is None and `long` if y is None
747 fn cmp_opt<T: Ord>(x: Option<&T>, y: Option<&T>,
748 short: Ordering, long: Ordering) -> Ordering {
750 (None , _ ) => short,
752 (Some(x1), Some(y1)) => x1.cmp(y1),
756 impl<'a, T: Ord> Iterator<&'a T> for DifferenceItems<'a, T> {
757 fn next(&mut self) -> Option<&'a T> {
759 match cmp_opt(self.a.peek(), self.b.peek(), Less, Less) {
760 Less => return self.a.next(),
761 Equal => { self.a.next(); self.b.next(); }
762 Greater => { self.b.next(); }
768 impl<'a, T: Ord> Iterator<&'a T> for SymDifferenceItems<'a, T> {
769 fn next(&mut self) -> Option<&'a T> {
771 match cmp_opt(self.a.peek(), self.b.peek(), Greater, Less) {
772 Less => return self.a.next(),
773 Equal => { self.a.next(); self.b.next(); }
774 Greater => return self.b.next(),
780 impl<'a, T: Ord> Iterator<&'a T> for IntersectionItems<'a, T> {
781 fn next(&mut self) -> Option<&'a T> {
783 let o_cmp = match (self.a.peek(), self.b.peek()) {
786 (Some(a1), Some(b1)) => Some(a1.cmp(b1)),
790 Some(Less) => { self.a.next(); }
791 Some(Equal) => { self.b.next(); return self.a.next() }
792 Some(Greater) => { self.b.next(); }
798 impl<'a, T: Ord> Iterator<&'a T> for UnionItems<'a, T> {
799 fn next(&mut self) -> Option<&'a T> {
801 match cmp_opt(self.a.peek(), self.b.peek(), Greater, Less) {
802 Less => return self.a.next(),
803 Equal => { self.b.next(); return self.a.next() }
804 Greater => return self.b.next(),
811 // Nodes keep track of their level in the tree, starting at 1 in the
812 // leaves and with a red child sharing the level of the parent.
814 struct TreeNode<K, V> {
817 left: Option<Box<TreeNode<K, V>>>,
818 right: Option<Box<TreeNode<K, V>>>,
822 impl<K: Ord, V> TreeNode<K, V> {
823 /// Creates a new tree node.
825 pub fn new(key: K, value: V) -> TreeNode<K, V> {
826 TreeNode{key: key, value: value, left: None, right: None, level: 1}
830 // Remove left horizontal link by rotating right
831 fn skew<K: Ord, V>(node: &mut Box<TreeNode<K, V>>) {
832 if node.left.as_ref().map_or(false, |x| x.level == node.level) {
833 let mut save = node.left.take_unwrap();
834 swap(&mut node.left, &mut save.right); // save.right now None
835 swap(node, &mut save);
836 node.right = Some(save);
840 // Remove dual horizontal link by rotating left and increasing level of
842 fn split<K: Ord, V>(node: &mut Box<TreeNode<K, V>>) {
843 if node.right.as_ref().map_or(false,
844 |x| x.right.as_ref().map_or(false, |y| y.level == node.level)) {
845 let mut save = node.right.take_unwrap();
846 swap(&mut node.right, &mut save.left); // save.left now None
848 swap(node, &mut save);
849 node.left = Some(save);
853 fn find_mut<'r, K: Ord, V>(node: &'r mut Option<Box<TreeNode<K, V>>>,
855 -> Option<&'r mut V> {
858 match key.cmp(&x.key) {
859 Less => find_mut(&mut x.left, key),
860 Greater => find_mut(&mut x.right, key),
861 Equal => Some(&mut x.value),
868 fn insert<K: Ord, V>(node: &mut Option<Box<TreeNode<K, V>>>,
869 key: K, value: V) -> Option<V> {
871 Some(ref mut save) => {
