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rust/src/libcollections/bit.rs
Brian Anderson 76e9fa63ba core: Audit num module for int/uint 
* count_ones/zeros, trailing_ones/zeros return u32, not usize
* rotate_left/right take u32, not usize
* RADIX, MANTISSA_DIGITS, DIGITS, BITS, BYTES are u32, not usize

Doesn't touch pow because there's another PR for it.

[breaking-change]
2015-03-02 16:12:46 -08:00

3085 lines
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// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// FIXME(Gankro): BitVec and BitSet are very tightly coupled. Ideally (for
// maintenance), they should be in separate files/modules, with BitSet only
// using BitVec's public API. This will be hard for performance though, because
// `BitVec` will not want to leak its internal representation while its internal
// representation as `u32`s must be assumed for best performance.
// FIXME(tbu-): `BitVec`'s methods shouldn't be `union`, `intersection`, but
// rather `or` and `and`.
// (1) Be careful, most things can overflow here because the amount of bits in
// memory can overflow `usize`.
// (2) Make sure that the underlying vector has no excess length:
// E. g. `nbits == 16`, `storage.len() == 2` would be excess length,
// because the last word isn't used at all. This is important because some
// methods rely on it (for *CORRECTNESS*).
// (3) Make sure that the unused bits in the last word are zeroed out, again
// other methods rely on it for *CORRECTNESS*.
// (4) `BitSet` is tightly coupled with `BitVec`, so any changes you make in
// `BitVec` will need to be reflected in `BitSet`.
//! Collections implemented with bit vectors.
//!
//! # Examples
//!
//! This is a simple example of the [Sieve of Eratosthenes][sieve]
//! which calculates prime numbers up to a given limit.
//!
//! [sieve]: http://en.wikipedia.org/wiki/Sieve_of_Eratosthenes
//!
//! ```
//! use std::collections::{BitSet, BitVec};
//! use std::num::Float;
//! use std::iter;
//!
//! let max_prime = 10000;
//!
//! // Store the primes as a BitSet
//! let primes = {
//! // Assume all numbers are prime to begin, and then we
//! // cross off non-primes progressively
//! let mut bv = BitVec::from_elem(max_prime, true);
//!
//! // Neither 0 nor 1 are prime
//! bv.set(0, false);
//! bv.set(1, false);
//!
//! for i in iter::range_inclusive(2, (max_prime as f64).sqrt() as usize) {
//! // if i is a prime
//! if bv[i] {
//! // Mark all multiples of i as non-prime (any multiples below i * i
//! // will have been marked as non-prime previously)
//! for j in iter::range_step(i * i, max_prime, i) { bv.set(j, false) }
//! }
//! }
//! BitSet::from_bit_vec(bv)
//! };
//!
//! // Simple primality tests below our max bound
//! let print_primes = 20;
//! print!("The primes below {} are: ", print_primes);
//! for x in 0..print_primes {
//! if primes.contains(&x) {
//! print!("{} ", x);
//! }
//! }
//! println!("");
//!
//! // We can manipulate the internal BitVec
//! let num_primes = primes.get_ref().iter().filter(|x| *x).count();
//! println!("There are {} primes below {}", num_primes, max_prime);
//! ```
use core::prelude::*;
use core::cmp::Ordering;
use core::cmp;
use core::default::Default;
use core::fmt;
use core::hash;
use core::iter::RandomAccessIterator;
use core::iter::{Chain, Enumerate, Repeat, Skip, Take, repeat, Cloned};
use core::iter::{self, FromIterator, IntoIterator};
use core::num::Int;
use core::ops::Index;
use core::slice;
use core::{u8, u32, usize};
use bit_set; //so meta
use Vec;
type Blocks<'a> = Cloned<slice::Iter<'a, u32>>;
type MutBlocks<'a> = slice::IterMut<'a, u32>;
type MatchWords<'a> = Chain<Enumerate<Blocks<'a>>, Skip<Take<Enumerate<Repeat<u32>>>>>;
fn reverse_bits(byte: u8) -> u8 {
let mut result = 0;
for i in 0..u8::BITS {
result |= ((byte >> i) & 1) << (u8::BITS - 1 - i);
}
result
}
// Take two BitVec's, and return iterators of their words, where the shorter one
// has been padded with 0's
fn match_words <'a,'b>(a: &'a BitVec, b: &'b BitVec) -> (MatchWords<'a>, MatchWords<'b>) {
let a_len = a.storage.len();
let b_len = b.storage.len();
// have to uselessly pretend to pad the longer one for type matching
if a_len < b_len {
(a.blocks().enumerate().chain(iter::repeat(0u32).enumerate().take(b_len).skip(a_len)),
b.blocks().enumerate().chain(iter::repeat(0u32).enumerate().take(0).skip(0)))
} else {
(a.blocks().enumerate().chain(iter::repeat(0u32).enumerate().take(0).skip(0)),
b.blocks().enumerate().chain(iter::repeat(0u32).enumerate().take(a_len).skip(b_len)))
}
}
static TRUE: bool = true;
static FALSE: bool = false;
/// The bitvector type.
///
/// # Examples
///
/// ```rust
/// use std::collections::BitVec;
///
/// let mut bv = BitVec::from_elem(10, false);
///
/// // insert all primes less than 10
/// bv.set(2, true);
/// bv.set(3, true);
/// bv.set(5, true);
/// bv.set(7, true);
/// println!("{:?}", bv);
/// println!("total bits set to true: {}", bv.iter().filter(|x| *x).count());
///
/// // flip all values in bitvector, producing non-primes less than 10
/// bv.negate();
/// println!("{:?}", bv);
/// println!("total bits set to true: {}", bv.iter().filter(|x| *x).count());
///
/// // reset bitvector to empty
/// bv.clear();
/// println!("{:?}", bv);
/// println!("total bits set to true: {}", bv.iter().filter(|x| *x).count());
/// ```
#[unstable(feature = "collections",
reason = "RFC 509")]
pub struct BitVec {
/// Internal representation of the bit vector
storage: Vec<u32>,
/// The number of valid bits in the internal representation
nbits: usize
}
// FIXME(Gankro): NopeNopeNopeNopeNope (wait for IndexGet to be a thing)
impl Index<usize> for BitVec {
type Output = bool;
#[inline]
fn index(&self, i: &usize) -> &bool {
if self.get(*i).expect("index out of bounds") {
&TRUE
} else {
&FALSE
}
}
}
/// Computes how many blocks are needed to store that many bits
fn blocks_for_bits(bits: usize) -> usize {
// If we want 17 bits, dividing by 32 will produce 0. So we add 1 to make sure we
// reserve enough. But if we want exactly a multiple of 32, this will actually allocate
// one too many. So we need to check if that's the case. We can do that by computing if
// bitwise AND by `32 - 1` is 0. But LLVM should be able to optimize the semantically
// superior modulo operator on a power of two to this.
//
// Note that we can technically avoid this branch with the expression
// `(nbits + u32::BITS - 1) / 32::BITS`, but if nbits is almost usize::MAX this will overflow.
if bits % u32::BITS as usize == 0 {
bits / u32::BITS as usize
} else {
bits / u32::BITS as usize + 1
}
}
/// Computes the bitmask for the final word of the vector
fn mask_for_bits(bits: usize) -> u32 {
// Note especially that a perfect multiple of u32::BITS should mask all 1s.
