1 // Copyright 2014 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 // This is pretty much entirely stolen from TreeSet, since BTreeMap has an identical interface
16 use core::borrow::BorrowFrom;
17 use core::cmp::Ordering::{self, Less, Greater, Equal};
18 use core::default::Default;
21 // NOTE(stage0) remove import after a snapshot
24 use core::iter::{Peekable, Map, FromIterator};
25 use core::ops::{BitOr, BitAnd, BitXor, Sub};
27 use btree_map::{BTreeMap, Keys};
29 // FIXME(conventions): implement bounded iterators
31 /// A set based on a B-Tree.
33 /// See BTreeMap's documentation for a detailed discussion of this collection's performance
34 /// benefits and drawbacks.
35 #[derive(Clone, Hash, PartialEq, Eq, Ord, PartialOrd)]
37 pub struct BTreeSet<T>{
41 /// An iterator over a BTreeSet's items.
43 pub struct Iter<'a, T: 'a> {
47 /// An owning iterator over a BTreeSet's items.
49 pub struct IntoIter<T> {
50 iter: Map<(T, ()), T, ::btree_map::IntoIter<T, ()>, fn((T, ())) -> T>
53 /// A lazy iterator producing elements in the set difference (in-order).
55 pub struct Difference<'a, T:'a> {
56 a: Peekable<&'a T, Iter<'a, T>>,
57 b: Peekable<&'a T, Iter<'a, T>>,
60 /// A lazy iterator producing elements in the set symmetric difference (in-order).
62 pub struct SymmetricDifference<'a, T:'a> {
63 a: Peekable<&'a T, Iter<'a, T>>,
64 b: Peekable<&'a T, Iter<'a, T>>,
67 /// A lazy iterator producing elements in the set intersection (in-order).
69 pub struct Intersection<'a, T:'a> {
70 a: Peekable<&'a T, Iter<'a, T>>,
71 b: Peekable<&'a T, Iter<'a, T>>,
74 /// A lazy iterator producing elements in the set union (in-order).
76 pub struct Union<'a, T:'a> {
77 a: Peekable<&'a T, Iter<'a, T>>,
78 b: Peekable<&'a T, Iter<'a, T>>,
81 impl<T: Ord> BTreeSet<T> {
82 /// Makes a new BTreeSet with a reasonable choice of B.
87 /// use std::collections::BTreeSet;
89 /// let mut set: BTreeSet<int> = BTreeSet::new();
92 pub fn new() -> BTreeSet<T> {
93 BTreeSet { map: BTreeMap::new() }
96 /// Makes a new BTreeSet with the given B.
98 /// B cannot be less than 2.
99 #[unstable = "probably want this to be on the type, eventually"]
100 pub fn with_b(b: uint) -> BTreeSet<T> {
101 BTreeSet { map: BTreeMap::with_b(b) }
105 impl<T> BTreeSet<T> {
106 /// Gets an iterator over the BTreeSet's contents.
111 /// use std::collections::BTreeSet;
113 /// let set: BTreeSet<uint> = [1u, 2, 3, 4].iter().map(|&x| x).collect();
115 /// for x in set.iter() {
116 /// println!("{}", x);
119 /// let v: Vec<uint> = set.iter().map(|&x| x).collect();
120 /// assert_eq!(v, vec![1u,2,3,4]);
123 pub fn iter(&self) -> Iter<T> {
124 Iter { iter: self.map.keys() }
127 /// Gets an iterator for moving out the BtreeSet's contents.
132 /// use std::collections::BTreeSet;
134 /// let set: BTreeSet<uint> = [1u, 2, 3, 4].iter().map(|&x| x).collect();
136 /// let v: Vec<uint> = set.into_iter().collect();
137 /// assert_eq!(v, vec![1u,2,3,4]);
140 pub fn into_iter(self) -> IntoIter<T> {
141 fn first<A, B>((a, _): (A, B)) -> A { a }
142 let first: fn((T, ())) -> T = first; // coerce to fn pointer
144 IntoIter { iter: self.map.into_iter().map(first) }
148 impl<T: Ord> BTreeSet<T> {
149 /// Visits the values representing the difference, in ascending order.
154 /// use std::collections::BTreeSet;
156 /// let mut a = BTreeSet::new();
160 /// let mut b = BTreeSet::new();
164 /// let diff: Vec<uint> = a.difference(&b).cloned().collect();
165 /// assert_eq!(diff, vec![1u]);
168 pub fn difference<'a>(&'a self, other: &'a BTreeSet<T>) -> Difference<'a, T> {
169 Difference{a: self.iter().peekable(), b: other.iter().peekable()}
172 /// Visits the values representing the symmetric difference, in ascending order.
