1 // Copyright 2012-2014 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 //! An implementation of a set using a bit vector as an underlying
12 //! representation for holding unsigned numerical elements.
14 //! It should also be noted that the amount of storage necessary for holding a
15 //! set of objects is proportional to the maximum of the objects when viewed
21 //! use bit_set::BitSet;
23 //! // It's a regular set
24 //! let mut s = BitSet::new();
31 //! if !s.contains(7) {
32 //! println!("There is no 7");
35 //! // Can initialize from a `BitVec`
36 //! let other = BitSet::from_bytes(&[0b11010000]);
38 //! s.union_with(&other);
40 //! // Print 0, 1, 3 in some order
41 //! for x in s.iter() {
42 //! println!("{}", x);
45 //! // Can convert back to a `BitVec`
46 //! let bv = s.into_bit_vec();
50 #![cfg_attr(all(test, feature = "nightly"), feature(test))]
51 #[cfg(all(test, feature = "nightly"))] extern crate test;
52 #[cfg(all(test, feature = "nightly"))] extern crate rand;
55 use bit_vec::{BitVec, Blocks, BitBlock};
56 use std::cmp::Ordering;
60 use std::iter::{self, Chain, Enumerate, FromIterator, Repeat, Skip, Take};
62 type MatchWords<'a, B> = Chain<Enumerate<Blocks<'a, B>>, Skip<Take<Enumerate<Repeat<B>>>>>;
64 /// Computes how many blocks are needed to store that many bits
65 fn blocks_for_bits<B: BitBlock>(bits: usize) -> usize {
66 // If we want 17 bits, dividing by 32 will produce 0. So we add 1 to make sure we
67 // reserve enough. But if we want exactly a multiple of 32, this will actually allocate
68 // one too many. So we need to check if that's the case. We can do that by computing if
69 // bitwise AND by `32 - 1` is 0. But LLVM should be able to optimize the semantically
70 // superior modulo operator on a power of two to this.
72 // Note that we can technically avoid this branch with the expression
73 // `(nbits + BITS - 1) / 32::BITS`, but if nbits is almost usize::MAX this will overflow.
74 if bits % B::bits() == 0 {
81 // Take two BitVec's, and return iterators of their words, where the shorter one
82 // has been padded with 0's
83 fn match_words<'a, 'b, B: BitBlock>(a: &'a BitVec<B>, b: &'b BitVec<B>)
84 -> (MatchWords<'a, B>, MatchWords<'b, B>)
86 let a_len = a.storage().len();
87 let b_len = b.storage().len();
89 // have to uselessly pretend to pad the longer one for type matching
91 (a.blocks().enumerate().chain(iter::repeat(B::zero()).enumerate().take(b_len).skip(a_len)),
92 b.blocks().enumerate().chain(iter::repeat(B::zero()).enumerate().take(0).skip(0)))
94 (a.blocks().enumerate().chain(iter::repeat(B::zero()).enumerate().take(0).skip(0)),
95 b.blocks().enumerate().chain(iter::repeat(B::zero()).enumerate().take(a_len).skip(b_len)))
99 pub struct BitSet<B = u32> {
103 impl<B: BitBlock> Clone for BitSet<B> {
104 fn clone(&self) -> Self {
106 bit_vec: self.bit_vec.clone(),
110 fn clone_from(&mut self, other: &Self) {
111 self.bit_vec.clone_from(&other.bit_vec);
115 impl<B: BitBlock> Default for BitSet<B> {
117 fn default() -> Self { BitSet { bit_vec: Default::default() } }
120 impl<B: BitBlock> FromIterator<usize> for BitSet<B> {
121 fn from_iter<I: IntoIterator<Item = usize>>(iter: I) -> Self {
122 let mut ret = Self::default();
128 impl<B: BitBlock> Extend<usize> for BitSet<B> {
130 fn extend<I: IntoIterator<Item = usize>>(&mut self, iter: I) {
137 impl<B: BitBlock> PartialOrd for BitSet<B> {
139 fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
140 self.iter().partial_cmp(other)
144 impl<B: BitBlock> Ord for BitSet<B> {
146 fn cmp(&self, other: &Self) -> Ordering {
147 self.iter().cmp(other)
151 impl<B: BitBlock> PartialEq for BitSet<B> {
153 fn eq(&self, other: &Self) -> bool {
154 self.iter().eq(other)
158 impl<B: BitBlock> Eq for BitSet<B> {}
161 /// Creates a new empty `BitSet`.
166 /// use bit_set::BitSet;
168 /// let mut s = BitSet::new();
171 pub fn new() -> Self {
175 /// Creates a new `BitSet` with initially no contents, able to
176 /// hold `nbits` elements without resizing.
181 /// use bit_set::BitSet;
183 /// let mut s = BitSet::with_capacity(100);
184 /// assert!(s.capacity() >= 100);
187 pub fn with_capacity(nbits: usize) -> Self {
188 let bit_vec = BitVec::from_elem(nbits, false);
189 Self::from_bit_vec(bit_vec)
192 /// Creates a new `BitSet` from the given bit vector.
