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 // FIXME(Gankro): Bitv and BitvSet are very tightly coupled. Ideally (for
12 // maintenance), they should be in separate files/modules, with BitvSet only
13 // using Bitv's public API. This will be hard for performance though, because
14 // `Bitv` will not want to leak its internal representation while its internal
15 // representation as `u32`s must be assumed for best performance.
17 // FIXME(tbu-): `Bitv`'s methods shouldn't be `union`, `intersection`, but
18 // rather `or` and `and`.
20 // (1) Be careful, most things can overflow here because the amount of bits in
21 // memory can overflow `uint`.
22 // (2) Make sure that the underlying vector has no excess length:
23 // E. g. `nbits == 16`, `storage.len() == 2` would be excess length,
24 // because the last word isn't used at all. This is important because some
25 // methods rely on it (for *CORRECTNESS*).
26 // (3) Make sure that the unused bits in the last word are zeroed out, again
27 // other methods rely on it for *CORRECTNESS*.
28 // (4) `BitvSet` is tightly coupled with `Bitv`, so any changes you make in
29 // `Bitv` will need to be reflected in `BitvSet`.
31 //! Collections implemented with bit vectors.
35 //! This is a simple example of the [Sieve of Eratosthenes][sieve]
36 //! which calculates prime numbers up to a given limit.
38 //! [sieve]: http://en.wikipedia.org/wiki/Sieve_of_Eratosthenes
41 //! use std::collections::{BitvSet, Bitv};
42 //! use std::num::Float;
45 //! let max_prime = 10000;
47 //! // Store the primes as a BitvSet
49 //! // Assume all numbers are prime to begin, and then we
50 //! // cross off non-primes progressively
51 //! let mut bv = Bitv::from_elem(max_prime, true);
53 //! // Neither 0 nor 1 are prime
57 //! for i in iter::range_inclusive(2, (max_prime as f64).sqrt() as uint) {
58 //! // if i is a prime
60 //! // Mark all multiples of i as non-prime (any multiples below i * i
61 //! // will have been marked as non-prime previously)
62 //! for j in iter::range_step(i * i, max_prime, i) { bv.set(j, false) }
65 //! BitvSet::from_bitv(bv)
68 //! // Simple primality tests below our max bound
69 //! let print_primes = 20;
70 //! print!("The primes below {} are: ", print_primes);
71 //! for x in range(0, print_primes) {
72 //! if primes.contains(&x) {
78 //! // We can manipulate the internal Bitv
79 //! let num_primes = primes.get_ref().iter().filter(|x| *x).count();
80 //! println!("There are {} primes below {}", num_primes, max_prime);
85 use core::cmp::Ordering;
87 use core::default::Default;
90 use core::iter::RandomAccessIterator;
91 use core::iter::{Chain, Enumerate, Repeat, Skip, Take, repeat, Cloned};
92 use core::iter::{mod, FromIterator};
96 use core::{u8, u32, uint};
97 use bitv_set; //so meta
101 type Blocks<'a> = Cloned<slice::Iter<'a, u32>>;
102 type MutBlocks<'a> = slice::IterMut<'a, u32>;
103 type MatchWords<'a> = Chain<Enumerate<Blocks<'a>>, Skip<Take<Enumerate<Repeat<u32>>>>>;
105 fn reverse_bits(byte: u8) -> u8 {
107 for i in range(0, u8::BITS) {
108 result |= ((byte >> i) & 1) << (u8::BITS - 1 - i);
113 // Take two BitV's, and return iterators of their words, where the shorter one
114 // has been padded with 0's
115 fn match_words <'a,'b>(a: &'a Bitv, b: &'b Bitv) -> (MatchWords<'a>, MatchWords<'b>) {
116 let a_len = a.storage.len();
117 let b_len = b.storage.len();
119 // have to uselessly pretend to pad the longer one for type matching
121 (a.blocks().enumerate().chain(iter::repeat(0u32).enumerate().take(b_len).skip(a_len)),
122 b.blocks().enumerate().chain(iter::repeat(0u32).enumerate().take(0).skip(0)))
124 (a.blocks().enumerate().chain(iter::repeat(0u32).enumerate().take(0).skip(0)),
125 b.blocks().enumerate().chain(iter::repeat(0u32).enumerate().take(a_len).skip(b_len)))
129 static TRUE: bool = true;
130 static FALSE: bool = false;
132 /// The bitvector type.
137 /// use collections::Bitv;
139 /// let mut bv = Bitv::from_elem(10, false);
141 /// // insert all primes less than 10
146 /// println!("{}", bv.to_string());
147 /// println!("total bits set to true: {}", bv.iter().filter(|x| *x).count());
149 /// // flip all values in bitvector, producing non-primes less than 10
151 /// println!("{}", bv.to_string());
152 /// println!("total bits set to true: {}", bv.iter().filter(|x| *x).count());
154 /// // reset bitvector to empty
156 /// println!("{}", bv.to_string());
157 /// println!("total bits set to true: {}", bv.iter().filter(|x| *x).count());
161 /// Internal representation of the bit vector
163 /// The number of valid bits in the internal representation
167 // NOTE(stage0): remove impl after a snapshot
169 // FIXME(Gankro): NopeNopeNopeNopeNope (wait for IndexGet to be a thing)
170 impl Index<uint,bool> for Bitv {
172 fn index(&self, i: &uint) -> &bool {
173 if self.get(*i).expect("index out of bounds") {
181 #[cfg(not(stage0))] // NOTE(stage0): remove cfg after a snapshot
182 // FIXME(Gankro): NopeNopeNopeNopeNope (wait for IndexGet to be a thing)
183 impl Index<uint> for Bitv {
187 fn index(&self, i: &uint) -> &bool {
188 if self.get(*i).expect("index out of bounds") {
196 /// Computes how many blocks are needed to store that many bits
197 fn blocks_for_bits(bits: uint) -> uint {
198 // If we want 17 bits, dividing by 32 will produce 0. So we add 1 to make sure we
199 // reserve enough. But if we want exactly a multiple of 32, this will actually allocate
200 // one too many. So we need to check if that's the case. We can do that by computing if
201 // bitwise AND by `32 - 1` is 0. But LLVM should be able to optimize the semantically
202 // superior modulo operator on a power of two to this.
204 // Note that we can technically avoid this branch with the expression
205 // `(nbits + u32::BITS - 1) / 32::BITS`, but if nbits is almost uint::MAX this will overflow.
206 if bits % u32::BITS == 0 {
213 /// Computes the bitmask for the final word of the vector
214 fn mask_for_bits(bits: uint) -> u32 {
215 // Note especially that a perfect multiple of u32::BITS should mask all 1s.
216 !0u32 >> (u32::BITS - bits % u32::BITS) % u32::BITS
220 /// Applies the given operation to the blocks of self and other, and sets
221 /// self to be the result. This relies on the caller not to corrupt the
224 fn process<F>(&mut self, other: &Bitv, mut op: F) -> bool where F: FnMut(u32, u32) -> u32 {
225 assert_eq!(self.len(), other.len());
226 // This could theoretically be a `debug_assert!`.
227 assert_eq!(self.storage.len(), other.storage.len());
228 let mut changed = false;
229 for (a, b) in self.blocks_mut().zip(other.blocks()) {
239 /// Iterator over mutable refs to the underlying blocks of data.
240 fn blocks_mut(&mut self) -> MutBlocks {
242 self.storage.iter_mut()
245 /// Iterator over the underlying blocks of data
246 fn blocks(&self) -> Blocks {
248 self.storage.iter().cloned()
251 /// An operation might screw up the unused bits in the last block of the
252 /// `Bitv`. As per (3), it's assumed to be all 0s. This method fixes it up.
253 fn fix_last_block(&mut self) {
254 let extra_bits = self.len() % u32::BITS;
256 let mask = (1 << extra_bits) - 1;
257 let storage_len = self.storage.len();
258 self.storage[storage_len - 1] &= mask;
262 /// Creates an empty `Bitv`.
267 /// use std::collections::Bitv;
268 /// let mut bv = Bitv::new();
271 pub fn new() -> Bitv {
272 Bitv { storage: Vec::new(), nbits: 0 }
275 /// Creates a `Bitv` that holds `nbits` elements, setting each element
281 /// use std::collections::Bitv;
283 /// let mut bv = Bitv::from_elem(10u, false);
284 /// assert_eq!(bv.len(), 10u);
285 /// for x in bv.iter() {
286 /// assert_eq!(x, false);
289 pub fn from_elem(nbits: uint, bit: bool) -> Bitv {
290 let nblocks = blocks_for_bits(nbits);
291 let mut bitv = Bitv {
292 storage: repeat(if bit { !0u32 } else { 0u32 }).take(nblocks).collect(),
295 bitv.fix_last_block();
299 /// Constructs a new, empty `Bitv` with the specified capacity.
301 /// The bitvector will be able to hold at least `capacity` bits without
302 /// reallocating. If `capacity` is 0, it will not allocate.
304 /// It is important to note that this function does not specify the
305 /// *length* of the returned bitvector, but only the *capacity*.
307 pub fn with_capacity(nbits: uint) -> Bitv {
309 storage: Vec::with_capacity(blocks_for_bits(nbits)),
314 /// Transforms a byte-vector into a `Bitv`. Each byte becomes eight bits,
315 /// with the most significant bits of each byte coming first. Each
316 /// bit becomes `true` if equal to 1 or `false` if equal to 0.