!0u32 >> (u32::BITS as usize - bits % u32::BITS as usize) % u32::BITS as usize
}
impl BitVec {
/// Applies the given operation to the blocks of self and other, and sets
/// self to be the result. This relies on the caller not to corrupt the
/// last word.
#[inline]
fn process<F>(&mut self, other: &BitVec, mut op: F) -> bool where F: FnMut(u32, u32) -> u32 {
assert_eq!(self.len(), other.len());
// This could theoretically be a `debug_assert!`.
assert_eq!(self.storage.len(), other.storage.len());
let mut changed = false;
for (a, b) in self.blocks_mut().zip(other.blocks()) {
let w = op(*a, b);
if *a != w {
changed = true;
*a = w;
}
}
changed
}
/// Iterator over mutable refs to the underlying blocks of data.
fn blocks_mut(&mut self) -> MutBlocks {
// (2)
self.storage.iter_mut()
}
/// Iterator over the underlying blocks of data
fn blocks(&self) -> Blocks {
// (2)
self.storage.iter().cloned()
}
/// An operation might screw up the unused bits in the last block of the
/// `BitVec`. As per (3), it's assumed to be all 0s. This method fixes it up.
fn fix_last_block(&mut self) {
let extra_bits = self.len() % u32::BITS as usize;
if extra_bits > 0 {
let mask = (1 << extra_bits) - 1;
let storage_len = self.storage.len();
self.storage[storage_len - 1] &= mask;
}
}
/// Creates an empty `BitVec`.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
/// let mut bv = BitVec::new();
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn new() -> BitVec {
BitVec { storage: Vec::new(), nbits: 0 }
}
/// Creates a `BitVec` that holds `nbits` elements, setting each element
/// to `bit`.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let mut bv = BitVec::from_elem(10, false);
/// assert_eq!(bv.len(), 10);
/// for x in bv.iter() {
/// assert_eq!(x, false);
/// }
/// ```
pub fn from_elem(nbits: usize, bit: bool) -> BitVec {
let nblocks = blocks_for_bits(nbits);
let mut bit_vec = BitVec {
storage: repeat(if bit { !0u32 } else { 0u32 }).take(nblocks).collect(),
nbits: nbits
};
bit_vec.fix_last_block();
bit_vec
}
/// Constructs a new, empty `BitVec` with the specified capacity.
///
/// The bitvector will be able to hold at least `capacity` bits without
/// reallocating. If `capacity` is 0, it will not allocate.
///
/// It is important to note that this function does not specify the
/// *length* of the returned bitvector, but only the *capacity*.
#[stable(feature = "rust1", since = "1.0.0")]
pub fn with_capacity(nbits: usize) -> BitVec {
BitVec {
storage: Vec::with_capacity(blocks_for_bits(nbits)),
nbits: 0,
}
}
/// Transforms a byte-vector into a `BitVec`. Each byte becomes eight bits,
/// with the most significant bits of each byte coming first. Each
/// bit becomes `true` if equal to 1 or `false` if equal to 0.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let bv = BitVec::from_bytes(&[0b10100000, 0b00010010]);
/// assert!(bv.eq_vec(&[true, false, true, false,
/// false, false, false, false,
/// false, false, false, true,
/// false, false, true, false]));
/// ```
pub fn from_bytes(bytes: &[u8]) -> BitVec {
let len = bytes.len().checked_mul(u8::BITS as usize).expect("capacity overflow");
let mut bit_vec = BitVec::with_capacity(len);
let complete_words = bytes.len() / 4;
let extra_bytes = bytes.len() % 4;
bit_vec.nbits = len;
for i in 0..complete_words {
bit_vec.storage.push(
((reverse_bits(bytes[i * 4 + 0]) as u32) << 0) |
((reverse_bits(bytes[i * 4 + 1]) as u32) << 8) |
((reverse_bits(bytes[i * 4 + 2]) as u32) << 16) |
((reverse_bits(bytes[i * 4 + 3]) as u32) << 24)
);
}
if extra_bytes > 0 {
let mut last_word = 0u32;
for (i, &byte) in bytes[complete_words*4..].iter().enumerate() {
last_word |= (reverse_bits(byte) as u32) << (i * 8);
}
bit_vec.storage.push(last_word);
}
bit_vec
}
/// Creates a `BitVec` of the specified length where the value at each index
/// is `f(index)`.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let bv = BitVec::from_fn(5, |i| { i % 2 == 0 });
/// assert!(bv.eq_vec(&[true, false, true, false, true]));
/// ```
pub fn from_fn<F>(len: usize, mut f: F) -> BitVec where F: FnMut(usize) -> bool {
let mut bit_vec = BitVec::from_elem(len, false);
for i in 0..len {
bit_vec.set(i, f(i));
}
bit_vec
}
/// Retrieves the value at index `i`, or `None` if the index is out of bounds.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let bv = BitVec::from_bytes(&[0b01100000]);
/// assert_eq!(bv.get(0), Some(false));
/// assert_eq!(bv.get(1), Some(true));
/// assert_eq!(bv.get(100), None);
///
/// // Can also use array indexing
/// assert_eq!(bv[1], true);
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn get(&self, i: usize) -> Option<bool> {
if i >= self.nbits {
return None;
}
let w = i / u32::BITS as usize;
let b = i % u32::BITS as usize;
self.storage.get(w).map(|&block|
(block & (1 << b)) != 0
)
}
/// Sets the value of a bit at an index `i`.
///
/// # Panics
///
/// Panics if `i` is out of bounds.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let mut bv = BitVec::from_elem(5, false);
/// bv.set(3, true);
/// assert_eq!(bv[3], true);
/// ```
#[inline]
#[unstable(feature = "collections",
reason = "panic semantics are likely to change in the future")]
pub fn set(&mut self, i: usize, x: bool) {
assert!(i < self.nbits);
let w = i / u32::BITS as usize;
let b = i % u32::BITS as usize;
let flag = 1 << b;
let val = if x { self.storage[w] | flag }
else { self.storage[w] & !flag };
self.storage[w] = val;
}
/// Sets all bits to 1.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let before = 0b01100000;
/// let after = 0b11111111;
///
/// let mut bv = BitVec::from_bytes(&[before]);
/// bv.set_all();
/// assert_eq!(bv, BitVec::from_bytes(&[after]));
/// ```
#[inline]
pub fn set_all(&mut self) {
for w in &mut self.storage { *w = !0u32; }
self.fix_last_block();
}
/// Flips all bits.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let before = 0b01100000;
/// let after = 0b10011111;
///
/// let mut bv = BitVec::from_bytes(&[before]);
/// bv.negate();
/// assert_eq!(bv, BitVec::from_bytes(&[after]));
/// ```
#[inline]
pub fn negate(&mut self) {
for w in &mut self.storage { *w = !*w; }
self.fix_last_block();
}
/// Calculates the union of two bitvectors. This acts like the bitwise `or`
/// function.
///
/// Sets `self` to the union of `self` and `other`. Both bitvectors must be
/// the same length. Returns `true` if `self` changed.
///
/// # Panics
///
/// Panics if the bitvectors are of different lengths.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let a = 0b01100100;
/// let b = 0b01011010;
/// let res = 0b01111110;
///
/// let mut a = BitVec::from_bytes(&[a]);
/// let b = BitVec::from_bytes(&[b]);
///
/// assert!(a.union(&b));
/// assert_eq!(a, BitVec::from_bytes(&[res]));
/// ```
#[inline]
pub fn union(&mut self, other: &BitVec) -> bool {
self.process(other, |w1, w2| w1 | w2)
}
/// Calculates the intersection of two bitvectors. This acts like the
/// bitwise `and` function.