197 /// extern crate bit_vec;
198 /// extern crate bit_set;
201 /// use bit_vec::BitVec;
202 /// use bit_set::BitSet;
204 /// let bv = BitVec::from_bytes(&[0b01100000]);
205 /// let s = BitSet::from_bit_vec(bv);
207 /// // Print 1, 2 in arbitrary order
208 /// for x in s.iter() {
209 /// println!("{}", x);
214 pub fn from_bit_vec(bit_vec: BitVec) -> Self {
215 BitSet { bit_vec: bit_vec }
218 pub fn from_bytes(bytes: &[u8]) -> Self {
219 BitSet { bit_vec: BitVec::from_bytes(bytes) }
223 impl<B: BitBlock> BitSet<B> {
225 /// Returns the capacity in bits for this bit vector. Inserting any
226 /// element less than this amount will not trigger a resizing.
231 /// use bit_set::BitSet;
233 /// let mut s = BitSet::with_capacity(100);
234 /// assert!(s.capacity() >= 100);
237 pub fn capacity(&self) -> usize {
238 self.bit_vec.capacity()
241 /// Reserves capacity for the given `BitSet` to contain `len` distinct elements. In the case
242 /// of `BitSet` this means reallocations will not occur as long as all inserted elements
243 /// are less than `len`.
245 /// The collection may reserve more space to avoid frequent reallocations.
251 /// use bit_set::BitSet;
253 /// let mut s = BitSet::new();
254 /// s.reserve_len(10);
255 /// assert!(s.capacity() >= 10);
257 pub fn reserve_len(&mut self, len: usize) {
258 let cur_len = self.bit_vec.len();
260 self.bit_vec.reserve(len - cur_len);
264 /// Reserves the minimum capacity for the given `BitSet` to contain `len` distinct elements.
265 /// In the case of `BitSet` this means reallocations will not occur as long as all inserted
266 /// elements are less than `len`.
268 /// Note that the allocator may give the collection more space than it requests. Therefore
269 /// capacity can not be relied upon to be precisely minimal. Prefer `reserve_len` if future
270 /// insertions are expected.
276 /// use bit_set::BitSet;
278 /// let mut s = BitSet::new();
279 /// s.reserve_len_exact(10);
280 /// assert!(s.capacity() >= 10);
282 pub fn reserve_len_exact(&mut self, len: usize) {
283 let cur_len = self.bit_vec.len();
285 self.bit_vec.reserve_exact(len - cur_len);
289 /// Consumes this set to return the underlying bit vector.
294 /// use bit_set::BitSet;
296 /// let mut s = BitSet::new();
300 /// let bv = s.into_bit_vec();
305 pub fn into_bit_vec(self) -> BitVec<B> {
309 /// Returns a reference to the underlying bit vector.
314 /// use bit_set::BitSet;
316 /// let mut s = BitSet::new();
319 /// let bv = s.get_ref();
320 /// assert_eq!(bv[0], true);
323 pub fn get_ref(&self) -> &BitVec<B> {
328 fn other_op<F>(&mut self, other: &Self, mut f: F) where F: FnMut(B, B) -> B {
330 let self_bit_vec = &mut self.bit_vec;
331 let other_bit_vec = &other.bit_vec;
333 let self_len = self_bit_vec.len();
334 let other_len = other_bit_vec.len();
336 // Expand the vector if necessary
337 if self_len < other_len {
338 self_bit_vec.grow(other_len - self_len, false);
341 // virtually pad other with 0's for equal lengths
343 let (_, result) = match_words(self_bit_vec, other_bit_vec);
347 // Apply values found in other
348 for (i, w) in other_words {
349 let old = self_bit_vec.storage()[i];
352 self_bit_vec.storage_mut()[i] = new;
357 /// Truncates the underlying vector to the least length required.
362 /// use bit_set::BitSet;
364 /// let mut s = BitSet::new();
365 /// s.insert(32183231);
366 /// s.remove(32183231);
368 /// // Internal storage will probably be bigger than necessary
369 /// println!("old capacity: {}", s.capacity());
371 /// // Now should be smaller
372 /// s.shrink_to_fit();
373 /// println!("new capacity: {}", s.capacity());
376 pub fn shrink_to_fit(&mut self) {
377 let bit_vec = &mut self.bit_vec;
378 // Obtain original length
379 let old_len = bit_vec.storage().len();
380 // Obtain coarse trailing zero length
381 let n = bit_vec.storage().iter().rev().take_while(|&&n| n == B::zero()).count();
383 let trunc_len = cmp::max(old_len - n, 1);
385 bit_vec.storage_mut().truncate(trunc_len);
386 bit_vec.set_len(trunc_len * B::bits());
390 /// Iterator over each usize stored in the `BitSet`.