872 match key.cmp(&save.key) {
874 let inserted = insert(&mut save.left, key, value);
880 let inserted = insert(&mut save.right, key, value);
887 Some(replace(&mut save.value, value))
892 *node = Some(box TreeNode::new(key, value));
898 fn remove<K: Ord, V>(node: &mut Option<Box<TreeNode<K, V>>>,
899 key: &K) -> Option<V> {
900 fn heir_swap<K: Ord, V>(node: &mut Box<TreeNode<K, V>>,
901 child: &mut Option<Box<TreeNode<K, V>>>) {
902 // *could* be done without recursion, but it won't borrow check
903 for x in child.mut_iter() {
904 if x.right.is_some() {
905 heir_swap(node, &mut x.right);
907 swap(&mut node.key, &mut x.key);
908 swap(&mut node.value, &mut x.value);
915 return None; // bottom of tree
917 Some(ref mut save) => {
918 let (ret, rebalance) = match key.cmp(&save.key) {
919 Less => (remove(&mut save.left, key), true),
920 Greater => (remove(&mut save.right, key), true),
922 if save.left.is_some() {
923 if save.right.is_some() {
924 let mut left = save.left.take_unwrap();
925 if left.right.is_some() {
926 heir_swap(save, &mut left.right);
928 swap(&mut save.key, &mut left.key);
929 swap(&mut save.value, &mut left.value);
931 save.left = Some(left);
932 (remove(&mut save.left, key), true)
934 let new = save.left.take_unwrap();
935 let box TreeNode{value, ..} = replace(save, new);
936 *save = save.left.take_unwrap();
939 } else if save.right.is_some() {
940 let new = save.right.take_unwrap();
941 let box TreeNode{value, ..} = replace(save, new);
950 let left_level = save.left.as_ref().map_or(0, |x| x.level);
951 let right_level = save.right.as_ref().map_or(0, |x| x.level);
953 // re-balance, if necessary
954 if left_level < save.level - 1 || right_level < save.level - 1 {
957 if right_level > save.level {
958 for x in save.right.mut_iter() { x.level = save.level }
963 for right in save.right.mut_iter() {
965 for x in right.right.mut_iter() { skew(x) }
969 for x in save.right.mut_iter() { split(x) }
976 return match node.take() {
977 Some(box TreeNode{value, ..}) => Some(value), None => fail!()
981 impl<K: Ord, V> FromIterator<(K, V)> for TreeMap<K, V> {
982 fn from_iter<T: Iterator<(K, V)>>(iter: T) -> TreeMap<K, V> {
983 let mut map = TreeMap::new();
989 impl<K: Ord, V> Extendable<(K, V)> for TreeMap<K, V> {
991 fn extend<T: Iterator<(K, V)>>(&mut self, mut iter: T) {
998 impl<T: Ord> FromIterator<T> for TreeSet<T> {
999 fn from_iter<Iter: Iterator<T>>(iter: Iter) -> TreeSet<T> {
1000 let mut set = TreeSet::new();
1006 impl<T: Ord> Extendable<T> for TreeSet<T> {
1008 fn extend<Iter: Iterator<T>>(&mut self, mut iter: Iter) {
1017 use std::prelude::*;
1021 use {Map, MutableMap, Mutable};
1022 use super::{TreeMap, TreeNode};
1026 let m: TreeMap<int,int> = TreeMap::new();
1027 assert!(m.find(&5) == None);
1031 fn find_not_found() {
1032 let mut m = TreeMap::new();
1033 assert!(m.insert(1, 2));
1034 assert!(m.insert(5, 3));
1035 assert!(m.insert(9, 3));
1036 assert_eq!(m.find(&2), None);
1040 fn test_find_mut() {
1041 let mut m = TreeMap::new();