///
/// Sets `self` to the intersection of `self` and `other`. Both bitvectors
/// must be the same length. Returns `true` if `self` changed.
///
/// # Panics
///
/// Panics if the bitvectors are of different lengths.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let a = 0b01100100;
/// let b = 0b01011010;
/// let res = 0b01000000;
///
/// let mut a = BitVec::from_bytes(&[a]);
/// let b = BitVec::from_bytes(&[b]);
///
/// assert!(a.intersect(&b));
/// assert_eq!(a, BitVec::from_bytes(&[res]));
/// ```
#[inline]
pub fn intersect(&mut self, other: &BitVec) -> bool {
self.process(other, |w1, w2| w1 & w2)
}
/// Calculates the difference between two bitvectors.
///
/// Sets each element of `self` to the value of that element minus the
/// element of `other` at the same index. Both bitvectors must be the same
/// length. Returns `true` if `self` changed.
///
/// # Panics
///
/// Panics if the bitvectors are of different length.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let a = 0b01100100;
/// let b = 0b01011010;
/// let a_b = 0b00100100; // a - b
/// let b_a = 0b00011010; // b - a
///
/// let mut bva = BitVec::from_bytes(&[a]);
/// let bvb = BitVec::from_bytes(&[b]);
///
/// assert!(bva.difference(&bvb));
/// assert_eq!(bva, BitVec::from_bytes(&[a_b]));
///
/// let bva = BitVec::from_bytes(&[a]);
/// let mut bvb = BitVec::from_bytes(&[b]);
///
/// assert!(bvb.difference(&bva));
/// assert_eq!(bvb, BitVec::from_bytes(&[b_a]));
/// ```
#[inline]
pub fn difference(&mut self, other: &BitVec) -> bool {
self.process(other, |w1, w2| w1 & !w2)
}
/// Returns `true` if all bits are 1.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let mut bv = BitVec::from_elem(5, true);
/// assert_eq!(bv.all(), true);
///
/// bv.set(1, false);
/// assert_eq!(bv.all(), false);
/// ```
pub fn all(&self) -> bool {
let mut last_word = !0u32;
// Check that every block but the last is all-ones...
self.blocks().all(|elem| {
let tmp = last_word;
last_word = elem;
tmp == !0u32
// and then check the last one has enough ones
}) && (last_word == mask_for_bits(self.nbits))
}
/// Returns an iterator over the elements of the vector in order.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let bv = BitVec::from_bytes(&[0b01110100, 0b10010010]);
/// assert_eq!(bv.iter().filter(|x| *x).count(), 7);
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn iter(&self) -> Iter {
Iter { bit_vec: self, next_idx: 0, end_idx: self.nbits }
}
/// Returns `true` if all bits are 0.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let mut bv = BitVec::from_elem(10, false);
/// assert_eq!(bv.none(), true);
///
/// bv.set(3, true);
/// assert_eq!(bv.none(), false);
/// ```
pub fn none(&self) -> bool {
self.blocks().all(|w| w == 0)
}
/// Returns `true` if any bit is 1.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let mut bv = BitVec::from_elem(10, false);
/// assert_eq!(bv.any(), false);
///
/// bv.set(3, true);
/// assert_eq!(bv.any(), true);
/// ```
#[inline]
pub fn any(&self) -> bool {
!self.none()
}
/// Organises the bits into bytes, such that the first bit in the
/// `BitVec` becomes the high-order bit of the first byte. If the
/// size of the `BitVec` is not a multiple of eight then trailing bits
/// will be filled-in with `false`.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let mut bv = BitVec::from_elem(3, true);
/// bv.set(1, false);
///
/// assert_eq!(bv.to_bytes(), [0b10100000]);
///
/// let mut bv = BitVec::from_elem(9, false);
/// bv.set(2, true);
/// bv.set(8, true);
///
/// assert_eq!(bv.to_bytes(), [0b00100000, 0b10000000]);
/// ```
pub fn to_bytes(&self) -> Vec<u8> {
fn bit(bit_vec: &BitVec, byte: usize, bit: usize) -> u8 {
let offset = byte * 8 + bit;
if offset >= bit_vec.nbits {
0
} else {
(bit_vec[offset] as u8) << (7 - bit)
}
}
let len = self.nbits/8 +
if self.nbits % 8 == 0 { 0 } else { 1 };
(0..len).map(|i|
bit(self, i, 0) |
bit(self, i, 1) |
bit(self, i, 2) |
bit(self, i, 3) |
bit(self, i, 4) |
bit(self, i, 5) |
bit(self, i, 6) |
bit(self, i, 7)
).collect()
}
/// Compares a `BitVec` to a slice of `bool`s.
/// Both the `BitVec` and slice must have the same length.
///
/// # Panics
///
/// Panics if the `BitVec` and slice are of different length.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let bv = BitVec::from_bytes(&[0b10100000]);
///
/// assert!(bv.eq_vec(&[true, false, true, false,
/// false, false, false, false]));
/// ```
pub fn eq_vec(&self, v: &[bool]) -> bool {
assert_eq!(self.nbits, v.len());
iter::order::eq(self.iter(), v.iter().cloned())
}
/// Shortens a `BitVec`, dropping excess elements.
///
/// If `len` is greater than the vector's current length, this has no
/// effect.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let mut bv = BitVec::from_bytes(&[0b01001011]);
/// bv.truncate(2);
/// assert!(bv.eq_vec(&[false, true]));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn truncate(&mut self, len: usize) {
if len < self.len() {
self.nbits = len;
// This fixes (2).
self.storage.truncate(blocks_for_bits(len));
self.fix_last_block();
}
}
/// Reserves capacity for at least `additional` more bits to be inserted in the given
/// `BitVec`. The collection may reserve more space to avoid frequent reallocations.
///
/// # Panics
///
/// Panics if the new capacity overflows `usize`.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let mut bv = BitVec::from_elem(3, false);
/// bv.reserve(10);
/// assert_eq!(bv.len(), 3);
/// assert!(bv.capacity() >= 13);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn reserve(&mut self, additional: usize) {
let desired_cap = self.len().checked_add(additional).expect("capacity overflow");
let storage_len = self.storage.len();
if desired_cap > self.capacity() {
self.storage.reserve(blocks_for_bits(desired_cap) - storage_len);
}
}
/// Reserves the minimum capacity for exactly `additional` more bits to be inserted in the
/// given `BitVec`. Does nothing if the capacity is already sufficient.
///
/// Note that the allocator may give the collection more space than it requests. Therefore
/// capacity can not be relied upon to be precisely minimal. Prefer `reserve` if future
/// insertions are expected.
///
/// # Panics
///
/// Panics if the new capacity overflows `usize`.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let mut bv = BitVec::from_elem(3, false);
/// bv.reserve(10);
/// assert_eq!(bv.len(), 3);
/// assert!(bv.capacity() >= 13);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn reserve_exact(&mut self, additional: usize) {
let desired_cap = self.len().checked_add(additional).expect("capacity overflow");
let storage_len = self.storage.len();
if desired_cap > self.capacity() {
self.storage.reserve_exact(blocks_for_bits(desired_cap) - storage_len);
}
}
/// Returns the capacity in bits for this bit vector. Inserting any
/// element less than this amount will not trigger a resizing.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let mut bv = BitVec::new();
/// bv.reserve(10);
/// assert!(bv.capacity() >= 10);
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn capacity(&self) -> usize {
self.storage.capacity().checked_mul(u32::BITS as usize).unwrap_or(usize::MAX)
}
/// Grows the `BitVec` in-place, adding `n` copies of `value` to the `BitVec`.