395 /// use bit_set::BitSet;
397 /// let s = BitSet::from_bytes(&[0b01001010]);
399 /// // Print 1, 4, 6 in arbitrary order
400 /// for x in s.iter() {
401 /// println!("{}", x);
405 pub fn iter(&self) -> Iter<B> {
406 Iter(BlockIter::from_blocks(self.bit_vec.blocks()))
409 /// Iterator over each usize stored in `self` union `other`.
410 /// See [union_with](#method.union_with) for an efficient in-place version.
415 /// use bit_set::BitSet;
417 /// let a = BitSet::from_bytes(&[0b01101000]);
418 /// let b = BitSet::from_bytes(&[0b10100000]);
420 /// // Print 0, 1, 2, 4 in arbitrary order
421 /// for x in a.union(&b) {
422 /// println!("{}", x);
426 pub fn union<'a>(&'a self, other: &'a Self) -> Union<'a, B> {
427 fn or<B: BitBlock>(w1: B, w2: B) -> B { w1 | w2 }
429 Union(BlockIter::from_blocks(TwoBitPositions {
430 set: self.bit_vec.blocks(),
431 other: other.bit_vec.blocks(),
436 /// Iterator over each usize stored in `self` intersect `other`.
437 /// See [intersect_with](#method.intersect_with) for an efficient in-place version.
442 /// use bit_set::BitSet;
444 /// let a = BitSet::from_bytes(&[0b01101000]);
445 /// let b = BitSet::from_bytes(&[0b10100000]);
448 /// for x in a.intersection(&b) {
449 /// println!("{}", x);
453 pub fn intersection<'a>(&'a self, other: &'a Self) -> Intersection<'a, B> {
454 fn bitand<B: BitBlock>(w1: B, w2: B) -> B { w1 & w2 }
455 let min = cmp::min(self.bit_vec.len(), other.bit_vec.len());
457 Intersection(BlockIter::from_blocks(TwoBitPositions {
458 set: self.bit_vec.blocks(),
459 other: other.bit_vec.blocks(),
464 /// Iterator over each usize stored in the `self` setminus `other`.
465 /// See [difference_with](#method.difference_with) for an efficient in-place version.
470 /// use bit_set::BitSet;
472 /// let a = BitSet::from_bytes(&[0b01101000]);
473 /// let b = BitSet::from_bytes(&[0b10100000]);
475 /// // Print 1, 4 in arbitrary order
476 /// for x in a.difference(&b) {
477 /// println!("{}", x);
480 /// // Note that difference is not symmetric,
481 /// // and `b - a` means something else.
483 /// for x in b.difference(&a) {
484 /// println!("{}", x);
488 pub fn difference<'a>(&'a self, other: &'a Self) -> Difference<'a, B> {
489 fn diff<B: BitBlock>(w1: B, w2: B) -> B { w1 & !w2 }
491 Difference(BlockIter::from_blocks(TwoBitPositions {
492 set: self.bit_vec.blocks(),
493 other: other.bit_vec.blocks(),
498 /// Iterator over each usize stored in the symmetric difference of `self` and `other`.
499 /// See [symmetric_difference_with](#method.symmetric_difference_with) for
500 /// an efficient in-place version.
505 /// use bit_set::BitSet;
507 /// let a = BitSet::from_bytes(&[0b01101000]);
508 /// let b = BitSet::from_bytes(&[0b10100000]);
510 /// // Print 0, 1, 4 in arbitrary order
511 /// for x in a.symmetric_difference(&b) {
512 /// println!("{}", x);
516 pub fn symmetric_difference<'a>(&'a self, other: &'a Self) -> SymmetricDifference<'a, B> {
517 fn bitxor<B: BitBlock>(w1: B, w2: B) -> B { w1 ^ w2 }
519 SymmetricDifference(BlockIter::from_blocks(TwoBitPositions {
520 set: self.bit_vec.blocks(),
521 other: other.bit_vec.blocks(),
526 /// Unions in-place with the specified other bit vector.
531 /// use bit_set::BitSet;
533 /// let a = 0b01101000;
534 /// let b = 0b10100000;
535 /// let res = 0b11101000;
537 /// let mut a = BitSet::from_bytes(&[a]);
538 /// let b = BitSet::from_bytes(&[b]);
539 /// let res = BitSet::from_bytes(&[res]);
541 /// a.union_with(&b);
542 /// assert_eq!(a, res);
545 pub fn union_with(&mut self, other: &Self) {
546 self.other_op(other, |w1, w2| w1 | w2);
549 /// Intersects in-place with the specified other bit vector.