177 /// use std::collections::BTreeSet;
179 /// let mut a = BTreeSet::new();
183 /// let mut b = BTreeSet::new();
187 /// let sym_diff: Vec<uint> = a.symmetric_difference(&b).cloned().collect();
188 /// assert_eq!(sym_diff, vec![1u,3]);
191 pub fn symmetric_difference<'a>(&'a self, other: &'a BTreeSet<T>)
192 -> SymmetricDifference<'a, T> {
193 SymmetricDifference{a: self.iter().peekable(), b: other.iter().peekable()}
196 /// Visits the values representing the intersection, in ascending order.
201 /// use std::collections::BTreeSet;
203 /// let mut a = BTreeSet::new();
207 /// let mut b = BTreeSet::new();
211 /// let intersection: Vec<uint> = a.intersection(&b).cloned().collect();
212 /// assert_eq!(intersection, vec![2u]);
215 pub fn intersection<'a>(&'a self, other: &'a BTreeSet<T>)
216 -> Intersection<'a, T> {
217 Intersection{a: self.iter().peekable(), b: other.iter().peekable()}
220 /// Visits the values representing the union, in ascending order.
225 /// use std::collections::BTreeSet;
227 /// let mut a = BTreeSet::new();
230 /// let mut b = BTreeSet::new();
233 /// let union: Vec<uint> = a.union(&b).cloned().collect();
234 /// assert_eq!(union, vec![1u,2]);
237 pub fn union<'a>(&'a self, other: &'a BTreeSet<T>) -> Union<'a, T> {
238 Union{a: self.iter().peekable(), b: other.iter().peekable()}
241 /// Return the number of elements in the set
246 /// use std::collections::BTreeSet;
248 /// let mut v = BTreeSet::new();
249 /// assert_eq!(v.len(), 0);
251 /// assert_eq!(v.len(), 1);
254 pub fn len(&self) -> uint { self.map.len() }
256 /// Returns true if the set contains no elements
261 /// use std::collections::BTreeSet;
263 /// let mut v = BTreeSet::new();
264 /// assert!(v.is_empty());
266 /// assert!(!v.is_empty());
269 pub fn is_empty(&self) -> bool { self.len() == 0 }
271 /// Clears the set, removing all values.
276 /// use std::collections::BTreeSet;
278 /// let mut v = BTreeSet::new();
281 /// assert!(v.is_empty());
284 pub fn clear(&mut self) {
288 /// Returns `true` if the set contains a value.
290 /// The value may be any borrowed form of the set's value type,
291 /// but the ordering on the borrowed form *must* match the
292 /// ordering on the value type.
297 /// use std::collections::BTreeSet;
299 /// let set: BTreeSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
300 /// assert_eq!(set.contains(&1), true);
301 /// assert_eq!(set.contains(&4), false);
304 pub fn contains<Q: ?Sized>(&self, value: &Q) -> bool where Q: BorrowFrom<T> + Ord {
305 self.map.contains_key(value)
308 /// Returns `true` if the set has no elements in common with `other`.
309 /// This is equivalent to checking for an empty intersection.
314 /// use std::collections::BTreeSet;
316 /// let a: BTreeSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
317 /// let mut b: BTreeSet<int> = BTreeSet::new();
319 /// assert_eq!(a.is_disjoint(&b), true);
321 /// assert_eq!(a.is_disjoint(&b), true);
323 /// assert_eq!(a.is_disjoint(&b), false);
326 pub fn is_disjoint(&self, other: &BTreeSet<T>) -> bool {
327 self.intersection(other).next().is_none()
330 /// Returns `true` if the set is a subset of another.
335 /// use std::collections::BTreeSet;
337 /// let sup: BTreeSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
338 /// let mut set: BTreeSet<int> = BTreeSet::new();
340 /// assert_eq!(set.is_subset(&sup), true);
342 /// assert_eq!(set.is_subset(&sup), true);
344 /// assert_eq!(set.is_subset(&sup), false);
347 pub fn is_subset(&self, other: &BTreeSet<T>) -> bool {
348 // Stolen from TreeMap
349 let mut x = self.iter();
350 let mut y = other.iter();
351 let mut a = x.next();
352 let mut b = y.next();
363 Greater => return false,
364 Equal => a = x.next(),
372 /// Returns `true` if the set is a superset of another.