///
/// # Panics
///
/// Panics if the new len overflows a `usize`.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let mut bv = BitVec::from_bytes(&[0b01001011]);
/// bv.grow(2, true);
/// assert_eq!(bv.len(), 10);
/// assert_eq!(bv.to_bytes(), [0b01001011, 0b11000000]);
/// ```
pub fn grow(&mut self, n: usize, value: bool) {
// Note: we just bulk set all the bits in the last word in this fn in multiple places
// which is technically wrong if not all of these bits are to be used. However, at the end
// of this fn we call `fix_last_block` at the end of this fn, which should fix this.
let new_nbits = self.nbits.checked_add(n).expect("capacity overflow");
let new_nblocks = blocks_for_bits(new_nbits);
let full_value = if value { !0 } else { 0 };
// Correct the old tail word, setting or clearing formerly unused bits
let old_last_word = blocks_for_bits(self.nbits) - 1;
if self.nbits % u32::BITS as usize > 0 {
let mask = mask_for_bits(self.nbits);
if value {
self.storage[old_last_word] |= !mask;
} else {
// Extra bits are already zero by invariant.
}
}
// Fill in words after the old tail word
let stop_idx = cmp::min(self.storage.len(), new_nblocks);
for idx in old_last_word + 1..stop_idx {
self.storage[idx] = full_value;
}
// Allocate new words, if needed
if new_nblocks > self.storage.len() {
let to_add = new_nblocks - self.storage.len();
self.storage.extend(repeat(full_value).take(to_add));
}
// Adjust internal bit count
self.nbits = new_nbits;
self.fix_last_block();
}
/// Removes the last bit from the BitVec, and returns it. Returns None if the BitVec is empty.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let mut bv = BitVec::from_bytes(&[0b01001001]);
/// assert_eq!(bv.pop(), Some(true));
/// assert_eq!(bv.pop(), Some(false));
/// assert_eq!(bv.len(), 6);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn pop(&mut self) -> Option<bool> {
if self.is_empty() {
None
} else {
let i = self.nbits - 1;
let ret = self[i];
// (3)
self.set(i, false);
self.nbits = i;
if self.nbits % u32::BITS as usize == 0 {
// (2)
self.storage.pop();
}
Some(ret)
}
}
/// Pushes a `bool` onto the end.
///
/// # Examples
///
/// ```
/// use std::collections::BitVec;
///
/// let mut bv = BitVec::new();
/// bv.push(true);
/// bv.push(false);
/// assert!(bv.eq_vec(&[true, false]));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn push(&mut self, elem: bool) {
if self.nbits % u32::BITS as usize == 0 {
self.storage.push(0);
}
let insert_pos = self.nbits;
self.nbits = self.nbits.checked_add(1).expect("Capacity overflow");
self.set(insert_pos, elem);
}
/// Return the total number of bits in this vector
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn len(&self) -> usize { self.nbits }
/// Returns true if there are no bits in this vector
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn is_empty(&self) -> bool { self.len() == 0 }
/// Clears all bits in this vector.
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn clear(&mut self) {
for w in &mut self.storage { *w = 0u32; }
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Default for BitVec {
#[inline]
fn default() -> BitVec { BitVec::new() }
}
#[stable(feature = "rust1", since = "1.0.0")]
impl FromIterator<bool> for BitVec {
fn from_iter<I: IntoIterator<Item=bool>>(iter: I) -> BitVec {
let mut ret = BitVec::new();
ret.extend(iter);
ret
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Extend<bool> for BitVec {
#[inline]
fn extend<I: IntoIterator<Item=bool>>(&mut self, iterable: I) {
let iterator = iterable.into_iter();
let (min, _) = iterator.size_hint();
self.reserve(min);
for element in iterator {
self.push(element)
}
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Clone for BitVec {
#[inline]
fn clone(&self) -> BitVec {
BitVec { storage: self.storage.clone(), nbits: self.nbits }
}
#[inline]
fn clone_from(&mut self, source: &BitVec) {
self.nbits = source.nbits;
self.storage.clone_from(&source.storage);
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl PartialOrd for BitVec {
#[inline]
fn partial_cmp(&self, other: &BitVec) -> Option<Ordering> {
iter::order::partial_cmp(self.iter(), other.iter())
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Ord for BitVec {
#[inline]
fn cmp(&self, other: &BitVec) -> Ordering {
iter::order::cmp(self.iter(), other.iter())
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Debug for BitVec {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
for bit in self {
try!(write!(fmt, "{}", if bit { 1 } else { 0 }));
}
Ok(())
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl hash::Hash for BitVec {
fn hash<H: hash::Hasher>(&self, state: &mut H) {
self.nbits.hash(state);
for elem in self.blocks() {
elem.hash(state);
}
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl cmp::PartialEq for BitVec {
#[inline]
fn eq(&self, other: &BitVec) -> bool {
if self.nbits != other.nbits {
return false;
}
self.blocks().zip(other.blocks()).all(|(w1, w2)| w1 == w2)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl cmp::Eq for BitVec {}
/// An iterator for `BitVec`.
#[stable(feature = "rust1", since = "1.0.0")]
#[derive(Clone)]
pub struct Iter<'a> {
bit_vec: &'a BitVec,
next_idx: usize,
end_idx: usize,
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> Iterator for Iter<'a> {
type Item = bool;
#[inline]
fn next(&mut self) -> Option<bool> {
if self.next_idx != self.end_idx {
let idx = self.next_idx;
self.next_idx += 1;
Some(self.bit_vec[idx])
} else {
None
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
let rem = self.end_idx - self.next_idx;
(rem, Some(rem))
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> DoubleEndedIterator for Iter<'a> {
#[inline]
fn next_back(&mut self) -> Option<bool> {
if self.next_idx != self.end_idx {
self.end_idx -= 1;
Some(self.bit_vec[self.end_idx])
} else {
None
}
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> ExactSizeIterator for Iter<'a> {}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> RandomAccessIterator for Iter<'a> {
#[inline]
fn indexable(&self) -> usize {
self.end_idx - self.next_idx
}
#[inline]
fn idx(&mut self, index: usize) -> Option<bool> {
if index >= self.indexable() {
None
} else {
Some(self.bit_vec[index])
}
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> IntoIterator for &'a BitVec {
type Item = bool;
type IntoIter = Iter<'a>;
fn into_iter(self) -> Iter<'a> {
self.iter()
}
}
/// An implementation of a set using a bit vector as an underlying
/// representation for holding unsigned numerical elements.
///
/// It should also be noted that the amount of storage necessary for holding a
/// set of objects is proportional to the maximum of the objects when viewed
/// as a `usize`.