554 /// use bit_set::BitSet;
556 /// let a = 0b01101000;
557 /// let b = 0b10100000;
558 /// let res = 0b00100000;
560 /// let mut a = BitSet::from_bytes(&[a]);
561 /// let b = BitSet::from_bytes(&[b]);
562 /// let res = BitSet::from_bytes(&[res]);
564 /// a.intersect_with(&b);
565 /// assert_eq!(a, res);
568 pub fn intersect_with(&mut self, other: &Self) {
569 self.other_op(other, |w1, w2| w1 & w2);
572 /// Makes this bit vector the difference with the specified other bit vector
578 /// use bit_set::BitSet;
580 /// let a = 0b01101000;
581 /// let b = 0b10100000;
582 /// let a_b = 0b01001000; // a - b
583 /// let b_a = 0b10000000; // b - a
585 /// let mut bva = BitSet::from_bytes(&[a]);
586 /// let bvb = BitSet::from_bytes(&[b]);
587 /// let bva_b = BitSet::from_bytes(&[a_b]);
588 /// let bvb_a = BitSet::from_bytes(&[b_a]);
590 /// bva.difference_with(&bvb);
591 /// assert_eq!(bva, bva_b);
593 /// let bva = BitSet::from_bytes(&[a]);
594 /// let mut bvb = BitSet::from_bytes(&[b]);
596 /// bvb.difference_with(&bva);
597 /// assert_eq!(bvb, bvb_a);
600 pub fn difference_with(&mut self, other: &Self) {
601 self.other_op(other, |w1, w2| w1 & !w2);
604 /// Makes this bit vector the symmetric difference with the specified other
605 /// bit vector in-place.
610 /// use bit_set::BitSet;
612 /// let a = 0b01101000;
613 /// let b = 0b10100000;
614 /// let res = 0b11001000;
616 /// let mut a = BitSet::from_bytes(&[a]);
617 /// let b = BitSet::from_bytes(&[b]);
618 /// let res = BitSet::from_bytes(&[res]);
620 /// a.symmetric_difference_with(&b);
621 /// assert_eq!(a, res);
624 pub fn symmetric_difference_with(&mut self, other: &Self) {
625 self.other_op(other, |w1, w2| w1 ^ w2);
629 /// Moves all elements from `other` into `Self`, leaving `other` empty.
634 /// use bit_set::BitSet;
636 /// let mut a = BitSet::new();
640 /// let mut b = BitSet::new();
645 /// a.append(&mut b);
647 /// assert_eq!(a.len(), 4);
648 /// assert_eq!(b.len(), 0);
649 /// assert_eq!(a, BitSet::from_bytes(&[0b01110010]));
651 pub fn append(&mut self, other: &mut Self) {
652 self.union_with(other);
656 /// Splits the `BitSet` into two at the given key including the key.
657 /// Retains the first part in-place while returning the second part.
662 /// use bit_set::BitSet;
664 /// let mut a = BitSet::new();
670 /// let b = a.split_off(3);
672 /// assert_eq!(a.len(), 2);
673 /// assert_eq!(b.len(), 2);
674 /// assert_eq!(a, BitSet::from_bytes(&[0b01100000]));
675 /// assert_eq!(b, BitSet::from_bytes(&[0b00010010]));
677 pub fn split_off(&mut self, at: usize) -> Self {
678 let mut other = BitSet::new();
681 swap(self, &mut other);
683 } else if at >= self.bit_vec.len() {
687 // Calculate block and bit at which to split
691 // Pad `other` with `w` zero blocks,
692 // append `self`'s blocks in the range from `w` to the end to `other`
693 other.bit_vec.storage_mut().extend(repeat(0u32).take(w)
694 .chain(self.bit_vec.storage()[w..].iter().cloned()));
695 other.bit_vec.nbits = self.bit_vec.nbits;
698 other.bit_vec.storage_mut()[w] &= !0 << b;
701 // Sets `bit_vec.len()` and fixes the last block as well
702 self.bit_vec.truncate(at);
708 /// Returns the number of set bits in this set.
710 pub fn len(&self) -> usize {
711 self.bit_vec.blocks().fold(0, |acc, n| acc + n.count_ones() as usize)
714 /// Returns whether there are no bits set in this set
716 pub fn is_empty(&self) -> bool {
720 /// Clears all bits in this set
722 pub fn clear(&mut self) {
723 self.bit_vec.clear();
726 /// Returns `true` if this set contains the specified integer.
728 pub fn contains(&self, value: usize) -> bool {
729 let bit_vec = &self.bit_vec;
730 value < bit_vec.len() && bit_vec[value]
733 /// Returns `true` if the set has no elements in common with `other`.
734 /// This is equivalent to checking for an empty intersection.
736 pub fn is_disjoint(&self, other: &Self) -> bool {
737 self.intersection(other).next().is_none()
740 /// Returns `true` if the set is a subset of another.
742 pub fn is_subset(&self, other: &Self) -> bool {
743 let self_bit_vec = &self.bit_vec;
744 let other_bit_vec = &other.bit_vec;
745 let other_blocks = blocks_for_bits::<B>(other_bit_vec.len());
747 // Check that `self` intersect `other` is self
748 self_bit_vec.blocks().zip(other_bit_vec.blocks()).all(|(w1, w2)| w1 & w2 == w1) &&
749 // Make sure if `self` has any more blocks than `other`, they're all 0
750 self_bit_vec.blocks().skip(other_blocks).all(|w| w == B::zero())
753 /// Returns `true` if the set is a superset of another.