1042 assert!(m.insert(1, 12));
1043 assert!(m.insert(2, 8));
1044 assert!(m.insert(5, 14));
1046 match m.find_mut(&5) {
1047 None => fail!(), Some(x) => *x = new
1049 assert_eq!(m.find(&5), Some(&new));
1053 fn insert_replace() {
1054 let mut m = TreeMap::new();
1055 assert!(m.insert(5, 2));
1056 assert!(m.insert(2, 9));
1057 assert!(!m.insert(2, 11));
1058 assert_eq!(m.find(&2).unwrap(), &11);
1063 let mut m = TreeMap::new();
1065 assert!(m.insert(5, 11));
1066 assert!(m.insert(12, -3));
1067 assert!(m.insert(19, 2));
1069 assert!(m.find(&5).is_none());
1070 assert!(m.find(&12).is_none());
1071 assert!(m.find(&19).is_none());
1072 assert!(m.is_empty());
1077 let mut m = TreeMap::new();
1079 let k1 = "foo".as_bytes();
1080 let k2 = "bar".as_bytes();
1081 let v1 = "baz".as_bytes();
1082 let v2 = "foobar".as_bytes();
1084 m.insert(k1.clone(), v1.clone());
1085 m.insert(k2.clone(), v2.clone());
1087 assert_eq!(m.find(&k2), Some(&v2));
1088 assert_eq!(m.find(&k1), Some(&v1));
1091 fn check_equal<K: PartialEq + Ord, V: PartialEq>(ctrl: &[(K, V)],
1092 map: &TreeMap<K, V>) {
1093 assert_eq!(ctrl.is_empty(), map.is_empty());
1094 for x in ctrl.iter() {
1095 let &(ref k, ref v) = x;
1096 assert!(map.find(k).unwrap() == v)
1098 for (map_k, map_v) in map.iter() {
1099 let mut found = false;
1100 for x in ctrl.iter() {
1101 let &(ref ctrl_k, ref ctrl_v) = x;
1102 if *map_k == *ctrl_k {
1103 assert!(*map_v == *ctrl_v);
1112 fn check_left<K: Ord, V>(node: &Option<Box<TreeNode<K, V>>>,
1113 parent: &Box<TreeNode<K, V>>) {
1116 assert_eq!(r.key.cmp(&parent.key), Less);
1117 assert!(r.level == parent.level - 1); // left is black
1118 check_left(&r.left, r);
1119 check_right(&r.right, r, false);
1121 None => assert!(parent.level == 1) // parent is leaf
1125 fn check_right<K: Ord, V>(node: &Option<Box<TreeNode<K, V>>>,
1126 parent: &Box<TreeNode<K, V>>,
1130 assert_eq!(r.key.cmp(&parent.key), Greater);
1131 let red = r.level == parent.level;
1132 if parent_red { assert!(!red) } // no dual horizontal links
1133 // Right red or black
1134 assert!(red || r.level == parent.level - 1);
1135 check_left(&r.left, r);
1136 check_right(&r.right, r, red);
1138 None => assert!(parent.level == 1) // parent is leaf
1142 fn check_structure<K: Ord, V>(map: &TreeMap<K, V>) {
1145 check_left(&r.left, r);
1146 check_right(&r.right, r, false);
1153 fn test_rand_int() {
1154 let mut map: TreeMap<int,int> = TreeMap::new();
1155 let mut ctrl = vec![];
1157 check_equal(ctrl.as_slice(), &map);
1158 assert!(map.find(&5).is_none());
1160 let mut rng: rand::IsaacRng = rand::SeedableRng::from_seed(&[42]);
1162 for _ in range(0, 3) {
1163 for _ in range(0, 90) {
1166 if !ctrl.iter().any(|x| x == &(k, v)) {
1167 assert!(map.insert(k, v));
1169 check_structure(&map);
1170 check_equal(ctrl.as_slice(), &map);
1174 for _ in range(0, 30) {
1175 let r = rng.gen_range(0, ctrl.len());
1176 let (key, _) = ctrl.remove(r).unwrap();
1177 assert!(map.remove(&key));
1178 check_structure(&map);