321 /// use std::collections::Bitv;
323 /// let bv = Bitv::from_bytes(&[0b10100000, 0b00010010]);
324 /// assert!(bv.eq_vec(&[true, false, true, false,
325 /// false, false, false, false,
326 /// false, false, false, true,
327 /// false, false, true, false]));
329 pub fn from_bytes(bytes: &[u8]) -> Bitv {
330 let len = bytes.len().checked_mul(u8::BITS).expect("capacity overflow");
331 let mut bitv = Bitv::with_capacity(len);
332 let complete_words = bytes.len() / 4;
333 let extra_bytes = bytes.len() % 4;
337 for i in range(0, complete_words) {
339 ((reverse_bits(bytes[i * 4 + 0]) as u32) << 0) |
340 ((reverse_bits(bytes[i * 4 + 1]) as u32) << 8) |
341 ((reverse_bits(bytes[i * 4 + 2]) as u32) << 16) |
342 ((reverse_bits(bytes[i * 4 + 3]) as u32) << 24)
347 let mut last_word = 0u32;
348 for (i, &byte) in bytes[complete_words*4..].iter().enumerate() {
349 last_word |= (reverse_bits(byte) as u32) << (i * 8);
351 bitv.storage.push(last_word);
357 /// Creates a `Bitv` of the specified length where the value at each index
363 /// use std::collections::Bitv;
365 /// let bv = Bitv::from_fn(5, |i| { i % 2 == 0 });
366 /// assert!(bv.eq_vec(&[true, false, true, false, true]));
368 pub fn from_fn<F>(len: uint, mut f: F) -> Bitv where F: FnMut(uint) -> bool {
369 let mut bitv = Bitv::from_elem(len, false);
370 for i in range(0u, len) {
376 /// Retrieves the value at index `i`, or `None` if the index is out of bounds.
381 /// use std::collections::Bitv;
383 /// let bv = Bitv::from_bytes(&[0b01100000]);
384 /// assert_eq!(bv.get(0), Some(false));
385 /// assert_eq!(bv.get(1), Some(true));
386 /// assert_eq!(bv.get(100), None);
388 /// // Can also use array indexing
389 /// assert_eq!(bv[1], true);
393 pub fn get(&self, i: uint) -> Option<bool> {
397 let w = i / u32::BITS;
398 let b = i % u32::BITS;
399 self.storage.get(w).map(|&block|
400 (block & (1 << b)) != 0
404 /// Sets the value of a bit at an index `i`.
408 /// Panics if `i` is out of bounds.
413 /// use std::collections::Bitv;
415 /// let mut bv = Bitv::from_elem(5, false);
417 /// assert_eq!(bv[3], true);
420 #[unstable = "panic semantics are likely to change in the future"]
421 pub fn set(&mut self, i: uint, x: bool) {
422 assert!(i < self.nbits);
423 let w = i / u32::BITS;
424 let b = i % u32::BITS;
426 let val = if x { self.storage[w] | flag }
427 else { self.storage[w] & !flag };
428 self.storage[w] = val;
431 /// Sets all bits to 1.
436 /// use std::collections::Bitv;
438 /// let before = 0b01100000;
439 /// let after = 0b11111111;
441 /// let mut bv = Bitv::from_bytes(&[before]);
443 /// assert_eq!(bv, Bitv::from_bytes(&[after]));
446 pub fn set_all(&mut self) {
447 for w in self.storage.iter_mut() { *w = !0u32; }
448 self.fix_last_block();
456 /// use std::collections::Bitv;
458 /// let before = 0b01100000;
459 /// let after = 0b10011111;
461 /// let mut bv = Bitv::from_bytes(&[before]);
463 /// assert_eq!(bv, Bitv::from_bytes(&[after]));
466 pub fn negate(&mut self) {
467 for w in self.storage.iter_mut() { *w = !*w; }
468 self.fix_last_block();
471 /// Calculates the union of two bitvectors. This acts like the bitwise `or`
474 /// Sets `self` to the union of `self` and `other`. Both bitvectors must be
475 /// the same length. Returns `true` if `self` changed.
479 /// Panics if the bitvectors are of different lengths.
484 /// use std::collections::Bitv;
486 /// let a = 0b01100100;
487 /// let b = 0b01011010;
488 /// let res = 0b01111110;
490 /// let mut a = Bitv::from_bytes(&[a]);
491 /// let b = Bitv::from_bytes(&[b]);
493 /// assert!(a.union(&b));
494 /// assert_eq!(a, Bitv::from_bytes(&[res]));
497 pub fn union(&mut self, other: &Bitv) -> bool {
498 self.process(other, |w1, w2| w1 | w2)
501 /// Calculates the intersection of two bitvectors. This acts like the
502 /// bitwise `and` function.
504 /// Sets `self` to the intersection of `self` and `other`. Both bitvectors
505 /// must be the same length. Returns `true` if `self` changed.
509 /// Panics if the bitvectors are of different lengths.
514 /// use std::collections::Bitv;
516 /// let a = 0b01100100;
517 /// let b = 0b01011010;
518 /// let res = 0b01000000;
520 /// let mut a = Bitv::from_bytes(&[a]);
521 /// let b = Bitv::from_bytes(&[b]);
523 /// assert!(a.intersect(&b));
524 /// assert_eq!(a, Bitv::from_bytes(&[res]));
527 pub fn intersect(&mut self, other: &Bitv) -> bool {
528 self.process(other, |w1, w2| w1 & w2)
531 /// Calculates the difference between two bitvectors.
533 /// Sets each element of `self` to the value of that element minus the
534 /// element of `other` at the same index. Both bitvectors must be the same
535 /// length. Returns `true` if `self` changed.
539 /// Panics if the bitvectors are of different length.
544 /// use std::collections::Bitv;
546 /// let a = 0b01100100;
547 /// let b = 0b01011010;
548 /// let a_b = 0b00100100; // a - b
549 /// let b_a = 0b00011010; // b - a
551 /// let mut bva = Bitv::from_bytes(&[a]);
552 /// let bvb = Bitv::from_bytes(&[b]);
554 /// assert!(bva.difference(&bvb));
555 /// assert_eq!(bva, Bitv::from_bytes(&[a_b]));
557 /// let bva = Bitv::from_bytes(&[a]);
558 /// let mut bvb = Bitv::from_bytes(&[b]);
560 /// assert!(bvb.difference(&bva));
561 /// assert_eq!(bvb, Bitv::from_bytes(&[b_a]));
564 pub fn difference(&mut self, other: &Bitv) -> bool {
565 self.process(other, |w1, w2| w1 & !w2)
568 /// Returns `true` if all bits are 1.
573 /// use std::collections::Bitv;
575 /// let mut bv = Bitv::from_elem(5, true);
576 /// assert_eq!(bv.all(), true);
578 /// bv.set(1, false);
579 /// assert_eq!(bv.all(), false);
581 pub fn all(&self) -> bool {
582 let mut last_word = !0u32;
583 // Check that every block but the last is all-ones...
584 self.blocks().all(|elem| {
588 // and then check the last one has enough ones
589 }) && (last_word == mask_for_bits(self.nbits))
592 /// Returns an iterator over the elements of the vector in order.
597 /// use std::collections::Bitv;
599 /// let bv = Bitv::from_bytes(&[0b01110100, 0b10010010]);
600 /// assert_eq!(bv.iter().filter(|x| *x).count(), 7);
604 pub fn iter(&self) -> Iter {
605 Iter { bitv: self, next_idx: 0, end_idx: self.nbits }
608 /// Returns `true` if all bits are 0.
613 /// use std::collections::Bitv;
615 /// let mut bv = Bitv::from_elem(10, false);
616 /// assert_eq!(bv.none(), true);
619 /// assert_eq!(bv.none(), false);
621 pub fn none(&self) -> bool {
622 self.blocks().all(|w| w == 0)
625 /// Returns `true` if any bit is 1.
630 /// use std::collections::Bitv;
632 /// let mut bv = Bitv::from_elem(10, false);
633 /// assert_eq!(bv.any(), false);
636 /// assert_eq!(bv.any(), true);
639 pub fn any(&self) -> bool {
643 /// Organises the bits into bytes, such that the first bit in the
644 /// `Bitv` becomes the high-order bit of the first byte. If the
645 /// size of the `Bitv` is not a multiple of eight then trailing bits
646 /// will be filled-in with `false`.
651 /// use std::collections::Bitv;
653 /// let mut bv = Bitv::from_elem(3, true);
654 /// bv.set(1, false);
656 /// assert_eq!(bv.to_bytes(), vec!(0b10100000));
658 /// let mut bv = Bitv::from_elem(9, false);
662 /// assert_eq!(bv.to_bytes(), vec!(0b00100000, 0b10000000));
664 pub fn to_bytes(&self) -> Vec<u8> {
665 fn bit(bitv: &Bitv, byte: uint, bit: uint) -> u8 {
666 let offset = byte * 8 + bit;
667 if offset >= bitv.nbits {
670 (bitv[offset] as u8) << (7 - bit)
674 let len = self.nbits/8 +
675 if self.nbits % 8 == 0 { 0 } else { 1 };
676 range(0, len).map(|i|
688 /// Deprecated: Use `iter().collect()`.
689 #[deprecated = "Use `iter().collect()`"]
690 pub fn to_bools(&self) -> Vec<bool> {
691 self.iter().collect()
694 /// Compares a `Bitv` to a slice of `bool`s.
695 /// Both the `Bitv` and slice must have the same length.
699 /// Panics if the `Bitv` and slice are of different length.
704 /// use std::collections::Bitv;
706 /// let bv = Bitv::from_bytes(&[0b10100000]);
708 /// assert!(bv.eq_vec(&[true, false, true, false,
709 /// false, false, false, false]));
711 pub fn eq_vec(&self, v: &[bool]) -> bool {
712 assert_eq!(self.nbits, v.len());
713 iter::order::eq(self.iter(), v.iter().cloned())
716 /// Shortens a `Bitv`, dropping excess elements.
718 /// If `len` is greater than the vector's current length, this has no
724 /// use std::collections::Bitv;
726 /// let mut bv = Bitv::from_bytes(&[0b01001011]);
728 /// assert!(bv.eq_vec(&[false, true]));
731 pub fn truncate(&mut self, len: uint) {
732 if len < self.len() {
735 self.storage.truncate(blocks_for_bits(len));
736 self.fix_last_block();
740 /// Reserves capacity for at least `additional` more bits to be inserted in the given
741 /// `Bitv`. The collection may reserve more space to avoid frequent reallocations.
745 /// Panics if the new capacity overflows `uint`.