755 pub fn is_superset(&self, other: &Self) -> bool {
756 other.is_subset(self)
759 /// Adds a value to the set. Returns `true` if the value was not already
760 /// present in the set.
761 pub fn insert(&mut self, value: usize) -> bool {
762 if self.contains(value) {
766 // Ensure we have enough space to hold the new element
767 let len = self.bit_vec.len();
769 self.bit_vec.grow(value - len + 1, false)
772 self.bit_vec.set(value, true);
776 /// Removes a value from the set. Returns `true` if the value was
777 /// present in the set.
778 pub fn remove(&mut self, value: usize) -> bool {
779 if !self.contains(value) {
783 self.bit_vec.set(value, false);
789 impl<B: BitBlock> fmt::Debug for BitSet<B> {
790 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
791 fmt.debug_set().entries(self).finish()
795 impl<B: BitBlock> hash::Hash for BitSet<B> {
796 fn hash<H: hash::Hasher>(&self, state: &mut H) {
804 struct BlockIter<T, B> {
810 impl<T, B: BitBlock> BlockIter<T, B> where T: Iterator<Item=B> {
811 fn from_blocks(mut blocks: T) -> BlockIter<T, B> {
812 let h = blocks.next().unwrap_or(B::zero());
813 BlockIter {tail: blocks, head: h, head_offset: 0}
817 /// An iterator combining two `BitSet` iterators.
819 struct TwoBitPositions<'a, B: 'a> {
821 other: Blocks<'a, B>,
822 merge: fn(B, B) -> B,
825 /// An iterator for `BitSet`.
827 pub struct Iter<'a, B: 'a>(BlockIter<Blocks<'a, B>, B>);
829 pub struct Union<'a, B: 'a>(BlockIter<TwoBitPositions<'a, B>, B>);
831 pub struct Intersection<'a, B: 'a>(Take<BlockIter<TwoBitPositions<'a, B>, B>>);
833 pub struct Difference<'a, B: 'a>(BlockIter<TwoBitPositions<'a, B>, B>);
835 pub struct SymmetricDifference<'a, B: 'a>(BlockIter<TwoBitPositions<'a, B>, B>);
837 impl<'a, T, B: BitBlock> Iterator for BlockIter<T, B> where T: Iterator<Item=B> {
840 fn next(&mut self) -> Option<usize> {
841 while self.head == B::zero() {
842 match self.tail.next() {
843 Some(w) => self.head = w,
846 self.head_offset += B::bits();
849 // from the current block, isolate the
850 // LSB and subtract 1, producing k:
851 // a block with a number of set bits
852 // equal to the index of the LSB
853 let k = (self.head & (!self.head + B::one())) - B::one();
854 // update block, removing the LSB
855 self.head = self.head & (self.head - B::one());
856 // return offset + (index of LSB)
857 Some(self.head_offset + (B::count_ones(k) as usize))
861 fn size_hint(&self) -> (usize, Option<usize>) {
862 match self.tail.size_hint() {
863 (_, Some(h)) => (0, Some(1 + h * B::bits())),
869 impl<'a, B: BitBlock> Iterator for TwoBitPositions<'a, B> {
872 fn next(&mut self) -> Option<B> {
873 match (self.set.next(), self.other.next()) {
874 (Some(a), Some(b)) => Some((self.merge)(a, b)),
875 (Some(a), None) => Some((self.merge)(a, B::zero())),
876 (None, Some(b)) => Some((self.merge)(B::zero(), b)),
882 fn size_hint(&self) -> (usize, Option<usize>) {
883 let (a, au) = self.set.size_hint();
884 let (b, bu) = self.other.size_hint();
886 let upper = match (au, bu) {
887 (Some(au), Some(bu)) => Some(cmp::max(au, bu)),
891 (cmp::max(a, b), upper)
895 impl<'a, B: BitBlock> Iterator for Iter<'a, B> {
898 #[inline] fn next(&mut self) -> Option<usize> { self.0.next() }
899 #[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.0.size_hint() }
902 impl<'a, B: BitBlock> Iterator for Union<'a, B> {
905 #[inline] fn next(&mut self) -> Option<usize> { self.0.next() }
906 #[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.0.size_hint() }
909 impl<'a, B: BitBlock> Iterator for Intersection<'a, B> {
912 #[inline] fn next(&mut self) -> Option<usize> { self.0.next() }
913 #[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.0.size_hint() }