377 /// use std::collections::BTreeSet;
379 /// let sub: BTreeSet<int> = [1i, 2].iter().map(|&x| x).collect();
380 /// let mut set: BTreeSet<int> = BTreeSet::new();
382 /// assert_eq!(set.is_superset(&sub), false);
386 /// assert_eq!(set.is_superset(&sub), false);
389 /// assert_eq!(set.is_superset(&sub), true);
392 pub fn is_superset(&self, other: &BTreeSet<T>) -> bool {
393 other.is_subset(self)
396 /// Adds a value to the set. Returns `true` if the value was not already
397 /// present in the set.
402 /// use std::collections::BTreeSet;
404 /// let mut set = BTreeSet::new();
406 /// assert_eq!(set.insert(2i), true);
407 /// assert_eq!(set.insert(2i), false);
408 /// assert_eq!(set.len(), 1);
411 pub fn insert(&mut self, value: T) -> bool {
412 self.map.insert(value, ()).is_none()
415 /// Removes a value from the set. Returns `true` if the value was
416 /// present in the set.
418 /// The value may be any borrowed form of the set's value type,
419 /// but the ordering on the borrowed form *must* match the
420 /// ordering on the value type.
425 /// use std::collections::BTreeSet;
427 /// let mut set = BTreeSet::new();
430 /// assert_eq!(set.remove(&2), true);
431 /// assert_eq!(set.remove(&2), false);
434 pub fn remove<Q: ?Sized>(&mut self, value: &Q) -> bool where Q: BorrowFrom<T> + Ord {
435 self.map.remove(value).is_some()
440 impl<T: Ord> FromIterator<T> for BTreeSet<T> {
441 fn from_iter<Iter: Iterator<Item=T>>(iter: Iter) -> BTreeSet<T> {
442 let mut set = BTreeSet::new();
449 impl<T: Ord> Extend<T> for BTreeSet<T> {
451 fn extend<Iter: Iterator<Item=T>>(&mut self, mut iter: Iter) {
459 impl<T: Ord> Default for BTreeSet<T> {
461 fn default() -> BTreeSet<T> {
467 impl<'a, 'b, T: Ord + Clone> Sub<&'b BTreeSet<T>> for &'a BTreeSet<T> {
468 type Output = BTreeSet<T>;
470 /// Returns the difference of `self` and `rhs` as a new `BTreeSet<T>`.
475 /// use std::collections::BTreeSet;
477 /// let a: BTreeSet<int> = vec![1, 2, 3].into_iter().collect();
478 /// let b: BTreeSet<int> = vec![3, 4, 5].into_iter().collect();
480 /// let result: BTreeSet<int> = &a - &b;
481 /// let result_vec: Vec<int> = result.into_iter().collect();
482 /// assert_eq!(result_vec, vec![1, 2]);
484 fn sub(self, rhs: &BTreeSet<T>) -> BTreeSet<T> {
485 self.difference(rhs).cloned().collect()
490 impl<'a, 'b, T: Ord + Clone> BitXor<&'b BTreeSet<T>> for &'a BTreeSet<T> {
491 type Output = BTreeSet<T>;
493 /// Returns the symmetric difference of `self` and `rhs` as a new `BTreeSet<T>`.
498 /// use std::collections::BTreeSet;
500 /// let a: BTreeSet<int> = vec![1, 2, 3].into_iter().collect();
501 /// let b: BTreeSet<int> = vec![2, 3, 4].into_iter().collect();
503 /// let result: BTreeSet<int> = &a ^ &b;
504 /// let result_vec: Vec<int> = result.into_iter().collect();
505 /// assert_eq!(result_vec, vec![1, 4]);
507 fn bitxor(self, rhs: &BTreeSet<T>) -> BTreeSet<T> {
508 self.symmetric_difference(rhs).cloned().collect()
513 impl<'a, 'b, T: Ord + Clone> BitAnd<&'b BTreeSet<T>> for &'a BTreeSet<T> {
514 type Output = BTreeSet<T>;
516 /// Returns the intersection of `self` and `rhs` as a new `BTreeSet<T>`.