750 /// use std::collections::Bitv;
752 /// let mut bv = Bitv::from_elem(3, false);
754 /// assert_eq!(bv.len(), 3);
755 /// assert!(bv.capacity() >= 13);
758 pub fn reserve(&mut self, additional: uint) {
759 let desired_cap = self.len().checked_add(additional).expect("capacity overflow");
760 let storage_len = self.storage.len();
761 if desired_cap > self.capacity() {
762 self.storage.reserve(blocks_for_bits(desired_cap) - storage_len);
766 /// Reserves the minimum capacity for exactly `additional` more bits to be inserted in the
767 /// given `Bitv`. Does nothing if the capacity is already sufficient.
769 /// Note that the allocator may give the collection more space than it requests. Therefore
770 /// capacity can not be relied upon to be precisely minimal. Prefer `reserve` if future
771 /// insertions are expected.
775 /// Panics if the new capacity overflows `uint`.
780 /// use std::collections::Bitv;
782 /// let mut bv = Bitv::from_elem(3, false);
784 /// assert_eq!(bv.len(), 3);
785 /// assert!(bv.capacity() >= 13);
788 pub fn reserve_exact(&mut self, additional: uint) {
789 let desired_cap = self.len().checked_add(additional).expect("capacity overflow");
790 let storage_len = self.storage.len();
791 if desired_cap > self.capacity() {
792 self.storage.reserve_exact(blocks_for_bits(desired_cap) - storage_len);
796 /// Returns the capacity in bits for this bit vector. Inserting any
797 /// element less than this amount will not trigger a resizing.
802 /// use std::collections::Bitv;
804 /// let mut bv = Bitv::new();
806 /// assert!(bv.capacity() >= 10);
810 pub fn capacity(&self) -> uint {
811 self.storage.capacity().checked_mul(u32::BITS).unwrap_or(uint::MAX)
814 /// Grows the `Bitv` in-place, adding `n` copies of `value` to the `Bitv`.
818 /// Panics if the new len overflows a `uint`.
823 /// use std::collections::Bitv;
825 /// let mut bv = Bitv::from_bytes(&[0b01001011]);
826 /// bv.grow(2, true);
827 /// assert_eq!(bv.len(), 10);
828 /// assert_eq!(bv.to_bytes(), vec!(0b01001011, 0b11000000));
830 pub fn grow(&mut self, n: uint, value: bool) {
831 // Note: we just bulk set all the bits in the last word in this fn in multiple places
832 // which is technically wrong if not all of these bits are to be used. However, at the end
833 // of this fn we call `fix_last_block` at the end of this fn, which should fix this.
835 let new_nbits = self.nbits.checked_add(n).expect("capacity overflow");
836 let new_nblocks = blocks_for_bits(new_nbits);
837 let full_value = if value { !0 } else { 0 };
839 // Correct the old tail word, setting or clearing formerly unused bits
840 let old_last_word = blocks_for_bits(self.nbits) - 1;
841 if self.nbits % u32::BITS > 0 {
842 let mask = mask_for_bits(self.nbits);
844 self.storage[old_last_word] |= !mask;
846 // Extra bits are already zero by invariant.
850 // Fill in words after the old tail word
851 let stop_idx = cmp::min(self.storage.len(), new_nblocks);
852 for idx in range(old_last_word + 1, stop_idx) {
853 self.storage[idx] = full_value;
856 // Allocate new words, if needed
857 if new_nblocks > self.storage.len() {
858 let to_add = new_nblocks - self.storage.len();
859 self.storage.extend(repeat(full_value).take(to_add));
862 // Adjust internal bit count
863 self.nbits = new_nbits;
865 self.fix_last_block();
868 /// Removes the last bit from the Bitv, and returns it. Returns None if the Bitv is empty.
873 /// use std::collections::Bitv;
875 /// let mut bv = Bitv::from_bytes(&[0b01001001]);
876 /// assert_eq!(bv.pop(), Some(true));
877 /// assert_eq!(bv.pop(), Some(false));
878 /// assert_eq!(bv.len(), 6);
881 pub fn pop(&mut self) -> Option<bool> {
885 let i = self.nbits - 1;
890 if self.nbits % u32::BITS == 0 {
898 /// Pushes a `bool` onto the end.
903 /// use std::collections::Bitv;
905 /// let mut bv = Bitv::new();
908 /// assert!(bv.eq_vec(&[true, false]));
911 pub fn push(&mut self, elem: bool) {
912 if self.nbits % u32::BITS == 0 {
913 self.storage.push(0);
915 let insert_pos = self.nbits;
916 self.nbits = self.nbits.checked_add(1).expect("Capacity overflow");
917 self.set(insert_pos, elem);
920 /// Return the total number of bits in this vector
923 pub fn len(&self) -> uint { self.nbits }
925 /// Returns true if there are no bits in this vector
928 pub fn is_empty(&self) -> bool { self.len() == 0 }
930 /// Clears all bits in this vector.
933 pub fn clear(&mut self) {
934 for w in self.storage.iter_mut() { *w = 0u32; }
938 /// Deprecated: Now a static method on Bitv.
939 #[deprecated = "Now a static method on Bitv"]
940 pub fn from_bytes(bytes: &[u8]) -> Bitv {
941 Bitv::from_bytes(bytes)
944 /// Deprecated: Now a static method on Bitv.
945 #[deprecated = "Now a static method on Bitv"]
946 pub fn from_fn<F>(len: uint, f: F) -> Bitv where F: FnMut(uint) -> bool {
947 Bitv::from_fn(len, f)
951 impl Default for Bitv {
953 fn default() -> Bitv { Bitv::new() }
957 impl FromIterator<bool> for Bitv {
958 fn from_iter<I:Iterator<Item=bool>>(iterator: I) -> Bitv {
959 let mut ret = Bitv::new();
960 ret.extend(iterator);
966 impl Extend<bool> for Bitv {
968 fn extend<I: Iterator<Item=bool>>(&mut self, mut iterator: I) {
969 let (min, _) = iterator.size_hint();
971 for element in iterator {
978 impl Clone for Bitv {
980 fn clone(&self) -> Bitv {
981 Bitv { storage: self.storage.clone(), nbits: self.nbits }
985 fn clone_from(&mut self, source: &Bitv) {
986 self.nbits = source.nbits;
987 self.storage.clone_from(&source.storage);
992 impl PartialOrd for Bitv {
994 fn partial_cmp(&self, other: &Bitv) -> Option<Ordering> {
995 iter::order::partial_cmp(self.iter(), other.iter())
1002 fn cmp(&self, other: &Bitv) -> Ordering {
1003 iter::order::cmp(self.iter(), other.iter())
1008 impl fmt::Show for Bitv {
1009 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
1010 for bit in self.iter() {
1011 try!(write!(fmt, "{}", if bit { 1u32 } else { 0u32 }));
1018 impl<S: hash::Writer> hash::Hash<S> for Bitv {
1019 fn hash(&self, state: &mut S) {
1020 self.nbits.hash(state);
1021 for elem in self.blocks() {
1028 impl cmp::PartialEq for Bitv {
1030 fn eq(&self, other: &Bitv) -> bool {
1031 if self.nbits != other.nbits {
1034 self.blocks().zip(other.blocks()).all(|(w1, w2)| w1 == w2)
1039 impl cmp::Eq for Bitv {}
1041 /// An iterator for `Bitv`.
1044 pub struct Iter<'a> {
1051 impl<'a> Iterator for Iter<'a> {
1055 fn next(&mut self) -> Option<bool> {
1056 if self.next_idx != self.end_idx {
1057 let idx = self.next_idx;
1059 Some(self.bitv[idx])
1065 fn size_hint(&self) -> (uint, Option<uint>) {
1066 let rem = self.end_idx - self.next_idx;
1072 impl<'a> DoubleEndedIterator for Iter<'a> {
1074 fn next_back(&mut self) -> Option<bool> {
1075 if self.next_idx != self.end_idx {
1077 Some(self.bitv[self.end_idx])
1085 impl<'a> ExactSizeIterator for Iter<'a> {}
1088 impl<'a> RandomAccessIterator for Iter<'a> {
1090 fn indexable(&self) -> uint {
1091 self.end_idx - self.next_idx
1095 fn idx(&mut self, index: uint) -> Option<bool> {
1096 if index >= self.indexable() {
1099 Some(self.bitv[index])
1104 /// An implementation of a set using a bit vector as an underlying
1105 /// representation for holding unsigned numerical elements.
1107 /// It should also be noted that the amount of storage necessary for holding a
1108 /// set of objects is proportional to the maximum of the objects when viewed
1114 /// use std::collections::{BitvSet, Bitv};
1116 /// // It's a regular set
1117 /// let mut s = BitvSet::new();
1124 /// if !s.contains(&7) {
1125 /// println!("There is no 7");
1128 /// // Can initialize from a `Bitv`
1129 /// let other = BitvSet::from_bitv(Bitv::from_bytes(&[0b11010000]));
1131 /// s.union_with(&other);
1133 /// // Print 0, 1, 3 in some order
1134 /// for x in s.iter() {
1135 /// println!("{}", x);
1138 /// // Can convert back to a `Bitv`
1139 /// let bv: Bitv = s.into_bitv();
1144 pub struct BitvSet {
1149 impl Default for BitvSet {
1151 fn default() -> BitvSet { BitvSet::new() }
1155 impl FromIterator<uint> for BitvSet {
1156 fn from_iter<I:Iterator<Item=uint>>(iterator: I) -> BitvSet {
1157 let mut ret = BitvSet::new();
1158 ret.extend(iterator);
1164 impl Extend<uint> for BitvSet {
1166 fn extend<I: Iterator<Item=uint>>(&mut self, mut iterator: I) {
1174 impl PartialOrd for BitvSet {
1176 fn partial_cmp(&self, other: &BitvSet) -> Option<Ordering> {
1177 let (a_iter, b_iter) = match_words(self.get_ref(), other.get_ref());
1178 iter::order::partial_cmp(a_iter, b_iter)
1183 impl Ord for BitvSet {
1185 fn cmp(&self, other: &BitvSet) -> Ordering {
1186 let (a_iter, b_iter) = match_words(self.get_ref(), other.get_ref());
1187 iter::order::cmp(a_iter, b_iter)
1192 impl cmp::PartialEq for BitvSet {
1194 fn eq(&self, other: &BitvSet) -> bool {
1195 let (a_iter, b_iter) = match_words(self.get_ref(), other.get_ref());
1196 iter::order::eq(a_iter, b_iter)
1201 impl cmp::Eq for BitvSet {}
1204 /// Creates a new empty `BitvSet`.