916 impl<'a, B: BitBlock> Iterator for Difference<'a, B> {
919 #[inline] fn next(&mut self) -> Option<usize> { self.0.next() }
920 #[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.0.size_hint() }
923 impl<'a, B: BitBlock> Iterator for SymmetricDifference<'a, B> {
926 #[inline] fn next(&mut self) -> Option<usize> { self.0.next() }
927 #[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.0.size_hint() }
930 impl<'a, B: BitBlock> IntoIterator for &'a BitSet<B> {
932 type IntoIter = Iter<'a, B>;
934 fn into_iter(self) -> Iter<'a, B> {
941 use std::cmp::Ordering::{Equal, Greater, Less};
946 fn test_bit_set_show() {
947 let mut s = BitSet::new();
952 assert_eq!("{1, 2, 10, 50}", format!("{:?}", s));
956 fn test_bit_set_from_usizes() {
957 let usizes = vec![0, 2, 2, 3];
958 let a: BitSet = usizes.into_iter().collect();
959 let mut b = BitSet::new();
967 fn test_bit_set_iterator() {
968 let usizes = vec![0, 2, 2, 3];
969 let bit_vec: BitSet = usizes.into_iter().collect();
971 let idxs: Vec<_> = bit_vec.iter().collect();
972 assert_eq!(idxs, [0, 2, 3]);
974 let long: BitSet = (0..10000).filter(|&n| n % 2 == 0).collect();
975 let real: Vec<_> = (0..10000/2).map(|x| x*2).collect();
977 let idxs: Vec<_> = long.iter().collect();
978 assert_eq!(idxs, real);
982 fn test_bit_set_frombit_vec_init() {
983 let bools = [true, false];
984 let lengths = [10, 64, 100];
987 let bitset = BitSet::from_bit_vec(BitVec::from_elem(l, b));
988 assert_eq!(bitset.contains(1), b);
989 assert_eq!(bitset.contains((l-1)), b);
990 assert!(!bitset.contains(l));
996 fn test_bit_vec_masking() {
997 let b = BitVec::from_elem(140, true);
998 let mut bs = BitSet::from_bit_vec(b);
999 assert!(bs.contains(139));
1000 assert!(!bs.contains(140));
1001 assert!(bs.insert(150));
1002 assert!(!bs.contains(140));
1003 assert!(!bs.contains(149));
1004 assert!(bs.contains(150));
1005 assert!(!bs.contains(151));
1009 fn test_bit_set_basic() {
1010 let mut b = BitSet::new();
1011 assert!(b.insert(3));
1012 assert!(!b.insert(3));
1013 assert!(b.contains(3));
1014 assert!(b.insert(4));
1015 assert!(!b.insert(4));
1016 assert!(b.contains(3));
1017 assert!(b.insert(400));
1018 assert!(!b.insert(400));
1019 assert!(b.contains(400));
1020 assert_eq!(b.len(), 3);
1024 fn test_bit_set_intersection() {
1025 let mut a = BitSet::new();
1026 let mut b = BitSet::new();
1028 assert!(a.insert(11));
1029 assert!(a.insert(1));
1030 assert!(a.insert(3));
1031 assert!(a.insert(77));
1032 assert!(a.insert(103));
1033 assert!(a.insert(5));
1035 assert!(b.insert(2));
1036 assert!(b.insert(11));
1037 assert!(b.insert(77));
1038 assert!(b.insert(5));
1039 assert!(b.insert(3));
1041 let expected = [3, 5, 11, 77];
1042 let actual: Vec<_> = a.intersection(&b).collect();
1043 assert_eq!(actual, expected);
1047 fn test_bit_set_difference() {
1048 let mut a = BitSet::new();
1049 let mut b = BitSet::new();
1051 assert!(a.insert(1));
1052 assert!(a.insert(3));
1053 assert!(a.insert(5));
1054 assert!(a.insert(200));
1055 assert!(a.insert(500));
1057 assert!(b.insert(3));
1058 assert!(b.insert(200));
1060 let expected = [1, 5, 500];
1061 let actual: Vec<_> = a.difference(&b).collect();
1062 assert_eq!(actual, expected);
1066 fn test_bit_set_symmetric_difference() {
1067 let mut a = BitSet::new();
1068 let mut b = BitSet::new();
1070 assert!(a.insert(1));
1071 assert!(a.insert(3));
1072 assert!(a.insert(5));
1073 assert!(a.insert(9));
1074 assert!(a.insert(11));
1076 assert!(b.insert(3));
1077 assert!(b.insert(9));
1078 assert!(b.insert(14));
1079 assert!(b.insert(220));
1081 let expected = [1, 5, 11, 14, 220];
1082 let actual: Vec<_> = a.symmetric_difference(&b).collect();
1083 assert_eq!(actual, expected);