///
/// # Examples
///
/// ```
/// use std::collections::{BitSet, BitVec};
///
/// // It's a regular set
/// let mut s = BitSet::new();
/// s.insert(0);
/// s.insert(3);
/// s.insert(7);
///
/// s.remove(&7);
///
/// if !s.contains(&7) {
/// println!("There is no 7");
/// }
///
/// // Can initialize from a `BitVec`
/// let other = BitSet::from_bit_vec(BitVec::from_bytes(&[0b11010000]));
///
/// s.union_with(&other);
///
/// // Print 0, 1, 3 in some order
/// for x in s.iter() {
/// println!("{}", x);
/// }
///
/// // Can convert back to a `BitVec`
/// let bv: BitVec = s.into_bit_vec();
/// assert!(bv[3]);
/// ```
#[derive(Clone)]
#[unstable(feature = "collections",
reason = "RFC 509")]
pub struct BitSet {
bit_vec: BitVec,
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Default for BitSet {
#[inline]
fn default() -> BitSet { BitSet::new() }
}
#[stable(feature = "rust1", since = "1.0.0")]
impl FromIterator<usize> for BitSet {
fn from_iter<I: IntoIterator<Item=usize>>(iter: I) -> BitSet {
let mut ret = BitSet::new();
ret.extend(iter);
ret
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Extend<usize> for BitSet {
#[inline]
fn extend<I: IntoIterator<Item=usize>>(&mut self, iter: I) {
for i in iter {
self.insert(i);
}
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl PartialOrd for BitSet {
#[inline]
fn partial_cmp(&self, other: &BitSet) -> Option<Ordering> {
let (a_iter, b_iter) = match_words(self.get_ref(), other.get_ref());
iter::order::partial_cmp(a_iter, b_iter)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Ord for BitSet {
#[inline]
fn cmp(&self, other: &BitSet) -> Ordering {
let (a_iter, b_iter) = match_words(self.get_ref(), other.get_ref());
iter::order::cmp(a_iter, b_iter)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl cmp::PartialEq for BitSet {
#[inline]
fn eq(&self, other: &BitSet) -> bool {
let (a_iter, b_iter) = match_words(self.get_ref(), other.get_ref());
iter::order::eq(a_iter, b_iter)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl cmp::Eq for BitSet {}
impl BitSet {
/// Creates a new empty `BitSet`.
///
/// # Examples
///
/// ```
/// use std::collections::BitSet;
///
/// let mut s = BitSet::new();
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn new() -> BitSet {
BitSet { bit_vec: BitVec::new() }
}
/// Creates a new `BitSet` with initially no contents, able to
/// hold `nbits` elements without resizing.
///
/// # Examples
///
/// ```
/// use std::collections::BitSet;
///
/// let mut s = BitSet::with_capacity(100);
/// assert!(s.capacity() >= 100);
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn with_capacity(nbits: usize) -> BitSet {
let bit_vec = BitVec::from_elem(nbits, false);
BitSet::from_bit_vec(bit_vec)
}
/// Creates a new `BitSet` from the given bit vector.
///
/// # Examples
///
/// ```
/// use std::collections::{BitVec, BitSet};
///
/// let bv = BitVec::from_bytes(&[0b01100000]);
/// let s = BitSet::from_bit_vec(bv);
///
/// // Print 1, 2 in arbitrary order
/// for x in s.iter() {
/// println!("{}", x);
/// }
/// ```
#[inline]
pub fn from_bit_vec(bit_vec: BitVec) -> BitSet {
BitSet { bit_vec: bit_vec }
}
/// Deprecated: use `from_bit_vec`.
#[inline]
#[deprecated(since = "1.0.0", reason = "renamed to from_bit_vec")]
#[unstable(feature = "collections")]
pub fn from_bitv(bit_vec: BitVec) -> BitSet {
BitSet { bit_vec: bit_vec }
}
/// Returns the capacity in bits for this bit vector. Inserting any
/// element less than this amount will not trigger a resizing.
///
/// # Examples
///
/// ```
/// use std::collections::BitSet;
///
/// let mut s = BitSet::with_capacity(100);
/// assert!(s.capacity() >= 100);
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn capacity(&self) -> usize {
self.bit_vec.capacity()
}
/// Reserves capacity for the given `BitSet` to contain `len` distinct elements. In the case
/// of `BitSet` this means reallocations will not occur as long as all inserted elements
/// are less than `len`.
///
/// The collection may reserve more space to avoid frequent reallocations.
///
///
/// # Examples
///
/// ```
/// use std::collections::BitSet;
///
/// let mut s = BitSet::new();
/// s.reserve_len(10);
/// assert!(s.capacity() >= 10);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn reserve_len(&mut self, len: usize) {
let cur_len = self.bit_vec.len();
if len >= cur_len {
self.bit_vec.reserve(len - cur_len);
}
}
/// Reserves the minimum capacity for the given `BitSet` to contain `len` distinct elements.
/// In the case of `BitSet` this means reallocations will not occur as long as all inserted
/// elements are less than `len`.
///
/// Note that the allocator may give the collection more space than it requests. Therefore
/// capacity can not be relied upon to be precisely minimal. Prefer `reserve_len` if future
/// insertions are expected.
///
///
/// # Examples
///
/// ```
/// use std::collections::BitSet;
///
/// let mut s = BitSet::new();
/// s.reserve_len_exact(10);
/// assert!(s.capacity() >= 10);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn reserve_len_exact(&mut self, len: usize) {
let cur_len = self.bit_vec.len();
if len >= cur_len {
self.bit_vec.reserve_exact(len - cur_len);
}
}
/// Consumes this set to return the underlying bit vector.
///
/// # Examples
///
/// ```
/// use std::collections::BitSet;
///
/// let mut s = BitSet::new();
/// s.insert(0);
/// s.insert(3);
///
/// let bv = s.into_bit_vec();
/// assert!(bv[0]);
/// assert!(bv[3]);
/// ```
#[inline]
pub fn into_bit_vec(self) -> BitVec {
self.bit_vec
}
/// Returns a reference to the underlying bit vector.
///
/// # Examples
///
/// ```
/// use std::collections::BitSet;
///
/// let mut s = BitSet::new();
/// s.insert(0);
///
/// let bv = s.get_ref();
/// assert_eq!(bv[0], true);
/// ```
#[inline]
pub fn get_ref(&self) -> &BitVec {
&self.bit_vec
}
#[inline]
fn other_op<F>(&mut self, other: &BitSet, mut f: F) where F: FnMut(u32, u32) -> u32 {
// Unwrap BitVecs
let self_bit_vec = &mut self.bit_vec;
let other_bit_vec = &other.bit_vec;
let self_len = self_bit_vec.len();
let other_len = other_bit_vec.len();
// Expand the vector if necessary
if self_len < other_len {
self_bit_vec.grow(other_len - self_len, false);
}
// virtually pad other with 0's for equal lengths
let other_words = {
let (_, result) = match_words(self_bit_vec, other_bit_vec);
result
};
// Apply values found in other
for (i, w) in other_words {
let old = self_bit_vec.storage[i];
let new = f(old, w);
self_bit_vec.storage[i] = new;
}
}
/// Truncates the underlying vector to the least length required.
///
/// # Examples
///
/// ```
/// use std::collections::BitSet;
///
/// let mut s = BitSet::new();
/// s.insert(32183231);
/// s.remove(&32183231);
///
/// // Internal storage will probably be bigger than necessary
/// println!("old capacity: {}", s.capacity());
///
/// // Now should be smaller
/// s.shrink_to_fit();
/// println!("new capacity: {}", s.capacity());
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn shrink_to_fit(&mut self) {
let bit_vec = &mut self.bit_vec;
// Obtain original length
let old_len = bit_vec.storage.len();
// Obtain coarse trailing zero length
let n = bit_vec.storage.iter().rev().take_while(|&&n| n == 0).count();
// Truncate
let trunc_len = cmp::max(old_len - n, 1);
bit_vec.storage.truncate(trunc_len);
bit_vec.nbits = trunc_len * u32::BITS as usize;
}
/// Iterator over each u32 stored in the `BitSet`.