1209 /// use std::collections::BitvSet;
1211 /// let mut s = BitvSet::new();
1215 pub fn new() -> BitvSet {
1216 BitvSet { bitv: Bitv::new() }
1219 /// Creates a new `BitvSet` with initially no contents, able to
1220 /// hold `nbits` elements without resizing.
1225 /// use std::collections::BitvSet;
1227 /// let mut s = BitvSet::with_capacity(100);
1228 /// assert!(s.capacity() >= 100);
1232 pub fn with_capacity(nbits: uint) -> BitvSet {
1233 let bitv = Bitv::from_elem(nbits, false);
1234 BitvSet::from_bitv(bitv)
1237 /// Creates a new `BitvSet` from the given bit vector.
1242 /// use std::collections::{Bitv, BitvSet};
1244 /// let bv = Bitv::from_bytes(&[0b01100000]);
1245 /// let s = BitvSet::from_bitv(bv);
1247 /// // Print 1, 2 in arbitrary order
1248 /// for x in s.iter() {
1249 /// println!("{}", x);
1253 pub fn from_bitv(bitv: Bitv) -> BitvSet {
1254 BitvSet { bitv: bitv }
1257 /// Returns the capacity in bits for this bit vector. Inserting any
1258 /// element less than this amount will not trigger a resizing.
1263 /// use std::collections::BitvSet;
1265 /// let mut s = BitvSet::with_capacity(100);
1266 /// assert!(s.capacity() >= 100);
1270 pub fn capacity(&self) -> uint {
1271 self.bitv.capacity()
1274 /// Reserves capacity for the given `BitvSet` to contain `len` distinct elements. In the case
1275 /// of `BitvSet` this means reallocations will not occur as long as all inserted elements
1276 /// are less than `len`.
1278 /// The collection may reserve more space to avoid frequent reallocations.
1284 /// use std::collections::BitvSet;
1286 /// let mut s = BitvSet::new();
1287 /// s.reserve_len(10);
1288 /// assert!(s.capacity() >= 10);
1291 pub fn reserve_len(&mut self, len: uint) {
1292 let cur_len = self.bitv.len();
1294 self.bitv.reserve(len - cur_len);
1298 /// Reserves the minimum capacity for the given `BitvSet` to contain `len` distinct elements.
1299 /// In the case of `BitvSet` this means reallocations will not occur as long as all inserted
1300 /// elements are less than `len`.
1302 /// Note that the allocator may give the collection more space than it requests. Therefore
1303 /// capacity can not be relied upon to be precisely minimal. Prefer `reserve_len` if future
1304 /// insertions are expected.
1310 /// use std::collections::BitvSet;
1312 /// let mut s = BitvSet::new();
1313 /// s.reserve_len_exact(10);
1314 /// assert!(s.capacity() >= 10);
1317 pub fn reserve_len_exact(&mut self, len: uint) {
1318 let cur_len = self.bitv.len();
1320 self.bitv.reserve_exact(len - cur_len);
1325 /// Consumes this set to return the underlying bit vector.
1330 /// use std::collections::BitvSet;
1332 /// let mut s = BitvSet::new();
1336 /// let bv = s.into_bitv();
1341 pub fn into_bitv(self) -> Bitv {
1345 /// Returns a reference to the underlying bit vector.
1350 /// use std::collections::BitvSet;
1352 /// let mut s = BitvSet::new();
1355 /// let bv = s.get_ref();
1356 /// assert_eq!(bv[0], true);
1359 pub fn get_ref(&self) -> &Bitv {
1364 fn other_op<F>(&mut self, other: &BitvSet, mut f: F) where F: FnMut(u32, u32) -> u32 {
1366 let self_bitv = &mut self.bitv;
1367 let other_bitv = &other.bitv;
1369 let self_len = self_bitv.len();
1370 let other_len = other_bitv.len();
1372 // Expand the vector if necessary
1373 if self_len < other_len {
1374 self_bitv.grow(other_len - self_len, false);
1377 // virtually pad other with 0's for equal lengths
1378 let mut other_words = {
1379 let (_, result) = match_words(self_bitv, other_bitv);
1383 // Apply values found in other
1384 for (i, w) in other_words {
1385 let old = self_bitv.storage[i];
1386 let new = f(old, w);
1387 self_bitv.storage[i] = new;
1391 /// Truncates the underlying vector to the least length required.
1396 /// use std::collections::BitvSet;
1398 /// let mut s = BitvSet::new();
1399 /// s.insert(32183231);
1400 /// s.remove(&32183231);
1402 /// // Internal storage will probably be bigger than necessary
1403 /// println!("old capacity: {}", s.capacity());
1405 /// // Now should be smaller
1406 /// s.shrink_to_fit();
1407 /// println!("new capacity: {}", s.capacity());
1411 pub fn shrink_to_fit(&mut self) {
1412 let bitv = &mut self.bitv;
1413 // Obtain original length
1414 let old_len = bitv.storage.len();
1415 // Obtain coarse trailing zero length
1416 let n = bitv.storage.iter().rev().take_while(|&&n| n == 0).count();
1418 let trunc_len = cmp::max(old_len - n, 1);
1419 bitv.storage.truncate(trunc_len);
1420 bitv.nbits = trunc_len * u32::BITS;
1423 /// Iterator over each u32 stored in the `BitvSet`.
1428 /// use std::collections::{Bitv, BitvSet};
1430 /// let s = BitvSet::from_bitv(Bitv::from_bytes(&[0b01001010]));
1432 /// // Print 1, 4, 6 in arbitrary order
1433 /// for x in s.iter() {
1434 /// println!("{}", x);
1439 pub fn iter(&self) -> bitv_set::Iter {
1440 SetIter {set: self, next_idx: 0u}
1443 /// Iterator over each u32 stored in `self` union `other`.
1444 /// See [union_with](#method.union_with) for an efficient in-place version.
1449 /// use std::collections::{Bitv, BitvSet};
1451 /// let a = BitvSet::from_bitv(Bitv::from_bytes(&[0b01101000]));
1452 /// let b = BitvSet::from_bitv(Bitv::from_bytes(&[0b10100000]));
1454 /// // Print 0, 1, 2, 4 in arbitrary order
1455 /// for x in a.union(&b) {
1456 /// println!("{}", x);
1461 pub fn union<'a>(&'a self, other: &'a BitvSet) -> Union<'a> {
1462 fn or(w1: u32, w2: u32) -> u32 { w1 | w2 }
1464 Union(TwoBitPositions {
1473 /// Iterator over each uint stored in `self` intersect `other`.
1474 /// See [intersect_with](#method.intersect_with) for an efficient in-place version.
1479 /// use std::collections::{Bitv, BitvSet};
1481 /// let a = BitvSet::from_bitv(Bitv::from_bytes(&[0b01101000]));
1482 /// let b = BitvSet::from_bitv(Bitv::from_bytes(&[0b10100000]));
1485 /// for x in a.intersection(&b) {
1486 /// println!("{}", x);
1491 pub fn intersection<'a>(&'a self, other: &'a BitvSet) -> Intersection<'a> {
1492 fn bitand(w1: u32, w2: u32) -> u32 { w1 & w2 }
1493 let min = cmp::min(self.bitv.len(), other.bitv.len());
1494 Intersection(TwoBitPositions {
1503 /// Iterator over each uint stored in the `self` setminus `other`.
1504 /// See [difference_with](#method.difference_with) for an efficient in-place version.
1509 /// use std::collections::{BitvSet, Bitv};
1511 /// let a = BitvSet::from_bitv(Bitv::from_bytes(&[0b01101000]));
1512 /// let b = BitvSet::from_bitv(Bitv::from_bytes(&[0b10100000]));
1514 /// // Print 1, 4 in arbitrary order
1515 /// for x in a.difference(&b) {
1516 /// println!("{}", x);
1519 /// // Note that difference is not symmetric,
1520 /// // and `b - a` means something else.
1521 /// // This prints 0
1522 /// for x in b.difference(&a) {
1523 /// println!("{}", x);
1528 pub fn difference<'a>(&'a self, other: &'a BitvSet) -> Difference<'a> {
1529 fn diff(w1: u32, w2: u32) -> u32 { w1 & !w2 }
1531 Difference(TwoBitPositions {
1540 /// Iterator over each u32 stored in the symmetric difference of `self` and `other`.
1541 /// See [symmetric_difference_with](#method.symmetric_difference_with) for
1542 /// an efficient in-place version.
1547 /// use std::collections::{BitvSet, Bitv};
1549 /// let a = BitvSet::from_bitv(Bitv::from_bytes(&[0b01101000]));
1550 /// let b = BitvSet::from_bitv(Bitv::from_bytes(&[0b10100000]));
1552 /// // Print 0, 1, 4 in arbitrary order
1553 /// for x in a.symmetric_difference(&b) {
1554 /// println!("{}", x);
1559 pub fn symmetric_difference<'a>(&'a self, other: &'a BitvSet) -> SymmetricDifference<'a> {
1560 fn bitxor(w1: u32, w2: u32) -> u32 { w1 ^ w2 }
1562 SymmetricDifference(TwoBitPositions {
1571 /// Unions in-place with the specified other bit vector.
1576 /// use std::collections::{BitvSet, Bitv};
1578 /// let a = 0b01101000;
1579 /// let b = 0b10100000;
1580 /// let res = 0b11101000;
1582 /// let mut a = BitvSet::from_bitv(Bitv::from_bytes(&[a]));
1583 /// let b = BitvSet::from_bitv(Bitv::from_bytes(&[b]));
1584 /// let res = BitvSet::from_bitv(Bitv::from_bytes(&[res]));
1586 /// a.union_with(&b);
1587 /// assert_eq!(a, res);
1590 pub fn union_with(&mut self, other: &BitvSet) {
1591 self.other_op(other, |w1, w2| w1 | w2);
1594 /// Intersects in-place with the specified other bit vector.