1087 fn test_bit_set_union() {
1088 let mut a = BitSet::new();
1089 let mut b = BitSet::new();
1090 assert!(a.insert(1));
1091 assert!(a.insert(3));
1092 assert!(a.insert(5));
1093 assert!(a.insert(9));
1094 assert!(a.insert(11));
1095 assert!(a.insert(160));
1096 assert!(a.insert(19));
1097 assert!(a.insert(24));
1098 assert!(a.insert(200));
1100 assert!(b.insert(1));
1101 assert!(b.insert(5));
1102 assert!(b.insert(9));
1103 assert!(b.insert(13));
1104 assert!(b.insert(19));
1106 let expected = [1, 3, 5, 9, 11, 13, 19, 24, 160, 200];
1107 let actual: Vec<_> = a.union(&b).collect();
1108 assert_eq!(actual, expected);
1112 fn test_bit_set_subset() {
1113 let mut set1 = BitSet::new();
1114 let mut set2 = BitSet::new();
1116 assert!(set1.is_subset(&set2)); // {} {}
1118 assert!(set1.is_subset(&set2)); // {} { 1 }
1120 assert!(set1.is_subset(&set2)); // {} { 1, 2 }
1122 assert!(set1.is_subset(&set2)); // { 2 } { 1, 2 }
1124 assert!(!set1.is_subset(&set2)); // { 2, 3 } { 1, 2 }
1126 assert!(set1.is_subset(&set2)); // { 2, 3 } { 1, 2, 3 }
1128 assert!(set1.is_subset(&set2)); // { 2, 3 } { 1, 2, 3, 4 }
1130 assert!(set1.is_subset(&set2)); // { 2, 3 } { 2, 3, 4 }
1132 assert!(!set1.is_subset(&set2)); // { 2, 3 } { 2, 4 }
1134 assert!(set1.is_subset(&set2)); // { 2 } { 2, 4 }
1138 fn test_bit_set_is_disjoint() {
1139 let a = BitSet::from_bytes(&[0b10100010]);
1140 let b = BitSet::from_bytes(&[0b01000000]);
1141 let c = BitSet::new();
1142 let d = BitSet::from_bytes(&[0b00110000]);
1144 assert!(!a.is_disjoint(&d));
1145 assert!(!d.is_disjoint(&a));
1147 assert!(a.is_disjoint(&b));
1148 assert!(a.is_disjoint(&c));
1149 assert!(b.is_disjoint(&a));
1150 assert!(b.is_disjoint(&c));
1151 assert!(c.is_disjoint(&a));
1152 assert!(c.is_disjoint(&b));
1156 fn test_bit_set_union_with() {
1157 //a should grow to include larger elements
1158 let mut a = BitSet::new();
1160 let mut b = BitSet::new();
1162 let expected = BitSet::from_bytes(&[0b10000100]);
1164 assert_eq!(a, expected);
1167 let mut a = BitSet::from_bytes(&[0b10100010]);
1168 let mut b = BitSet::from_bytes(&[0b01100010]);
1172 assert_eq!(a.len(), 4);
1173 assert_eq!(b.len(), 4);
1177 fn test_bit_set_intersect_with() {
1178 // Explicitly 0'ed bits
1179 let mut a = BitSet::from_bytes(&[0b10100010]);
1180 let mut b = BitSet::from_bytes(&[0b00000000]);
1182 a.intersect_with(&b);
1183 b.intersect_with(&c);
1184 assert!(a.is_empty());
1185 assert!(b.is_empty());
1187 // Uninitialized bits should behave like 0's
1188 let mut a = BitSet::from_bytes(&[0b10100010]);
1189 let mut b = BitSet::new();
1191 a.intersect_with(&b);
1192 b.intersect_with(&c);
1193 assert!(a.is_empty());
1194 assert!(b.is_empty());
1197 let mut a = BitSet::from_bytes(&[0b10100010]);
1198 let mut b = BitSet::from_bytes(&[0b01100010]);
1200 a.intersect_with(&b);
1201 b.intersect_with(&c);
1202 assert_eq!(a.len(), 2);
1203 assert_eq!(b.len(), 2);
1207 fn test_bit_set_difference_with() {
1208 // Explicitly 0'ed bits
1209 let mut a = BitSet::from_bytes(&[0b00000000]);
1210 let b = BitSet::from_bytes(&[0b10100010]);
1211 a.difference_with(&b);
1212 assert!(a.is_empty());
1214 // Uninitialized bits should behave like 0's
1215 let mut a = BitSet::new();
1216 let b = BitSet::from_bytes(&[0b11111111]);
1217 a.difference_with(&b);
1218 assert!(a.is_empty());
1221 let mut a = BitSet::from_bytes(&[0b10100010]);
1222 let mut b = BitSet::from_bytes(&[0b01100010]);
1224 a.difference_with(&b);
1225 b.difference_with(&c);
1226 assert_eq!(a.len(), 1);
1227 assert_eq!(b.len(), 1);
1231 fn test_bit_set_symmetric_difference_with() {
1232 //a should grow to include larger elements
1233 let mut a = BitSet::new();
1236 let mut b = BitSet::new();