521 /// use std::collections::BTreeSet;
523 /// let a: BTreeSet<int> = vec![1, 2, 3].into_iter().collect();
524 /// let b: BTreeSet<int> = vec![2, 3, 4].into_iter().collect();
526 /// let result: BTreeSet<int> = &a & &b;
527 /// let result_vec: Vec<int> = result.into_iter().collect();
528 /// assert_eq!(result_vec, vec![2, 3]);
530 fn bitand(self, rhs: &BTreeSet<T>) -> BTreeSet<T> {
531 self.intersection(rhs).cloned().collect()
536 impl<'a, 'b, T: Ord + Clone> BitOr<&'b BTreeSet<T>> for &'a BTreeSet<T> {
537 type Output = BTreeSet<T>;
539 /// Returns the union of `self` and `rhs` as a new `BTreeSet<T>`.
544 /// use std::collections::BTreeSet;
546 /// let a: BTreeSet<int> = vec![1, 2, 3].into_iter().collect();
547 /// let b: BTreeSet<int> = vec![3, 4, 5].into_iter().collect();
549 /// let result: BTreeSet<int> = &a | &b;
550 /// let result_vec: Vec<int> = result.into_iter().collect();
551 /// assert_eq!(result_vec, vec![1, 2, 3, 4, 5]);
553 fn bitor(self, rhs: &BTreeSet<T>) -> BTreeSet<T> {
554 self.union(rhs).cloned().collect()
559 impl<T: Show> Show for BTreeSet<T> {
560 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
561 try!(write!(f, "BTreeSet {{"));
563 for (i, x) in self.iter().enumerate() {
564 if i != 0 { try!(write!(f, ", ")); }
565 try!(write!(f, "{:?}", *x));
573 impl<'a, T> Iterator for Iter<'a, T> {
576 fn next(&mut self) -> Option<&'a T> { self.iter.next() }
577 fn size_hint(&self) -> (uint, Option<uint>) { self.iter.size_hint() }
580 impl<'a, T> DoubleEndedIterator for Iter<'a, T> {
581 fn next_back(&mut self) -> Option<&'a T> { self.iter.next_back() }
584 impl<'a, T> ExactSizeIterator for Iter<'a, T> {}
588 impl<T> Iterator for IntoIter<T> {
591 fn next(&mut self) -> Option<T> { self.iter.next() }
592 fn size_hint(&self) -> (uint, Option<uint>) { self.iter.size_hint() }
595 impl<T> DoubleEndedIterator for IntoIter<T> {
596 fn next_back(&mut self) -> Option<T> { self.iter.next_back() }
599 impl<T> ExactSizeIterator for IntoIter<T> {}
601 /// Compare `x` and `y`, but return `short` if x is None and `long` if y is None
602 fn cmp_opt<T: Ord>(x: Option<&T>, y: Option<&T>,
603 short: Ordering, long: Ordering) -> Ordering {
605 (None , _ ) => short,
607 (Some(x1), Some(y1)) => x1.cmp(y1),
612 impl<'a, T: Ord> Iterator for Difference<'a, T> {
615 fn next(&mut self) -> Option<&'a T> {
617 match cmp_opt(self.a.peek(), self.b.peek(), Less, Less) {
618 Less => return self.a.next(),
619 Equal => { self.a.next(); self.b.next(); }
620 Greater => { self.b.next(); }
627 impl<'a, T: Ord> Iterator for SymmetricDifference<'a, T> {
630 fn next(&mut self) -> Option<&'a T> {
632 match cmp_opt(self.a.peek(), self.b.peek(), Greater, Less) {
633 Less => return self.a.next(),
634 Equal => { self.a.next(); self.b.next(); }
635 Greater => return self.b.next(),
642 impl<'a, T: Ord> Iterator for Intersection<'a, T> {
645 fn next(&mut self) -> Option<&'a T> {
647 let o_cmp = match (self.a.peek(), self.b.peek()) {
650 (Some(a1), Some(b1)) => Some(a1.cmp(b1)),
654 Some(Less) => { self.a.next(); }
655 Some(Equal) => { self.b.next(); return self.a.next() }
656 Some(Greater) => { self.b.next(); }
663 impl<'a, T: Ord> Iterator for Union<'a, T> {
666 fn next(&mut self) -> Option<&'a T> {
668 match cmp_opt(self.a.peek(), self.b.peek(), Greater, Less) {
669 Less => return self.a.next(),
670 Equal => { self.b.next(); return self.a.next() }
671 Greater => return self.b.next(),
683 use std::hash::{self, SipHasher};