1179 check_equal(ctrl.as_slice(), &map);
1186 let mut m = TreeMap::new();
1187 assert!(m.insert(3, 6));
1188 assert_eq!(m.len(), 1);
1189 assert!(m.insert(0, 0));
1190 assert_eq!(m.len(), 2);
1191 assert!(m.insert(4, 8));
1192 assert_eq!(m.len(), 3);
1193 assert!(m.remove(&3));
1194 assert_eq!(m.len(), 2);
1195 assert!(!m.remove(&5));
1196 assert_eq!(m.len(), 2);
1197 assert!(m.insert(2, 4));
1198 assert_eq!(m.len(), 3);
1199 assert!(m.insert(1, 2));
1200 assert_eq!(m.len(), 4);
1204 fn test_iterator() {
1205 let mut m = TreeMap::new();
1207 assert!(m.insert(3, 6));
1208 assert!(m.insert(0, 0));
1209 assert!(m.insert(4, 8));
1210 assert!(m.insert(2, 4));
1211 assert!(m.insert(1, 2));
1214 for (k, v) in m.iter() {
1216 assert_eq!(*v, n * 2);
1223 fn test_interval_iteration() {
1224 let mut m = TreeMap::new();
1225 for i in range(1, 100) {
1226 assert!(m.insert(i * 2, i * 4));
1229 for i in range(1, 198) {
1230 let mut lb_it = m.lower_bound(&i);
1231 let (&k, &v) = lb_it.next().unwrap();
1234 assert_eq!(lb * 2, v);
1236 let mut ub_it = m.upper_bound(&i);
1237 let (&k, &v) = ub_it.next().unwrap();
1238 let ub = i + 2 - i % 2;
1240 assert_eq!(ub * 2, v);
1242 let mut end_it = m.lower_bound(&199);
1243 assert_eq!(end_it.next(), None);
1247 fn test_rev_iter() {
1248 let mut m = TreeMap::new();
1250 assert!(m.insert(3, 6));
1251 assert!(m.insert(0, 0));
1252 assert!(m.insert(4, 8));
1253 assert!(m.insert(2, 4));
1254 assert!(m.insert(1, 2));
1257 for (k, v) in m.rev_iter() {
1259 assert_eq!(*v, n * 2);
1265 fn test_mut_iter() {
1266 let mut m = TreeMap::new();
1267 for i in range(0u, 10) {
1268 assert!(m.insert(i, 100 * i));
1271 for (i, (&k, v)) in m.mut_iter().enumerate() {
1272 *v += k * 10 + i; // 000 + 00 + 0, 100 + 10 + 1, ...
1275 for (&k, &v) in m.iter() {
1276 assert_eq!(v, 111 * k);
1280 fn test_mut_rev_iter() {
1281 let mut m = TreeMap::new();
1282 for i in range(0u, 10) {
1283 assert!(m.insert(i, 100 * i));
1286 for (i, (&k, v)) in m.mut_rev_iter().enumerate() {
1287 *v += k * 10 + (9 - i); // 900 + 90 + (9 - 0), 800 + 80 + (9 - 1), ...
1290 for (&k, &v) in m.iter() {
1291 assert_eq!(v, 111 * k);
1296 fn test_mut_interval_iter() {
1297 let mut m_lower = TreeMap::new();
1298 let mut m_upper = TreeMap::new();
1299 for i in range(1, 100) {
1300 assert!(m_lower.insert(i * 2, i * 4));
1301 assert!(m_upper.insert(i * 2, i * 4));
1304 for i in range(1, 199) {
1305 let mut lb_it = m_lower.mut_lower_bound(&i);
1306 let (&k, v) = lb_it.next().unwrap();
1311 for i in range(0, 198) {
1312 let mut ub_it = m_upper.mut_upper_bound(&i);
1313 let (&k, v) = ub_it.next().unwrap();
1314 let ub = i + 2 - i % 2;
1319 assert!(m_lower.mut_lower_bound(&199).next().is_none());
1321 assert!(m_upper.mut_upper_bound(&198).next().is_none());
1323 assert!(m_lower.iter().all(|(_, &x)| x == 0));
1324 assert!(m_upper.iter().all(|(_, &x)| x == 0));
1329 let mut a = TreeMap::new();
1330 let mut b = TreeMap::new();
1333 assert!(a.insert(0, 5));
1335 assert!(b.insert(0, 4));