1599 /// use std::collections::{BitvSet, Bitv};
1601 /// let a = 0b01101000;
1602 /// let b = 0b10100000;
1603 /// let res = 0b00100000;
1605 /// let mut a = BitvSet::from_bitv(Bitv::from_bytes(&[a]));
1606 /// let b = BitvSet::from_bitv(Bitv::from_bytes(&[b]));
1607 /// let res = BitvSet::from_bitv(Bitv::from_bytes(&[res]));
1609 /// a.intersect_with(&b);
1610 /// assert_eq!(a, res);
1613 pub fn intersect_with(&mut self, other: &BitvSet) {
1614 self.other_op(other, |w1, w2| w1 & w2);
1617 /// Makes this bit vector the difference with the specified other bit vector
1623 /// use std::collections::{BitvSet, Bitv};
1625 /// let a = 0b01101000;
1626 /// let b = 0b10100000;
1627 /// let a_b = 0b01001000; // a - b
1628 /// let b_a = 0b10000000; // b - a
1630 /// let mut bva = BitvSet::from_bitv(Bitv::from_bytes(&[a]));
1631 /// let bvb = BitvSet::from_bitv(Bitv::from_bytes(&[b]));
1632 /// let bva_b = BitvSet::from_bitv(Bitv::from_bytes(&[a_b]));
1633 /// let bvb_a = BitvSet::from_bitv(Bitv::from_bytes(&[b_a]));
1635 /// bva.difference_with(&bvb);
1636 /// assert_eq!(bva, bva_b);
1638 /// let bva = BitvSet::from_bitv(Bitv::from_bytes(&[a]));
1639 /// let mut bvb = BitvSet::from_bitv(Bitv::from_bytes(&[b]));
1641 /// bvb.difference_with(&bva);
1642 /// assert_eq!(bvb, bvb_a);
1645 pub fn difference_with(&mut self, other: &BitvSet) {
1646 self.other_op(other, |w1, w2| w1 & !w2);
1649 /// Makes this bit vector the symmetric difference with the specified other
1650 /// bit vector in-place.
1655 /// use std::collections::{BitvSet, Bitv};
1657 /// let a = 0b01101000;
1658 /// let b = 0b10100000;
1659 /// let res = 0b11001000;
1661 /// let mut a = BitvSet::from_bitv(Bitv::from_bytes(&[a]));
1662 /// let b = BitvSet::from_bitv(Bitv::from_bytes(&[b]));
1663 /// let res = BitvSet::from_bitv(Bitv::from_bytes(&[res]));
1665 /// a.symmetric_difference_with(&b);
1666 /// assert_eq!(a, res);
1669 pub fn symmetric_difference_with(&mut self, other: &BitvSet) {
1670 self.other_op(other, |w1, w2| w1 ^ w2);
1673 /// Return the number of set bits in this set.
1676 pub fn len(&self) -> uint {
1677 self.bitv.blocks().fold(0, |acc, n| acc + n.count_ones())
1680 /// Returns whether there are no bits set in this set
1683 pub fn is_empty(&self) -> bool {
1687 /// Clears all bits in this set
1690 pub fn clear(&mut self) {
1694 /// Returns `true` if this set contains the specified integer.
1697 pub fn contains(&self, value: &uint) -> bool {
1698 let bitv = &self.bitv;
1699 *value < bitv.nbits && bitv[*value]
1702 /// Returns `true` if the set has no elements in common with `other`.
1703 /// This is equivalent to checking for an empty intersection.
1706 pub fn is_disjoint(&self, other: &BitvSet) -> bool {
1707 self.intersection(other).next().is_none()
1710 /// Returns `true` if the set is a subset of another.
1713 pub fn is_subset(&self, other: &BitvSet) -> bool {
1714 let self_bitv = &self.bitv;
1715 let other_bitv = &other.bitv;
1716 let other_blocks = blocks_for_bits(other_bitv.len());
1718 // Check that `self` intersect `other` is self
1719 self_bitv.blocks().zip(other_bitv.blocks()).all(|(w1, w2)| w1 & w2 == w1) &&
1720 // Make sure if `self` has any more blocks than `other`, they're all 0
1721 self_bitv.blocks().skip(other_blocks).all(|w| w == 0)
1724 /// Returns `true` if the set is a superset of another.
1727 pub fn is_superset(&self, other: &BitvSet) -> bool {
1728 other.is_subset(self)
1731 /// Adds a value to the set. Returns `true` if the value was not already
1732 /// present in the set.
1734 pub fn insert(&mut self, value: uint) -> bool {
1735 if self.contains(&value) {
1739 // Ensure we have enough space to hold the new element
1740 let len = self.bitv.len();
1742 self.bitv.grow(value - len + 1, false)
1745 self.bitv.set(value, true);
1749 /// Removes a value from the set. Returns `true` if the value was
1750 /// present in the set.
1752 pub fn remove(&mut self, value: &uint) -> bool {
1753 if !self.contains(value) {
1757 self.bitv.set(*value, false);
1763 impl fmt::Show for BitvSet {
1764 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
1765 try!(write!(fmt, "{{"));
1766 let mut first = true;
1767 for n in self.iter() {
1769 try!(write!(fmt, ", "));
1771 try!(write!(fmt, "{}", n));
1778 impl<S: hash::Writer> hash::Hash<S> for BitvSet {
1779 fn hash(&self, state: &mut S) {
1780 for pos in self.iter() {
1786 /// An iterator for `BitvSet`.
1789 pub struct SetIter<'a> {
1794 /// An iterator combining two `BitvSet` iterators.
1796 struct TwoBitPositions<'a> {
1799 merge: fn(u32, u32) -> u32,
1805 pub struct Union<'a>(TwoBitPositions<'a>);
1807 pub struct Intersection<'a>(Take<TwoBitPositions<'a>>);
1809 pub struct Difference<'a>(TwoBitPositions<'a>);
1811 pub struct SymmetricDifference<'a>(TwoBitPositions<'a>);
1814 impl<'a> Iterator for SetIter<'a> {
1817 fn next(&mut self) -> Option<uint> {
1818 while self.next_idx < self.set.bitv.len() {
1819 let idx = self.next_idx;
1822 if self.set.contains(&idx) {
1831 fn size_hint(&self) -> (uint, Option<uint>) {
1832 (0, Some(self.set.bitv.len() - self.next_idx))
1837 impl<'a> Iterator for TwoBitPositions<'a> {
1840 fn next(&mut self) -> Option<uint> {
1841 while self.next_idx < self.set.bitv.len() ||
1842 self.next_idx < self.other.bitv.len() {
1843 let bit_idx = self.next_idx % u32::BITS;
1845 let s_bitv = &self.set.bitv;
1846 let o_bitv = &self.other.bitv;
1847 // Merging the two words is a bit of an awkward dance since
1848 // one Bitv might be longer than the other
1849 let word_idx = self.next_idx / u32::BITS;
1850 let w1 = if word_idx < s_bitv.storage.len() {
1851 s_bitv.storage[word_idx]
1853 let w2 = if word_idx < o_bitv.storage.len() {
1854 o_bitv.storage[word_idx]
1856 self.current_word = (self.merge)(w1, w2);
1860 if self.current_word & (1 << bit_idx) != 0 {
1861 return Some(self.next_idx - 1);
1868 fn size_hint(&self) -> (uint, Option<uint>) {
1869 let cap = cmp::max(self.set.bitv.len(), self.other.bitv.len());
1870 (0, Some(cap - self.next_idx))
1875 impl<'a> Iterator for Union<'a> {
1878 #[inline] fn next(&mut self) -> Option<uint> { self.0.next() }
1879 #[inline] fn size_hint(&self) -> (uint, Option<uint>) { self.0.size_hint() }
1883 impl<'a> Iterator for Intersection<'a> {
1886 #[inline] fn next(&mut self) -> Option<uint> { self.0.next() }
1887 #[inline] fn size_hint(&self) -> (uint, Option<uint>) { self.0.size_hint() }
1891 impl<'a> Iterator for Difference<'a> {
1894 #[inline] fn next(&mut self) -> Option<uint> { self.0.next() }
1895 #[inline] fn size_hint(&self) -> (uint, Option<uint>) { self.0.size_hint() }
1899 impl<'a> Iterator for SymmetricDifference<'a> {
1902 #[inline] fn next(&mut self) -> Option<uint> { self.0.next() }
1903 #[inline] fn size_hint(&self) -> (uint, Option<uint>) { self.0.size_hint() }
1910 use core::iter::range_step;
1914 use test::{Bencher, black_box};
1916 use super::{Bitv, BitvSet, from_fn, from_bytes};
1921 let zerolen = Bitv::new();
1922 assert_eq!(zerolen.to_string(), "");
1924 let eightbits = Bitv::from_elem(8u, false);
1925 assert_eq!(eightbits.to_string(), "00000000")
1929 fn test_0_elements() {
1930 let act = Bitv::new();
1931 let exp = Vec::from_elem(0u, false);
1932 assert!(act.eq_vec(exp.as_slice()));
1933 assert!(act.none() && act.all());
1937 fn test_1_element() {
1938 let mut act = Bitv::from_elem(1u, false);
1939 assert!(act.eq_vec(&[false]));
1940 assert!(act.none() && !act.all());
1941 act = Bitv::from_elem(1u, true);
1942 assert!(act.eq_vec(&[true]));
1943 assert!(!act.none() && act.all());
1947 fn test_2_elements() {
1948 let mut b = Bitv::from_elem(2, false);
1951 assert_eq!(b.to_string(), "10");
1952 assert!(!b.none() && !b.all());
1956 fn test_10_elements() {
1960 act = Bitv::from_elem(10u, false);
1961 assert!((act.eq_vec(
1962 &[false, false, false, false, false, false, false, false, false, false])));
1963 assert!(act.none() && !act.all());
1966 act = Bitv::from_elem(10u, true);