///
/// # Examples
///
/// ```
/// use std::collections::{BitVec, BitSet};
///
/// let s = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01001010]));
///
/// // Print 1, 4, 6 in arbitrary order
/// for x in s.iter() {
/// println!("{}", x);
/// }
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn iter(&self) -> bit_set::Iter {
SetIter {set: self, next_idx: 0}
}
/// Iterator over each u32 stored in `self` union `other`.
/// See [union_with](#method.union_with) for an efficient in-place version.
///
/// # Examples
///
/// ```
/// use std::collections::{BitVec, BitSet};
///
/// let a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01101000]));
/// let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100000]));
///
/// // Print 0, 1, 2, 4 in arbitrary order
/// for x in a.union(&b) {
/// println!("{}", x);
/// }
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn union<'a>(&'a self, other: &'a BitSet) -> Union<'a> {
fn or(w1: u32, w2: u32) -> u32 { w1 | w2 }
Union(TwoBitPositions {
set: self,
other: other,
merge: or,
current_word: 0,
next_idx: 0
})
}
/// Iterator over each usize stored in `self` intersect `other`.
/// See [intersect_with](#method.intersect_with) for an efficient in-place version.
///
/// # Examples
///
/// ```
/// use std::collections::{BitVec, BitSet};
///
/// let a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01101000]));
/// let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100000]));
///
/// // Print 2
/// for x in a.intersection(&b) {
/// println!("{}", x);
/// }
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn intersection<'a>(&'a self, other: &'a BitSet) -> Intersection<'a> {
fn bitand(w1: u32, w2: u32) -> u32 { w1 & w2 }
let min = cmp::min(self.bit_vec.len(), other.bit_vec.len());
Intersection(TwoBitPositions {
set: self,
other: other,
merge: bitand,
current_word: 0,
next_idx: 0
}.take(min))
}
/// Iterator over each usize stored in the `self` setminus `other`.
/// See [difference_with](#method.difference_with) for an efficient in-place version.
///
/// # Examples
///
/// ```
/// use std::collections::{BitSet, BitVec};
///
/// let a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01101000]));
/// let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100000]));
///
/// // Print 1, 4 in arbitrary order
/// for x in a.difference(&b) {
/// println!("{}", x);
/// }
///
/// // Note that difference is not symmetric,
/// // and `b - a` means something else.
/// // This prints 0
/// for x in b.difference(&a) {
/// println!("{}", x);
/// }
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn difference<'a>(&'a self, other: &'a BitSet) -> Difference<'a> {
fn diff(w1: u32, w2: u32) -> u32 { w1 & !w2 }
Difference(TwoBitPositions {
set: self,
other: other,
merge: diff,
current_word: 0,
next_idx: 0
})
}
/// Iterator over each u32 stored in the symmetric difference of `self` and `other`.
/// See [symmetric_difference_with](#method.symmetric_difference_with) for
/// an efficient in-place version.
///
/// # Examples
///
/// ```
/// use std::collections::{BitSet, BitVec};
///
/// let a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01101000]));
/// let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100000]));
///
/// // Print 0, 1, 4 in arbitrary order
/// for x in a.symmetric_difference(&b) {
/// println!("{}", x);
/// }
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn symmetric_difference<'a>(&'a self, other: &'a BitSet) -> SymmetricDifference<'a> {
fn bitxor(w1: u32, w2: u32) -> u32 { w1 ^ w2 }
SymmetricDifference(TwoBitPositions {
set: self,
other: other,
merge: bitxor,
current_word: 0,
next_idx: 0
})
}
/// Unions in-place with the specified other bit vector.
///
/// # Examples
///
/// ```
/// use std::collections::{BitSet, BitVec};
///
/// let a = 0b01101000;
/// let b = 0b10100000;
/// let res = 0b11101000;
///
/// let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[a]));
/// let b = BitSet::from_bit_vec(BitVec::from_bytes(&[b]));
/// let res = BitSet::from_bit_vec(BitVec::from_bytes(&[res]));
///
/// a.union_with(&b);
/// assert_eq!(a, res);
/// ```
#[inline]
pub fn union_with(&mut self, other: &BitSet) {
self.other_op(other, |w1, w2| w1 | w2);
}
/// Intersects in-place with the specified other bit vector.
///
/// # Examples
///
/// ```
/// use std::collections::{BitSet, BitVec};
///
/// let a = 0b01101000;
/// let b = 0b10100000;
/// let res = 0b00100000;
///
/// let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[a]));
/// let b = BitSet::from_bit_vec(BitVec::from_bytes(&[b]));
/// let res = BitSet::from_bit_vec(BitVec::from_bytes(&[res]));
///
/// a.intersect_with(&b);
/// assert_eq!(a, res);
/// ```
#[inline]
pub fn intersect_with(&mut self, other: &BitSet) {
self.other_op(other, |w1, w2| w1 & w2);
}
/// Makes this bit vector the difference with the specified other bit vector
/// in-place.
///
/// # Examples
///
/// ```
/// use std::collections::{BitSet, BitVec};
///
/// let a = 0b01101000;
/// let b = 0b10100000;
/// let a_b = 0b01001000; // a - b
/// let b_a = 0b10000000; // b - a
///
/// let mut bva = BitSet::from_bit_vec(BitVec::from_bytes(&[a]));
/// let bvb = BitSet::from_bit_vec(BitVec::from_bytes(&[b]));
/// let bva_b = BitSet::from_bit_vec(BitVec::from_bytes(&[a_b]));
/// let bvb_a = BitSet::from_bit_vec(BitVec::from_bytes(&[b_a]));
///
/// bva.difference_with(&bvb);
/// assert_eq!(bva, bva_b);
///
/// let bva = BitSet::from_bit_vec(BitVec::from_bytes(&[a]));
/// let mut bvb = BitSet::from_bit_vec(BitVec::from_bytes(&[b]));
///
/// bvb.difference_with(&bva);
/// assert_eq!(bvb, bvb_a);
/// ```
#[inline]
pub fn difference_with(&mut self, other: &BitSet) {
self.other_op(other, |w1, w2| w1 & !w2);
}
/// Makes this bit vector the symmetric difference with the specified other
/// bit vector in-place.
///
/// # Examples
///
/// ```
/// use std::collections::{BitSet, BitVec};
///
/// let a = 0b01101000;
/// let b = 0b10100000;
/// let res = 0b11001000;
///
/// let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[a]));
/// let b = BitSet::from_bit_vec(BitVec::from_bytes(&[b]));
/// let res = BitSet::from_bit_vec(BitVec::from_bytes(&[res]));
///
/// a.symmetric_difference_with(&b);
/// assert_eq!(a, res);
/// ```
#[inline]
pub fn symmetric_difference_with(&mut self, other: &BitSet) {
self.other_op(other, |w1, w2| w1 ^ w2);
}
/// Return the number of set bits in this set.
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn len(&self) -> usize {
self.bit_vec.blocks().fold(0, |acc, n| acc + n.count_ones() as usize)
}
/// Returns whether there are no bits set in this set
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn is_empty(&self) -> bool {
self.bit_vec.none()
}
/// Clears all bits in this set
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn clear(&mut self) {
self.bit_vec.clear();
}
/// Returns `true` if this set contains the specified integer.