1337 assert!(a.insert(5, 19));
1339 assert!(!b.insert(0, 5));
1341 assert!(b.insert(5, 19));
1347 let mut a = TreeMap::new();
1348 let mut b = TreeMap::new();
1350 assert!(!(a < b) && !(b < a));
1351 assert!(b.insert(0, 5));
1353 assert!(a.insert(0, 7));
1354 assert!(!(a < b) && b < a);
1355 assert!(b.insert(-2, 0));
1357 assert!(a.insert(-5, 2));
1359 assert!(a.insert(6, 2));
1360 assert!(a < b && !(b < a));
1365 let mut a = TreeMap::new();
1366 let mut b = TreeMap::new();
1368 assert!(a <= b && a >= b);
1369 assert!(a.insert(1, 1));
1370 assert!(a > b && a >= b);
1371 assert!(b < a && b <= a);
1372 assert!(b.insert(2, 2));
1373 assert!(b > a && b >= a);
1374 assert!(a < b && a <= b);
1379 let mut map: TreeMap<int, int> = TreeMap::new();
1380 let empty: TreeMap<int, int> = TreeMap::new();
1385 let map_str = format!("{}", map);
1387 assert!(map_str == "{1: 2, 3: 4}".to_string());
1388 assert_eq!(format!("{}", empty), "{}".to_string());
1392 fn test_lazy_iterator() {
1393 let mut m = TreeMap::new();
1394 let (x1, y1) = (2, 5);
1395 let (x2, y2) = (9, 12);
1396 let (x3, y3) = (20, -3);
1397 let (x4, y4) = (29, 5);
1398 let (x5, y5) = (103, 3);
1400 assert!(m.insert(x1, y1));
1401 assert!(m.insert(x2, y2));
1402 assert!(m.insert(x3, y3));
1403 assert!(m.insert(x4, y4));
1404 assert!(m.insert(x5, y5));
1407 let mut a = m.iter();
1409 assert_eq!(a.next().unwrap(), (&x1, &y1));
1410 assert_eq!(a.next().unwrap(), (&x2, &y2));
1411 assert_eq!(a.next().unwrap(), (&x3, &y3));
1412 assert_eq!(a.next().unwrap(), (&x4, &y4));
1413 assert_eq!(a.next().unwrap(), (&x5, &y5));
1415 assert!(a.next().is_none());
1417 let mut b = m.iter();
1419 let expected = [(&x1, &y1), (&x2, &y2), (&x3, &y3), (&x4, &y4),
1424 assert_eq!(expected[i], x);
1433 assert_eq!(expected[i], x);
1439 fn test_from_iter() {
1440 let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
1442 let map: TreeMap<int, int> = xs.iter().map(|&x| x).collect();
1444 for &(k, v) in xs.iter() {
1445 assert_eq!(map.find(&k), Some(&v));
1456 use deque::bench::{insert_rand_n, insert_seq_n, find_rand_n, find_seq_n};
1460 pub fn insert_rand_100(b: &mut Bencher) {
1461 let mut m : TreeMap<uint,uint> = TreeMap::new();
1462 insert_rand_n(100, &mut m, b);
1466 pub fn insert_rand_10_000(b: &mut Bencher) {
1467 let mut m : TreeMap<uint,uint> = TreeMap::new();
1468 insert_rand_n(10_000, &mut m, b);
1473 pub fn insert_seq_100(b: &mut Bencher) {
1474 let mut m : TreeMap<uint,uint> = TreeMap::new();
1475 insert_seq_n(100, &mut m, b);
1479 pub fn insert_seq_10_000(b: &mut Bencher) {
1480 let mut m : TreeMap<uint,uint> = TreeMap::new();
1481 insert_seq_n(10_000, &mut m, b);
1486 pub fn find_rand_100(b: &mut Bencher) {
1487 let mut m : TreeMap<uint,uint> = TreeMap::new();
1488 find_rand_n(100, &mut m, b);
1492 pub fn find_rand_10_000(b: &mut Bencher) {
1493 let mut m : TreeMap<uint,uint> = TreeMap::new();
1494 find_rand_n(10_000, &mut m, b);
1499 pub fn find_seq_100(b: &mut Bencher) {