1967 assert!((act.eq_vec(&[true, true, true, true, true, true, true, true, true, true])));
1968 assert!(!act.none() && act.all());
1971 act = Bitv::from_elem(10u, false);
1977 assert!((act.eq_vec(&[true, true, true, true, true, false, false, false, false, false])));
1978 assert!(!act.none() && !act.all());
1981 act = Bitv::from_elem(10u, false);
1987 assert!((act.eq_vec(&[false, false, false, false, false, true, true, true, true, true])));
1988 assert!(!act.none() && !act.all());
1991 act = Bitv::from_elem(10u, false);
1996 assert!((act.eq_vec(&[true, false, false, true, false, false, true, false, false, true])));
1997 assert!(!act.none() && !act.all());
2001 fn test_31_elements() {
2005 act = Bitv::from_elem(31u, false);
2007 &[false, false, false, false, false, false, false, false, false, false, false,
2008 false, false, false, false, false, false, false, false, false, false, false,
2009 false, false, false, false, false, false, false, false, false]));
2010 assert!(act.none() && !act.all());
2013 act = Bitv::from_elem(31u, true);
2015 &[true, true, true, true, true, true, true, true, true, true, true, true, true,
2016 true, true, true, true, true, true, true, true, true, true, true, true, true,
2017 true, true, true, true, true]));
2018 assert!(!act.none() && act.all());
2021 act = Bitv::from_elem(31u, false);
2031 &[true, true, true, true, true, true, true, true, false, false, false, false, false,
2032 false, false, false, false, false, false, false, false, false, false, false,
2033 false, false, false, false, false, false, false]));
2034 assert!(!act.none() && !act.all());
2037 act = Bitv::from_elem(31u, false);
2047 &[false, false, false, false, false, false, false, false, false, false, false,
2048 false, false, false, false, false, true, true, true, true, true, true, true, true,
2049 false, false, false, false, false, false, false]));
2050 assert!(!act.none() && !act.all());
2053 act = Bitv::from_elem(31u, false);
2062 &[false, false, false, false, false, false, false, false, false, false, false,
2063 false, false, false, false, false, false, false, false, false, false, false,
2064 false, false, true, true, true, true, true, true, true]));
2065 assert!(!act.none() && !act.all());
2068 act = Bitv::from_elem(31u, false);
2073 &[false, false, false, true, false, false, false, false, false, false, false, false,
2074 false, false, false, false, false, true, false, false, false, false, false, false,
2075 false, false, false, false, false, false, true]));
2076 assert!(!act.none() && !act.all());
2080 fn test_32_elements() {
2084 act = Bitv::from_elem(32u, false);
2086 &[false, false, false, false, false, false, false, false, false, false, false,
2087 false, false, false, false, false, false, false, false, false, false, false,
2088 false, false, false, false, false, false, false, false, false, false]));
2089 assert!(act.none() && !act.all());
2092 act = Bitv::from_elem(32u, true);
2094 &[true, true, true, true, true, true, true, true, true, true, true, true, true,
2095 true, true, true, true, true, true, true, true, true, true, true, true, true,
2096 true, true, true, true, true, true]));
2097 assert!(!act.none() && act.all());
2100 act = Bitv::from_elem(32u, false);
2110 &[true, true, true, true, true, true, true, true, false, false, false, false, false,
2111 false, false, false, false, false, false, false, false, false, false, false,
2112 false, false, false, false, false, false, false, false]));
2113 assert!(!act.none() && !act.all());
2116 act = Bitv::from_elem(32u, false);
2126 &[false, false, false, false, false, false, false, false, false, false, false,
2127 false, false, false, false, false, true, true, true, true, true, true, true, true,
2128 false, false, false, false, false, false, false, false]));
2129 assert!(!act.none() && !act.all());
2132 act = Bitv::from_elem(32u, false);
2142 &[false, false, false, false, false, false, false, false, false, false, false,
2143 false, false, false, false, false, false, false, false, false, false, false,
2144 false, false, true, true, true, true, true, true, true, true]));
2145 assert!(!act.none() && !act.all());
2148 act = Bitv::from_elem(32u, false);
2154 &[false, false, false, true, false, false, false, false, false, false, false, false,
2155 false, false, false, false, false, true, false, false, false, false, false, false,
2156 false, false, false, false, false, false, true, true]));
2157 assert!(!act.none() && !act.all());
2161 fn test_33_elements() {
2165 act = Bitv::from_elem(33u, false);
2167 &[false, false, false, false, false, false, false, false, false, false, false,
2168 false, false, false, false, false, false, false, false, false, false, false,
2169 false, false, false, false, false, false, false, false, false, false, false]));
2170 assert!(act.none() && !act.all());
2173 act = Bitv::from_elem(33u, true);
2175 &[true, true, true, true, true, true, true, true, true, true, true, true, true,
2176 true, true, true, true, true, true, true, true, true, true, true, true, true,
2177 true, true, true, true, true, true, true]));
2178 assert!(!act.none() && act.all());
2181 act = Bitv::from_elem(33u, false);
2191 &[true, true, true, true, true, true, true, true, false, false, false, false, false,
2192 false, false, false, false, false, false, false, false, false, false, false,
2193 false, false, false, false, false, false, false, false, false]));
2194 assert!(!act.none() && !act.all());
2197 act = Bitv::from_elem(33u, false);
2207 &[false, false, false, false, false, false, false, false, false, false, false,
2208 false, false, false, false, false, true, true, true, true, true, true, true, true,
2209 false, false, false, false, false, false, false, false, false]));
2210 assert!(!act.none() && !act.all());
2213 act = Bitv::from_elem(33u, false);
2223 &[false, false, false, false, false, false, false, false, false, false, false,
2224 false, false, false, false, false, false, false, false, false, false, false,
2225 false, false, true, true, true, true, true, true, true, true, false]));
2226 assert!(!act.none() && !act.all());
2229 act = Bitv::from_elem(33u, false);
2236 &[false, false, false, true, false, false, false, false, false, false, false, false,
2237 false, false, false, false, false, true, false, false, false, false, false, false,
2238 false, false, false, false, false, false, true, true, true]));
2239 assert!(!act.none() && !act.all());
2243 fn test_equal_differing_sizes() {
2244 let v0 = Bitv::from_elem(10u, false);
2245 let v1 = Bitv::from_elem(11u, false);
2250 fn test_equal_greatly_differing_sizes() {
2251 let v0 = Bitv::from_elem(10u, false);
2252 let v1 = Bitv::from_elem(110u, false);
2257 fn test_equal_sneaky_small() {
2258 let mut a = Bitv::from_elem(1, false);
2261 let mut b = Bitv::from_elem(1, true);
2268 fn test_equal_sneaky_big() {
2269 let mut a = Bitv::from_elem(100, false);
2270 for i in range(0u, 100) {
2274 let mut b = Bitv::from_elem(100, true);
2275 for i in range(0u, 100) {
2283 fn test_from_bytes() {
2284 let bitv = Bitv::from_bytes(&[0b10110110, 0b00000000, 0b11111111]);
2285 let str = concat!("10110110", "00000000", "11111111");
2286 assert_eq!(bitv.to_string(), str);
2290 fn test_to_bytes() {
2291 let mut bv = Bitv::from_elem(3, true);
2293 assert_eq!(bv.to_bytes(), vec!(0b10100000));
2295 let mut bv = Bitv::from_elem(9, false);
2298 assert_eq!(bv.to_bytes(), vec!(0b00100000, 0b10000000));
2302 fn test_from_bools() {
2303 let bools = vec![true, false, true, true];
2304 let bitv: Bitv = bools.iter().map(|n| *n).collect();
2305 assert_eq!(bitv.to_string(), "1011");
2309 fn test_to_bools() {
2310 let bools = vec!(false, false, true, false, false, true, true, false);
2311 assert_eq!(Bitv::from_bytes(&[0b00100110]).iter().collect::<Vec<bool>>(), bools);
2315 fn test_bitv_iterator() {
2316 let bools = vec![true, false, true, true];
2317 let bitv: Bitv = bools.iter().map(|n| *n).collect();
2319 assert_eq!(bitv.iter().collect::<Vec<bool>>(), bools);