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn contains(&self, value: &usize) -> bool {
let bit_vec = &self.bit_vec;
*value < bit_vec.nbits && bit_vec[*value]
}
/// Returns `true` if the set has no elements in common with `other`.
/// This is equivalent to checking for an empty intersection.
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn is_disjoint(&self, other: &BitSet) -> bool {
self.intersection(other).next().is_none()
}
/// Returns `true` if the set is a subset of another.
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn is_subset(&self, other: &BitSet) -> bool {
let self_bit_vec = &self.bit_vec;
let other_bit_vec = &other.bit_vec;
let other_blocks = blocks_for_bits(other_bit_vec.len());
// Check that `self` intersect `other` is self
self_bit_vec.blocks().zip(other_bit_vec.blocks()).all(|(w1, w2)| w1 & w2 == w1) &&
// Make sure if `self` has any more blocks than `other`, they're all 0
self_bit_vec.blocks().skip(other_blocks).all(|w| w == 0)
}
/// Returns `true` if the set is a superset of another.
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn is_superset(&self, other: &BitSet) -> bool {
other.is_subset(self)
}
/// Adds a value to the set. Returns `true` if the value was not already
/// present in the set.
#[stable(feature = "rust1", since = "1.0.0")]
pub fn insert(&mut self, value: usize) -> bool {
if self.contains(&value) {
return false;
}
// Ensure we have enough space to hold the new element
let len = self.bit_vec.len();
if value >= len {
self.bit_vec.grow(value - len + 1, false)
}
self.bit_vec.set(value, true);
return true;
}
/// Removes a value from the set. Returns `true` if the value was
/// present in the set.
#[stable(feature = "rust1", since = "1.0.0")]
pub fn remove(&mut self, value: &usize) -> bool {
if !self.contains(value) {
return false;
}
self.bit_vec.set(*value, false);
return true;
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Debug for BitSet {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
try!(write!(fmt, "{{"));
let mut first = true;
for n in self {
if !first {
try!(write!(fmt, ", "));
}
try!(write!(fmt, "{:?}", n));
first = false;
}
write!(fmt, "}}")
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl hash::Hash for BitSet {
fn hash<H: hash::Hasher>(&self, state: &mut H) {
for pos in self {
pos.hash(state);
}
}
}
/// An iterator for `BitSet`.
#[derive(Clone)]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct SetIter<'a> {
set: &'a BitSet,
next_idx: usize
}
/// An iterator combining two `BitSet` iterators.
#[derive(Clone)]
struct TwoBitPositions<'a> {
set: &'a BitSet,
other: &'a BitSet,
merge: fn(u32, u32) -> u32,
current_word: u32,
next_idx: usize
}
#[stable(feature = "rust1", since = "1.0.0")]
pub struct Union<'a>(TwoBitPositions<'a>);
#[stable(feature = "rust1", since = "1.0.0")]
pub struct Intersection<'a>(Take<TwoBitPositions<'a>>);
#[stable(feature = "rust1", since = "1.0.0")]
pub struct Difference<'a>(TwoBitPositions<'a>);
#[stable(feature = "rust1", since = "1.0.0")]
pub struct SymmetricDifference<'a>(TwoBitPositions<'a>);
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> Iterator for SetIter<'a> {
type Item = usize;
fn next(&mut self) -> Option<usize> {
while self.next_idx < self.set.bit_vec.len() {
let idx = self.next_idx;
self.next_idx += 1;
if self.set.contains(&idx) {
return Some(idx);
}
}
return None;
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
(0, Some(self.set.bit_vec.len() - self.next_idx))
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> Iterator for TwoBitPositions<'a> {
type Item = usize;
fn next(&mut self) -> Option<usize> {
while self.next_idx < self.set.bit_vec.len() ||
self.next_idx < self.other.bit_vec.len() {
let bit_idx = self.next_idx % u32::BITS as usize;
if bit_idx == 0 {
let s_bit_vec = &self.set.bit_vec;
let o_bit_vec = &self.other.bit_vec;
// Merging the two words is a bit of an awkward dance since
// one BitVec might be longer than the other
let word_idx = self.next_idx / u32::BITS as usize;
let w1 = if word_idx < s_bit_vec.storage.len() {
s_bit_vec.storage[word_idx]
} else { 0 };
let w2 = if word_idx < o_bit_vec.storage.len() {
o_bit_vec.storage[word_idx]
} else { 0 };
self.current_word = (self.merge)(w1, w2);
}
self.next_idx += 1;
if self.current_word & (1 << bit_idx) != 0 {
return Some(self.next_idx - 1);
}
}
return None;
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
let cap = cmp::max(self.set.bit_vec.len(), self.other.bit_vec.len());
(0, Some(cap - self.next_idx))
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> Iterator for Union<'a> {
type Item = usize;
#[inline] fn next(&mut self) -> Option<usize> { self.0.next() }
#[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.0.size_hint() }
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> Iterator for Intersection<'a> {
type Item = usize;
#[inline] fn next(&mut self) -> Option<usize> { self.0.next() }
#[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.0.size_hint() }
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> Iterator for Difference<'a> {
type Item = usize;
#[inline] fn next(&mut self) -> Option<usize> { self.0.next() }
#[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.0.size_hint() }
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> Iterator for SymmetricDifference<'a> {
type Item = usize;
#[inline] fn next(&mut self) -> Option<usize> { self.0.next() }
#[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.0.size_hint() }
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> IntoIterator for &'a BitSet {
type Item = usize;
type IntoIter = SetIter<'a>;
fn into_iter(self) -> SetIter<'a> {
self.iter()
}
}
#[cfg(test)]
mod tests {
use prelude::*;
use core::u32;
use super::BitVec;
#[test]
fn test_to_str() {
let zerolen = BitVec::new();
assert_eq!(format!("{:?}", zerolen), "");
let eightbits = BitVec::from_elem(8, false);
assert_eq!(format!("{:?}", eightbits), "00000000")
}
#[test]
fn test_0_elements() {
let act = BitVec::new();
let exp = Vec::new();
assert!(act.eq_vec(&exp));
assert!(act.none() && act.all());
}
#[test]
fn test_1_element() {
let mut act = BitVec::from_elem(1, false);
assert!(act.eq_vec(&[false]));
assert!(act.none() && !act.all());
act = BitVec::from_elem(1, true);
assert!(act.eq_vec(&[true]));
assert!(!act.none() && act.all());
}
#[test]
fn test_2_elements() {
let mut b = BitVec::from_elem(2, false);
b.set(0, true);
b.set(1, false);
assert_eq!(format!("{:?}", b), "10");
assert!(!b.none() && !b.all());
}
#[test]
fn test_10_elements() {
let mut act;
// all 0
act = BitVec::from_elem(10, false);
assert!((act.eq_vec(
&[false, false, false, false, false, false, false, false, false, false])));
assert!(act.none() && !act.all());
// all 1
act = BitVec::from_elem(10, true);
assert!((act.eq_vec(&[true, true, true, true, true, true, true, true, true, true])));
assert!(!act.none() && act.all());
// mixed
act = BitVec::from_elem(10, false);
act.set(0, true);
act.set(1, true);
act.set(2, true);
act.set(3, true);
act.set(4, true);
assert!((act.eq_vec(&[true, true, true, true, true, false, false, false, false, false])));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(10, false);
act.set(5, true);
act.set(6, true);
act.set(7, true);
act.set(8, true);
act.set(9, true);
assert!((act.eq_vec(&[false, false, false, false, false, true, true, true, true, true])));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(10, false);