1239 let expected = BitSet::from_bytes(&[0b10000100]);
1240 a.symmetric_difference_with(&b);
1241 assert_eq!(a, expected);
1243 let mut a = BitSet::from_bytes(&[0b10100010]);
1244 let b = BitSet::new();
1246 a.symmetric_difference_with(&b);
1250 let mut a = BitSet::from_bytes(&[0b11100010]);
1251 let mut b = BitSet::from_bytes(&[0b01101010]);
1253 a.symmetric_difference_with(&b);
1254 b.symmetric_difference_with(&c);
1255 assert_eq!(a.len(), 2);
1256 assert_eq!(b.len(), 2);
1260 fn test_bit_set_eq() {
1261 let a = BitSet::from_bytes(&[0b10100010]);
1262 let b = BitSet::from_bytes(&[0b00000000]);
1263 let c = BitSet::new();
1274 fn test_bit_set_cmp() {
1275 let a = BitSet::from_bytes(&[0b10100010]);
1276 let b = BitSet::from_bytes(&[0b00000000]);
1277 let c = BitSet::new();
1279 assert_eq!(a.cmp(&b), Greater);
1280 assert_eq!(a.cmp(&c), Greater);
1281 assert_eq!(b.cmp(&a), Less);
1282 assert_eq!(b.cmp(&c), Equal);
1283 assert_eq!(c.cmp(&a), Less);
1284 assert_eq!(c.cmp(&b), Equal);
1288 fn test_bit_vec_remove() {
1289 let mut a = BitSet::new();
1291 assert!(a.insert(1));
1292 assert!(a.remove(1));
1294 assert!(a.insert(100));
1295 assert!(a.remove(100));
1297 assert!(a.insert(1000));
1298 assert!(a.remove(1000));
1303 fn test_bit_vec_clone() {
1304 let mut a = BitSet::new();
1306 assert!(a.insert(1));
1307 assert!(a.insert(100));
1308 assert!(a.insert(1000));
1310 let mut b = a.clone();
1314 assert!(b.remove(1));
1315 assert!(a.contains(1));
1317 assert!(a.remove(1000));
1318 assert!(b.contains(1000));
1323 fn test_bit_set_append() {
1324 let mut a = BitSet::new();
1328 let mut b = BitSet::new();
1335 assert_eq!(a.len(), 4);
1336 assert_eq!(b.len(), 0);
1337 assert!(b.capacity() >= 6);
1339 assert_eq!(a, BitSet::from_bytes(&[0b01110010]));
1343 fn test_bit_set_split_off() {
1345 let mut a = BitSet::from_bytes(&[0b10100000, 0b00010010, 0b10010010,
1346 0b00110011, 0b01101011, 0b10101101]);
1348 let b = a.split_off(0);
1350 assert_eq!(a.len(), 0);
1351 assert_eq!(b.len(), 21);
1353 assert_eq!(b, BitSet::from_bytes(&[0b10100000, 0b00010010, 0b10010010,
1354 0b00110011, 0b01101011, 0b10101101]);
1356 // Split behind last element
1357 let mut a = BitSet::from_bytes(&[0b10100000, 0b00010010, 0b10010010,
1358 0b00110011, 0b01101011, 0b10101101]);
1360 let b = a.split_off(50);
1362 assert_eq!(a.len(), 21);
1363 assert_eq!(b.len(), 0);
1365 assert_eq!(a, BitSet::from_bytes(&[0b10100000, 0b00010010, 0b10010010,
1366 0b00110011, 0b01101011, 0b10101101]));
1368 // Split at arbitrary element
1369 let mut a = BitSet::from_bytes(&[0b10100000, 0b00010010, 0b10010010,
1370 0b00110011, 0b01101011, 0b10101101]);
1372 let b = a.split_off(34);
1374 assert_eq!(a.len(), 12);
1375 assert_eq!(b.len(), 9);
1377 assert_eq!(a, BitSet::from_bytes(&[0b10100000, 0b00010010, 0b10010010,
1378 0b00110011, 0b01000000]));
1379 assert_eq!(b, BitSet::from_bytes(&[0, 0, 0, 0,
1380 0b00101011, 0b10101101]));
1385 #[cfg(all(test, feature = "nightly"))]
1388 use bit_vec::BitVec;
1389 use rand::{Rng, thread_rng, ThreadRng};
1391 use test::{Bencher, black_box};
1393 const BENCH_BITS: usize = 1 << 14;
1394 const BITS: usize = 32;
1396 fn rng() -> ThreadRng {
1401 fn bench_bit_vecset_small(b: &mut Bencher) {
1403 let mut bit_vec = BitSet::new();
1406 bit_vec.insert((r.next_u32() as usize) % BITS);
1408 black_box(&bit_vec);
1413 fn bench_bit_vecset_big(b: &mut Bencher) {
1415 let mut bit_vec = BitSet::new();
1418 bit_vec.insert((r.next_u32() as usize) % BENCH_BITS);
1420 black_box(&bit_vec);
1425 fn bench_bit_vecset_iter(b: &mut Bencher) {
1426 let bit_vec = BitSet::from_bit_vec(BitVec::from_fn(BENCH_BITS,
1427 |idx| {idx % 3 == 0}));
1430 for idx in &bit_vec {
1431 sum += idx as usize;