2321 let long = Vec::from_fn(10000, |i| i % 2 == 0);
2322 let bitv: Bitv = long.iter().map(|n| *n).collect();
2323 assert_eq!(bitv.iter().collect::<Vec<bool>>(), long)
2327 fn test_small_difference() {
2328 let mut b1 = Bitv::from_elem(3, false);
2329 let mut b2 = Bitv::from_elem(3, false);
2334 assert!(b1.difference(&b2));
2341 fn test_big_difference() {
2342 let mut b1 = Bitv::from_elem(100, false);
2343 let mut b2 = Bitv::from_elem(100, false);
2348 assert!(b1.difference(&b2));
2355 fn test_small_clear() {
2356 let mut b = Bitv::from_elem(14, true);
2357 assert!(!b.none() && b.all());
2359 assert!(b.none() && !b.all());
2363 fn test_big_clear() {
2364 let mut b = Bitv::from_elem(140, true);
2365 assert!(!b.none() && b.all());
2367 assert!(b.none() && !b.all());
2372 let mut a = Bitv::from_elem(5u, false);
2373 let mut b = Bitv::from_elem(5u, false);
2375 assert!(!(a < b) && !(b < a));
2381 assert!(!(a < b) && b < a);
2388 let mut a = Bitv::from_elem(5u, false);
2389 let mut b = Bitv::from_elem(5u, false);
2391 assert!(a <= b && a >= b);
2393 assert!(a > b && a >= b);
2394 assert!(b < a && b <= a);
2397 assert!(b > a && b >= a);
2398 assert!(a < b && a <= b);
2403 fn test_small_bitv_tests() {
2404 let v = Bitv::from_bytes(&[0]);
2409 let v = Bitv::from_bytes(&[0b00010100]);
2414 let v = Bitv::from_bytes(&[0xFF]);
2421 fn test_big_bitv_tests() {
2422 let v = Bitv::from_bytes(&[ // 88 bits
2430 let v = Bitv::from_bytes(&[ // 88 bits
2431 0, 0, 0b00010100, 0,
2432 0, 0, 0, 0b00110100,
2438 let v = Bitv::from_bytes(&[ // 88 bits
2439 0xFF, 0xFF, 0xFF, 0xFF,
2440 0xFF, 0xFF, 0xFF, 0xFF,
2448 fn test_bitv_push_pop() {
2449 let mut s = Bitv::from_elem(5 * u32::BITS - 2, false);
2450 assert_eq!(s.len(), 5 * u32::BITS - 2);
2451 assert_eq!(s[5 * u32::BITS - 3], false);
2454 assert_eq!(s[5 * u32::BITS - 2], true);
2455 assert_eq!(s[5 * u32::BITS - 1], true);
2456 // Here the internal vector will need to be extended
2458 assert_eq!(s[5 * u32::BITS], false);
2460 assert_eq!(s[5 * u32::BITS + 1], false);
2461 assert_eq!(s.len(), 5 * u32::BITS + 2);
2463 assert_eq!(s.pop(), Some(false));
2464 assert_eq!(s.pop(), Some(false));
2465 assert_eq!(s.pop(), Some(true));
2466 assert_eq!(s.pop(), Some(true));
2467 assert_eq!(s.len(), 5 * u32::BITS - 2);
2471 fn test_bitv_truncate() {
2472 let mut s = Bitv::from_elem(5 * u32::BITS, true);
2474 assert_eq!(s, Bitv::from_elem(5 * u32::BITS, true));
2475 assert_eq!(s.len(), 5 * u32::BITS);
2476 s.truncate(4 * u32::BITS);
2477 assert_eq!(s, Bitv::from_elem(4 * u32::BITS, true));
2478 assert_eq!(s.len(), 4 * u32::BITS);
2479 // Truncating to a size > s.len() should be a noop
2480 s.truncate(5 * u32::BITS);
2481 assert_eq!(s, Bitv::from_elem(4 * u32::BITS, true));
2482 assert_eq!(s.len(), 4 * u32::BITS);
2483 s.truncate(3 * u32::BITS - 10);
2484 assert_eq!(s, Bitv::from_elem(3 * u32::BITS - 10, true));
2485 assert_eq!(s.len(), 3 * u32::BITS - 10);
2487 assert_eq!(s, Bitv::from_elem(0, true));
2488 assert_eq!(s.len(), 0);
2492 fn test_bitv_reserve() {
2493 let mut s = Bitv::from_elem(5 * u32::BITS, true);
2495 assert!(s.capacity() >= 5 * u32::BITS);
2496 s.reserve(2 * u32::BITS);
2497 assert!(s.capacity() >= 7 * u32::BITS);
2498 s.reserve(7 * u32::BITS);
2499 assert!(s.capacity() >= 12 * u32::BITS);
2500 s.reserve_exact(7 * u32::BITS);
2501 assert!(s.capacity() >= 12 * u32::BITS);
2502 s.reserve(7 * u32::BITS + 1);
2503 assert!(s.capacity() >= 12 * u32::BITS + 1);
2504 // Check that length hasn't changed
2505 assert_eq!(s.len(), 5 * u32::BITS);
2509 assert_eq!(s[5 * u32::BITS - 1], true);
2510 assert_eq!(s[5 * u32::BITS - 0], true);
2511 assert_eq!(s[5 * u32::BITS + 1], false);
2512 assert_eq!(s[5 * u32::BITS + 2], true);
2516 fn test_bitv_grow() {
2517 let mut bitv = Bitv::from_bytes(&[0b10110110, 0b00000000, 0b10101010]);
2518 bitv.grow(32, true);
2519 assert_eq!(bitv, Bitv::from_bytes(&[0b10110110, 0b00000000, 0b10101010,
2520 0xFF, 0xFF, 0xFF, 0xFF]));
2521 bitv.grow(64, false);
2522 assert_eq!(bitv, Bitv::from_bytes(&[0b10110110, 0b00000000, 0b10101010,
2523 0xFF, 0xFF, 0xFF, 0xFF, 0, 0, 0, 0, 0, 0, 0, 0]));
2524 bitv.grow(16, true);
2525 assert_eq!(bitv, Bitv::from_bytes(&[0b10110110, 0b00000000, 0b10101010,
2526 0xFF, 0xFF, 0xFF, 0xFF, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF]));
2530 fn test_bitv_extend() {
2531 let mut bitv = Bitv::from_bytes(&[0b10110110, 0b00000000, 0b11111111]);
2532 let ext = Bitv::from_bytes(&[0b01001001, 0b10010010, 0b10111101]);
2533 bitv.extend(ext.iter());
2534 assert_eq!(bitv, Bitv::from_bytes(&[0b10110110, 0b00000000, 0b11111111,
2535 0b01001001, 0b10010010, 0b10111101]));
2544 use std::prelude::v1::*;
2548 use test::{Bencher, black_box};
2552 static BENCH_BITS : uint = 1 << 14;
2554 fn rng() -> rand::IsaacRng {
2555 let seed: &[_] = &[1, 2, 3, 4, 5, 6, 7, 8, 9, 0];
2556 rand::SeedableRng::from_seed(seed)
2560 fn bench_uint_small(b: &mut Bencher) {
2562 let mut bitv = 0 as uint;
2564 for _ in range(0u, 100) {
2565 bitv |= 1 << ((r.next_u32() as uint) % u32::BITS);
2572 fn bench_bitv_set_big_fixed(b: &mut Bencher) {
2574 let mut bitv = Bitv::from_elem(BENCH_BITS, false);
2576 for _ in range(0u, 100) {
2577 bitv.set((r.next_u32() as uint) % BENCH_BITS, true);
2584 fn bench_bitv_set_big_variable(b: &mut Bencher) {
2586 let mut bitv = Bitv::from_elem(BENCH_BITS, false);
2588 for _ in range(0u, 100) {
2589 bitv.set((r.next_u32() as uint) % BENCH_BITS, r.gen());
2596 fn bench_bitv_set_small(b: &mut Bencher) {
2598 let mut bitv = Bitv::from_elem(u32::BITS, false);
2600 for _ in range(0u, 100) {
2601 bitv.set((r.next_u32() as uint) % u32::BITS, true);
2608 fn bench_bitv_big_union(b: &mut Bencher) {
2609 let mut b1 = Bitv::from_elem(BENCH_BITS, false);
2610 let b2 = Bitv::from_elem(BENCH_BITS, false);
2617 fn bench_bitv_small_iter(b: &mut Bencher) {
2618 let bitv = Bitv::from_elem(u32::BITS, false);
2621 for _ in range(0u, 10) {
2622 for pres in bitv.iter() {
2623 sum += pres as uint;
2631 fn bench_bitv_big_iter(b: &mut Bencher) {
2632 let bitv = Bitv::from_elem(BENCH_BITS, false);
2635 for pres in bitv.iter() {
2636 sum += pres as uint;
2652 use std::iter::range_step;
2654 use super::{Bitv, BitvSet};
2657 fn test_bitv_set_show() {
2658 let mut s = BitvSet::new();
2663 assert_eq!("{1, 2, 10, 50}", s.to_string());
2667 fn test_bitv_set_from_uints() {
2668 let uints = vec![0, 2, 2, 3];
2669 let a: BitvSet = uints.into_iter().collect();
2670 let mut b = BitvSet::new();
2678 fn test_bitv_set_iterator() {
2679 let uints = vec![0, 2, 2, 3];
2680 let bitv: BitvSet = uints.into_iter().collect();
2682 let idxs: Vec<uint> = bitv.iter().collect();
2683 assert_eq!(idxs, vec![0, 2, 3]);
2685 let long: BitvSet = range(0u, 10000).filter(|&n| n % 2 == 0).collect();
2686 let real = range_step(0, 10000, 2).collect::<Vec<uint>>();
2688 let idxs: Vec<uint> = long.iter().collect();
2689 assert_eq!(idxs, real);
2693 fn test_bitv_set_frombitv_init() {
2694 let bools = [true, false];
2695 let lengths = [10, 64, 100];
2696 for &b in bools.iter() {
2697 for &l in lengths.iter() {
2698 let bitset = BitvSet::from_bitv(Bitv::from_elem(l, b));
2699 assert_eq!(bitset.contains(&1u), b);
2700 assert_eq!(bitset.contains(&(l-1u)), b);
2701 assert!(!bitset.contains(&l));
2707 fn test_bitv_masking() {
2708 let b = Bitv::from_elem(140, true);
2709 let mut bs = BitvSet::from_bitv(b);
2710 assert!(bs.contains(&139));
2711 assert!(!bs.contains(&140));
2712 assert!(bs.insert(150));
2713 assert!(!bs.contains(&140));
2714 assert!(!bs.contains(&149));
2715 assert!(bs.contains(&150));
2716 assert!(!bs.contains(&151));
2720 fn test_bitv_set_basic() {
2721 let mut b = BitvSet::new();
2722 assert!(b.insert(3));
2723 assert!(!b.insert(3));
2724 assert!(b.contains(&3));
2725 assert!(b.insert(4));
2726 assert!(!b.insert(4));
2727 assert!(b.contains(&3));
2728 assert!(b.insert(400));
2729 assert!(!b.insert(400));
2730 assert!(b.contains(&400));
2731 assert_eq!(b.len(), 3);