687 let mut m = BTreeSet::new();
692 assert!(m.clone() == m);
697 let mut x = BTreeSet::new();
698 let mut y = BTreeSet::new();
708 assert!(hash::hash::<_, SipHasher>(&x) == hash::hash::<_, SipHasher>(&y));
711 struct Counter<'a, 'b> {
716 impl<'a, 'b, 'c> FnMut(&'c int) -> bool for Counter<'a, 'b> {
717 extern "rust-call" fn call_mut(&mut self, (&x,): (&'c int,)) -> bool {
718 assert_eq!(x, self.expected[*self.i]);
724 fn check<F>(a: &[int], b: &[int], expected: &[int], f: F) where
725 // FIXME Replace Counter with `Box<FnMut(_) -> _>`
726 F: FnOnce(&BTreeSet<int>, &BTreeSet<int>, Counter) -> bool,
728 let mut set_a = BTreeSet::new();
729 let mut set_b = BTreeSet::new();
731 for x in a.iter() { assert!(set_a.insert(*x)) }
732 for y in b.iter() { assert!(set_b.insert(*y)) }
735 f(&set_a, &set_b, Counter { i: &mut i, expected: expected });
736 assert_eq!(i, expected.len());
740 fn test_intersection() {
741 fn check_intersection(a: &[int], b: &[int], expected: &[int]) {
742 check(a, b, expected, |x, y, f| x.intersection(y).all(f))
745 check_intersection(&[], &[], &[]);
746 check_intersection(&[1, 2, 3], &[], &[]);
747 check_intersection(&[], &[1, 2, 3], &[]);
748 check_intersection(&[2], &[1, 2, 3], &[2]);
749 check_intersection(&[1, 2, 3], &[2], &[2]);
750 check_intersection(&[11, 1, 3, 77, 103, 5, -5],
751 &[2, 11, 77, -9, -42, 5, 3],
756 fn test_difference() {
757 fn check_difference(a: &[int], b: &[int], expected: &[int]) {
758 check(a, b, expected, |x, y, f| x.difference(y).all(f))
761 check_difference(&[], &[], &[]);
762 check_difference(&[1, 12], &[], &[1, 12]);
763 check_difference(&[], &[1, 2, 3, 9], &[]);
764 check_difference(&[1, 3, 5, 9, 11],
767 check_difference(&[-5, 11, 22, 33, 40, 42],
768 &[-12, -5, 14, 23, 34, 38, 39, 50],
769 &[11, 22, 33, 40, 42]);
773 fn test_symmetric_difference() {
774 fn check_symmetric_difference(a: &[int], b: &[int],
776 check(a, b, expected, |x, y, f| x.symmetric_difference(y).all(f))
779 check_symmetric_difference(&[], &[], &[]);
780 check_symmetric_difference(&[1, 2, 3], &[2], &[1, 3]);
781 check_symmetric_difference(&[2], &[1, 2, 3], &[1, 3]);
782 check_symmetric_difference(&[1, 3, 5, 9, 11],
784 &[-2, 1, 5, 11, 14, 22]);
789 fn check_union(a: &[int], b: &[int],
791 check(a, b, expected, |x, y, f| x.union(y).all(f))
794 check_union(&[], &[], &[]);
795 check_union(&[1, 2, 3], &[2], &[1, 2, 3]);
796 check_union(&[2], &[1, 2, 3], &[1, 2, 3]);
797 check_union(&[1, 3, 5, 9, 11, 16, 19, 24],
798 &[-2, 1, 5, 9, 13, 19],
799 &[-2, 1, 3, 5, 9, 11, 13, 16, 19, 24]);
804 let mut x = BTreeSet::new();
809 let mut y = BTreeSet::new();
815 let mut z = x.iter().zip(y.iter());
817 // FIXME: #5801: this needs a type hint to compile...
818 let result: Option<(&uint, & &'static str)> = z.next();
819 assert_eq!(result.unwrap(), (&5u, &("bar")));
821 let result: Option<(&uint, & &'static str)> = z.next();
822 assert_eq!(result.unwrap(), (&11u, &("foo")));
824 let result: Option<(&uint, & &'static str)> = z.next();
825 assert!(result.is_none());
829 fn test_from_iter() {
830 let xs = [1i, 2, 3, 4, 5, 6, 7, 8, 9];
832 let set: BTreeSet<int> = xs.iter().map(|&x| x).collect();
835 assert!(set.contains(x));
841 let mut set: BTreeSet<int> = BTreeSet::new();
842 let empty: BTreeSet<int> = BTreeSet::new();
847 let set_str = format!("{:?}", set);
849 assert_eq!(set_str, "BTreeSet {1i, 2i}");
850 assert_eq!(format!("{:?}", empty), "BTreeSet {}");