1500 let mut m : TreeMap<uint,uint> = TreeMap::new();
1501 find_seq_n(100, &mut m, b);
1505 pub fn find_seq_10_000(b: &mut Bencher) {
1506 let mut m : TreeMap<uint,uint> = TreeMap::new();
1507 find_seq_n(10_000, &mut m, b);
1513 use std::prelude::*;
1515 use {Set, MutableSet, Mutable, MutableMap};
1516 use super::{TreeMap, TreeSet};
1520 let mut s = TreeSet::new();
1522 assert!(s.insert(5));
1523 assert!(s.insert(12));
1524 assert!(s.insert(19));
1526 assert!(!s.contains(&5));
1527 assert!(!s.contains(&12));
1528 assert!(!s.contains(&19));
1529 assert!(s.is_empty());
1533 fn test_disjoint() {
1534 let mut xs = TreeSet::new();
1535 let mut ys = TreeSet::new();
1536 assert!(xs.is_disjoint(&ys));
1537 assert!(ys.is_disjoint(&xs));
1538 assert!(xs.insert(5));
1539 assert!(ys.insert(11));
1540 assert!(xs.is_disjoint(&ys));
1541 assert!(ys.is_disjoint(&xs));
1542 assert!(xs.insert(7));
1543 assert!(xs.insert(19));
1544 assert!(xs.insert(4));
1545 assert!(ys.insert(2));
1546 assert!(ys.insert(-11));
1547 assert!(xs.is_disjoint(&ys));
1548 assert!(ys.is_disjoint(&xs));
1549 assert!(ys.insert(7));
1550 assert!(!xs.is_disjoint(&ys));
1551 assert!(!ys.is_disjoint(&xs));
1555 fn test_subset_and_superset() {
1556 let mut a = TreeSet::new();
1557 assert!(a.insert(0));
1558 assert!(a.insert(5));
1559 assert!(a.insert(11));
1560 assert!(a.insert(7));
1562 let mut b = TreeSet::new();
1563 assert!(b.insert(0));
1564 assert!(b.insert(7));
1565 assert!(b.insert(19));
1566 assert!(b.insert(250));
1567 assert!(b.insert(11));
1568 assert!(b.insert(200));
1570 assert!(!a.is_subset(&b));
1571 assert!(!a.is_superset(&b));
1572 assert!(!b.is_subset(&a));
1573 assert!(!b.is_superset(&a));
1575 assert!(b.insert(5));
1577 assert!(a.is_subset(&b));
1578 assert!(!a.is_superset(&b));
1579 assert!(!b.is_subset(&a));
1580 assert!(b.is_superset(&a));
1584 fn test_iterator() {
1585 let mut m = TreeSet::new();
1587 assert!(m.insert(3));
1588 assert!(m.insert(0));
1589 assert!(m.insert(4));
1590 assert!(m.insert(2));
1591 assert!(m.insert(1));
1601 fn test_rev_iter() {
1602 let mut m = TreeSet::new();
1604 assert!(m.insert(3));
1605 assert!(m.insert(0));
1606 assert!(m.insert(4));
1607 assert!(m.insert(2));
1608 assert!(m.insert(1));
1611 for x in m.rev_iter() {
1618 fn test_move_iter() {
1619 let s: TreeSet<int> = range(0, 5).collect();
1622 for x in s.move_iter() {
1629 fn test_move_iter_size_hint() {
1630 let s: TreeSet<int> = vec!(0, 1).move_iter().collect();
1632 let mut it = s.move_iter();
1634 assert_eq!(it.size_hint(), (2, Some(2)));
1635 assert!(it.next() != None);
1637 assert_eq!(it.size_hint(), (1, Some(1)));
1638 assert!(it.next() != None);
1640 assert_eq!(it.size_hint(), (0, Some(0)));
1641 assert_eq!(it.next(), None);
1645 fn test_clone_eq() {
1646 let mut m = TreeSet::new();
1651 assert!(m.clone() == m);
1657 f: |&TreeSet<int>, &TreeSet<int>, f: |&int| -> bool| -> bool) {
1658 let mut set_a = TreeSet::new();
1659 let mut set_b = TreeSet::new();
1661 for x in a.iter() { assert!(set_a.insert(*x)) }