2735 fn test_bitv_set_intersection() {
2736 let mut a = BitvSet::new();
2737 let mut b = BitvSet::new();
2739 assert!(a.insert(11));
2740 assert!(a.insert(1));
2741 assert!(a.insert(3));
2742 assert!(a.insert(77));
2743 assert!(a.insert(103));
2744 assert!(a.insert(5));
2746 assert!(b.insert(2));
2747 assert!(b.insert(11));
2748 assert!(b.insert(77));
2749 assert!(b.insert(5));
2750 assert!(b.insert(3));
2752 let expected = [3, 5, 11, 77];
2753 let actual = a.intersection(&b).collect::<Vec<uint>>();
2754 assert_eq!(actual, expected);
2758 fn test_bitv_set_difference() {
2759 let mut a = BitvSet::new();
2760 let mut b = BitvSet::new();
2762 assert!(a.insert(1));
2763 assert!(a.insert(3));
2764 assert!(a.insert(5));
2765 assert!(a.insert(200));
2766 assert!(a.insert(500));
2768 assert!(b.insert(3));
2769 assert!(b.insert(200));
2771 let expected = [1, 5, 500];
2772 let actual = a.difference(&b).collect::<Vec<uint>>();
2773 assert_eq!(actual, expected);
2777 fn test_bitv_set_symmetric_difference() {
2778 let mut a = BitvSet::new();
2779 let mut b = BitvSet::new();
2781 assert!(a.insert(1));
2782 assert!(a.insert(3));
2783 assert!(a.insert(5));
2784 assert!(a.insert(9));
2785 assert!(a.insert(11));
2787 assert!(b.insert(3));
2788 assert!(b.insert(9));
2789 assert!(b.insert(14));
2790 assert!(b.insert(220));
2792 let expected = [1, 5, 11, 14, 220];
2793 let actual = a.symmetric_difference(&b).collect::<Vec<uint>>();
2794 assert_eq!(actual, expected);
2798 fn test_bitv_set_union() {
2799 let mut a = BitvSet::new();
2800 let mut b = BitvSet::new();
2801 assert!(a.insert(1));
2802 assert!(a.insert(3));
2803 assert!(a.insert(5));
2804 assert!(a.insert(9));
2805 assert!(a.insert(11));
2806 assert!(a.insert(160));
2807 assert!(a.insert(19));
2808 assert!(a.insert(24));
2809 assert!(a.insert(200));
2811 assert!(b.insert(1));
2812 assert!(b.insert(5));
2813 assert!(b.insert(9));
2814 assert!(b.insert(13));
2815 assert!(b.insert(19));
2817 let expected = [1, 3, 5, 9, 11, 13, 19, 24, 160, 200];
2818 let actual = a.union(&b).collect::<Vec<uint>>();
2819 assert_eq!(actual, expected);
2823 fn test_bitv_set_subset() {
2824 let mut set1 = BitvSet::new();
2825 let mut set2 = BitvSet::new();
2827 assert!(set1.is_subset(&set2)); // {} {}
2829 assert!(set1.is_subset(&set2)); // {} { 1 }
2831 assert!(set1.is_subset(&set2)); // {} { 1, 2 }
2833 assert!(set1.is_subset(&set2)); // { 2 } { 1, 2 }
2835 assert!(!set1.is_subset(&set2)); // { 2, 3 } { 1, 2 }
2837 assert!(set1.is_subset(&set2)); // { 2, 3 } { 1, 2, 3 }
2839 assert!(set1.is_subset(&set2)); // { 2, 3 } { 1, 2, 3, 4 }
2841 assert!(set1.is_subset(&set2)); // { 2, 3 } { 2, 3, 4 }
2843 assert!(!set1.is_subset(&set2)); // { 2, 3 } { 2, 4 }
2845 assert!(set1.is_subset(&set2)); // { 2 } { 2, 4 }
2849 fn test_bitv_set_is_disjoint() {
2850 let a = BitvSet::from_bitv(Bitv::from_bytes(&[0b10100010]));
2851 let b = BitvSet::from_bitv(Bitv::from_bytes(&[0b01000000]));
2852 let c = BitvSet::new();
2853 let d = BitvSet::from_bitv(Bitv::from_bytes(&[0b00110000]));
2855 assert!(!a.is_disjoint(&d));
2856 assert!(!d.is_disjoint(&a));
2858 assert!(a.is_disjoint(&b));
2859 assert!(a.is_disjoint(&c));
2860 assert!(b.is_disjoint(&a));
2861 assert!(b.is_disjoint(&c));
2862 assert!(c.is_disjoint(&a));
2863 assert!(c.is_disjoint(&b));
2867 fn test_bitv_set_union_with() {
2868 //a should grow to include larger elements
2869 let mut a = BitvSet::new();
2871 let mut b = BitvSet::new();
2873 let expected = BitvSet::from_bitv(Bitv::from_bytes(&[0b10000100]));
2875 assert_eq!(a, expected);
2878 let mut a = BitvSet::from_bitv(Bitv::from_bytes(&[0b10100010]));
2879 let mut b = BitvSet::from_bitv(Bitv::from_bytes(&[0b01100010]));
2883 assert_eq!(a.len(), 4);
2884 assert_eq!(b.len(), 4);
2888 fn test_bitv_set_intersect_with() {
2889 // Explicitly 0'ed bits
2890 let mut a = BitvSet::from_bitv(Bitv::from_bytes(&[0b10100010]));
2891 let mut b = BitvSet::from_bitv(Bitv::from_bytes(&[0b00000000]));
2893 a.intersect_with(&b);
2894 b.intersect_with(&c);
2895 assert!(a.is_empty());
2896 assert!(b.is_empty());
2898 // Uninitialized bits should behave like 0's
2899 let mut a = BitvSet::from_bitv(Bitv::from_bytes(&[0b10100010]));
2900 let mut b = BitvSet::new();
2902 a.intersect_with(&b);
2903 b.intersect_with(&c);
2904 assert!(a.is_empty());
2905 assert!(b.is_empty());
2908 let mut a = BitvSet::from_bitv(Bitv::from_bytes(&[0b10100010]));
2909 let mut b = BitvSet::from_bitv(Bitv::from_bytes(&[0b01100010]));
2911 a.intersect_with(&b);
2912 b.intersect_with(&c);
2913 assert_eq!(a.len(), 2);
2914 assert_eq!(b.len(), 2);
2918 fn test_bitv_set_difference_with() {
2919 // Explicitly 0'ed bits
2920 let mut a = BitvSet::from_bitv(Bitv::from_bytes(&[0b00000000]));
2921 let b = BitvSet::from_bitv(Bitv::from_bytes(&[0b10100010]));
2922 a.difference_with(&b);
2923 assert!(a.is_empty());
2925 // Uninitialized bits should behave like 0's
2926 let mut a = BitvSet::new();
2927 let b = BitvSet::from_bitv(Bitv::from_bytes(&[0b11111111]));
2928 a.difference_with(&b);
2929 assert!(a.is_empty());
2932 let mut a = BitvSet::from_bitv(Bitv::from_bytes(&[0b10100010]));
2933 let mut b = BitvSet::from_bitv(Bitv::from_bytes(&[0b01100010]));
2935 a.difference_with(&b);
2936 b.difference_with(&c);
2937 assert_eq!(a.len(), 1);
2938 assert_eq!(b.len(), 1);
2942 fn test_bitv_set_symmetric_difference_with() {
2943 //a should grow to include larger elements
2944 let mut a = BitvSet::new();
2947 let mut b = BitvSet::new();
2950 let expected = BitvSet::from_bitv(Bitv::from_bytes(&[0b10000100]));
2951 a.symmetric_difference_with(&b);
2952 assert_eq!(a, expected);
2954 let mut a = BitvSet::from_bitv(Bitv::from_bytes(&[0b10100010]));
2955 let b = BitvSet::new();
2957 a.symmetric_difference_with(&b);
2961 let mut a = BitvSet::from_bitv(Bitv::from_bytes(&[0b11100010]));
2962 let mut b = BitvSet::from_bitv(Bitv::from_bytes(&[0b01101010]));
2964 a.symmetric_difference_with(&b);
2965 b.symmetric_difference_with(&c);
2966 assert_eq!(a.len(), 2);
2967 assert_eq!(b.len(), 2);
2971 fn test_bitv_set_eq() {
2972 let a = BitvSet::from_bitv(Bitv::from_bytes(&[0b10100010]));
2973 let b = BitvSet::from_bitv(Bitv::from_bytes(&[0b00000000]));
2974 let c = BitvSet::new();
2985 fn test_bitv_set_cmp() {
2986 let a = BitvSet::from_bitv(Bitv::from_bytes(&[0b10100010]));
2987 let b = BitvSet::from_bitv(Bitv::from_bytes(&[0b00000000]));
2988 let c = BitvSet::new();
2990 assert_eq!(a.cmp(&b), Greater);
2991 assert_eq!(a.cmp(&c), Greater);
2992 assert_eq!(b.cmp(&a), Less);
2993 assert_eq!(b.cmp(&c), Equal);
2994 assert_eq!(c.cmp(&a), Less);
2995 assert_eq!(c.cmp(&b), Equal);
2999 fn test_bitv_remove() {
3000 let mut a = BitvSet::new();
3002 assert!(a.insert(1));
3003 assert!(a.remove(&1));
3005 assert!(a.insert(100));
3006 assert!(a.remove(&100));
3008 assert!(a.insert(1000));
3009 assert!(a.remove(&1000));
3014 fn test_bitv_clone() {
3015 let mut a = BitvSet::new();
3017 assert!(a.insert(1));
3018 assert!(a.insert(100));
3019 assert!(a.insert(1000));
3021 let mut b = a.clone();
3025 assert!(b.remove(&1));
3026 assert!(a.contains(&1));
3028 assert!(a.remove(&1000));
3029 assert!(b.contains(&1000));
3038 mod bitv_set_bench {
3039 use std::prelude::v1::*;
3043 use test::{Bencher, black_box};
3045 use super::{Bitv, BitvSet};
3047 static BENCH_BITS : uint = 1 << 14;
3049 fn rng() -> rand::IsaacRng {
3050 let seed: &[_] = &[1, 2, 3, 4, 5, 6, 7, 8, 9, 0];
3051 rand::SeedableRng::from_seed(seed)
3055 fn bench_bitvset_small(b: &mut Bencher) {
3057 let mut bitv = BitvSet::new();
3059 for _ in range(0u, 100) {
3060 bitv.insert((r.next_u32() as uint) % u32::BITS);
3067 fn bench_bitvset_big(b: &mut Bencher) {
3069 let mut bitv = BitvSet::new();
3071 for _ in range(0u, 100) {
3072 bitv.insert((r.next_u32() as uint) % BENCH_BITS);
3079 fn bench_bitvset_iter(b: &mut Bencher) {
3080 let bitv = BitvSet::from_bitv(Bitv::from_fn(BENCH_BITS,
3081 |idx| {idx % 3 == 0}));
3084 for idx in bitv.iter() {