1662 for y in b.iter() { assert!(set_b.insert(*y)) }
1665 f(&set_a, &set_b, |x| {
1666 assert_eq!(*x, expected[i]);
1670 assert_eq!(i, expected.len());
1674 fn test_intersection() {
1675 fn check_intersection(a: &[int], b: &[int], expected: &[int]) {
1676 check(a, b, expected, |x, y, f| x.intersection(y).advance(f))
1679 check_intersection([], [], []);
1680 check_intersection([1, 2, 3], [], []);
1681 check_intersection([], [1, 2, 3], []);
1682 check_intersection([2], [1, 2, 3], [2]);
1683 check_intersection([1, 2, 3], [2], [2]);
1684 check_intersection([11, 1, 3, 77, 103, 5, -5],
1685 [2, 11, 77, -9, -42, 5, 3],
1690 fn test_difference() {
1691 fn check_difference(a: &[int], b: &[int], expected: &[int]) {
1692 check(a, b, expected, |x, y, f| x.difference(y).advance(f))
1695 check_difference([], [], []);
1696 check_difference([1, 12], [], [1, 12]);
1697 check_difference([], [1, 2, 3, 9], []);
1698 check_difference([1, 3, 5, 9, 11],
1701 check_difference([-5, 11, 22, 33, 40, 42],
1702 [-12, -5, 14, 23, 34, 38, 39, 50],
1703 [11, 22, 33, 40, 42]);
1707 fn test_symmetric_difference() {
1708 fn check_symmetric_difference(a: &[int], b: &[int],
1710 check(a, b, expected, |x, y, f| x.symmetric_difference(y).advance(f))
1713 check_symmetric_difference([], [], []);
1714 check_symmetric_difference([1, 2, 3], [2], [1, 3]);
1715 check_symmetric_difference([2], [1, 2, 3], [1, 3]);
1716 check_symmetric_difference([1, 3, 5, 9, 11],
1718 [-2, 1, 5, 11, 14, 22]);
1723 fn check_union(a: &[int], b: &[int],
1725 check(a, b, expected, |x, y, f| x.union(y).advance(f))
1728 check_union([], [], []);
1729 check_union([1, 2, 3], [2], [1, 2, 3]);
1730 check_union([2], [1, 2, 3], [1, 2, 3]);
1731 check_union([1, 3, 5, 9, 11, 16, 19, 24],
1732 [-2, 1, 5, 9, 13, 19],
1733 [-2, 1, 3, 5, 9, 11, 13, 16, 19, 24]);
1738 let mut x = TreeSet::new();
1743 let mut y = TreeSet::new();
1749 let mut z = x.iter().zip(y.iter());
1751 // FIXME: #5801: this needs a type hint to compile...
1752 let result: Option<(&uint, & &'static str)> = z.next();
1753 assert_eq!(result.unwrap(), (&5u, &("bar")));
1755 let result: Option<(&uint, & &'static str)> = z.next();
1756 assert_eq!(result.unwrap(), (&11u, &("foo")));
1758 let result: Option<(&uint, & &'static str)> = z.next();
1759 assert!(result.is_none());
1764 let mut m = TreeMap::new();
1765 assert_eq!(m.swap(1, 2), None);
1766 assert_eq!(m.swap(1, 3), Some(2));
1767 assert_eq!(m.swap(1, 4), Some(3));
1772 let mut m = TreeMap::new();
1774 assert_eq!(m.pop(&1), Some(2));
1775 assert_eq!(m.pop(&1), None);
1779 fn test_from_iter() {
1780 let xs = [1, 2, 3, 4, 5, 6, 7, 8, 9];
1782 let set: TreeSet<int> = xs.iter().map(|&x| x).collect();
1784 for x in xs.iter() {
1785 assert!(set.contains(x));
1791 let mut set: TreeSet<int> = TreeSet::new();
1792 let empty: TreeSet<int> = TreeSet::new();
1797 let set_str = format!("{}", set);
1799 assert!(set_str == "{1, 2}".to_string());
1800 assert_eq!(format!("{}", empty), "{}".to_string());