act.set(0, true);
act.set(3, true);
act.set(6, true);
act.set(9, true);
assert!((act.eq_vec(&[true, false, false, true, false, false, true, false, false, true])));
assert!(!act.none() && !act.all());
}
#[test]
fn test_31_elements() {
let mut act;
// all 0
act = BitVec::from_elem(31, false);
assert!(act.eq_vec(
&[false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false]));
assert!(act.none() && !act.all());
// all 1
act = BitVec::from_elem(31, true);
assert!(act.eq_vec(
&[true, true, true, true, true, true, true, true, true, true, true, true, true,
true, true, true, true, true, true, true, true, true, true, true, true, true,
true, true, true, true, true]));
assert!(!act.none() && act.all());
// mixed
act = BitVec::from_elem(31, false);
act.set(0, true);
act.set(1, true);
act.set(2, true);
act.set(3, true);
act.set(4, true);
act.set(5, true);
act.set(6, true);
act.set(7, true);
assert!(act.eq_vec(
&[true, true, true, true, true, true, true, true, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(31, false);
act.set(16, true);
act.set(17, true);
act.set(18, true);
act.set(19, true);
act.set(20, true);
act.set(21, true);
act.set(22, true);
act.set(23, true);
assert!(act.eq_vec(
&[false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, true, true, true, true, true, true, true, true,
false, false, false, false, false, false, false]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(31, false);
act.set(24, true);
act.set(25, true);
act.set(26, true);
act.set(27, true);
act.set(28, true);
act.set(29, true);
act.set(30, true);
assert!(act.eq_vec(
&[false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false,
false, false, true, true, true, true, true, true, true]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(31, false);
act.set(3, true);
act.set(17, true);
act.set(30, true);
assert!(act.eq_vec(
&[false, false, false, true, false, false, false, false, false, false, false, false,
false, false, false, false, false, true, false, false, false, false, false, false,
false, false, false, false, false, false, true]));
assert!(!act.none() && !act.all());
}
#[test]
fn test_32_elements() {
let mut act;
// all 0
act = BitVec::from_elem(32, false);
assert!(act.eq_vec(
&[false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false]));
assert!(act.none() && !act.all());
// all 1
act = BitVec::from_elem(32, true);
assert!(act.eq_vec(
&[true, true, true, true, true, true, true, true, true, true, true, true, true,
true, true, true, true, true, true, true, true, true, true, true, true, true,
true, true, true, true, true, true]));
assert!(!act.none() && act.all());
// mixed
act = BitVec::from_elem(32, false);
act.set(0, true);
act.set(1, true);
act.set(2, true);
act.set(3, true);
act.set(4, true);
act.set(5, true);
act.set(6, true);
act.set(7, true);
assert!(act.eq_vec(
&[true, true, true, true, true, true, true, true, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(32, false);
act.set(16, true);
act.set(17, true);
act.set(18, true);
act.set(19, true);
act.set(20, true);
act.set(21, true);
act.set(22, true);
act.set(23, true);
assert!(act.eq_vec(
&[false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, true, true, true, true, true, true, true, true,
false, false, false, false, false, false, false, false]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(32, false);
act.set(24, true);
act.set(25, true);
act.set(26, true);
act.set(27, true);
act.set(28, true);
act.set(29, true);
act.set(30, true);
act.set(31, true);
assert!(act.eq_vec(
&[false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false,
false, false, true, true, true, true, true, true, true, true]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(32, false);
act.set(3, true);
act.set(17, true);
act.set(30, true);
act.set(31, true);
assert!(act.eq_vec(
&[false, false, false, true, false, false, false, false, false, false, false, false,
false, false, false, false, false, true, false, false, false, false, false, false,
false, false, false, false, false, false, true, true]));
assert!(!act.none() && !act.all());
}
#[test]
fn test_33_elements() {
let mut act;
// all 0
act = BitVec::from_elem(33, false);
assert!(act.eq_vec(
&[false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false]));
assert!(act.none() && !act.all());
// all 1
act = BitVec::from_elem(33, true);
assert!(act.eq_vec(
&[true, true, true, true, true, true, true, true, true, true, true, true, true,
true, true, true, true, true, true, true, true, true, true, true, true, true,
true, true, true, true, true, true, true]));
assert!(!act.none() && act.all());
// mixed
act = BitVec::from_elem(33, false);
act.set(0, true);
act.set(1, true);
act.set(2, true);
act.set(3, true);
act.set(4, true);
act.set(5, true);
act.set(6, true);
act.set(7, true);
assert!(act.eq_vec(
&[true, true, true, true, true, true, true, true, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(33, false);
act.set(16, true);
act.set(17, true);
act.set(18, true);
act.set(19, true);
act.set(20, true);
act.set(21, true);
act.set(22, true);
act.set(23, true);
assert!(act.eq_vec(
&[false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, true, true, true, true, true, true, true, true,
false, false, false, false, false, false, false, false, false]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(33, false);
act.set(24, true);
act.set(25, true);
act.set(26, true);
act.set(27, true);
act.set(28, true);
act.set(29, true);
act.set(30, true);
act.set(31, true);
assert!(act.eq_vec(
&[false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false,
false, false, true, true, true, true, true, true, true, true, false]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(33, false);
act.set(3, true);
act.set(17, true);
act.set(30, true);
act.set(31, true);
act.set(32, true);
assert!(act.eq_vec(
&[false, false, false, true, false, false, false, false, false, false, false, false,
false, false, false, false, false, true, false, false, false, false, false, false,
false, false, false, false, false, false, true, true, true]));
assert!(!act.none() && !act.all());
}
#[test]
fn test_equal_differing_sizes() {
let v0 = BitVec::from_elem(10, false);
let v1 = BitVec::from_elem(11, false);
assert!(v0 != v1);
}
#[test]
fn test_equal_greatly_differing_sizes() {
let v0 = BitVec::from_elem(10, false);
let v1 = BitVec::from_elem(110, false);
assert!(v0 != v1);
}
#[test]
fn test_equal_sneaky_small() {
let mut a = BitVec::from_elem(1, false);
a.set(0, true);
let mut b = BitVec::from_elem(1, true);
b.set(0, true);
assert_eq!(a, b);
}
#[test]
fn test_equal_sneaky_big() {
let mut a = BitVec::from_elem(100, false);
for i in 0..100 {
a.set(i, true);
}
let mut b = BitVec::from_elem(100, true);
for i in 0..100 {
b.set(i, true);
}
assert_eq!(a, b);
}
#[test]
fn test_from_bytes() {
let bit_vec = BitVec::from_bytes(&[0b10110110, 0b00000000, 0b11111111]);
let str = concat!("10110110", "00000000", "11111111");
assert_eq!(format!("{:?}", bit_vec), str);
}
#[test]
fn test_to_bytes() {
let mut bv = BitVec::from_elem(3, true);
bv.set(1, false);
assert_eq!(bv.to_bytes(), [0b10100000]);
let mut bv = BitVec::from_elem(9, false);
bv.set(2, true);
bv.set(8, true);
assert_eq!(bv.to_bytes(), [0b00100000, 0b10000000]);
}
#[test]
fn test_from_bools() {
let bools = vec![true, false, true, true];
let bit_vec: BitVec = bools.iter().map(|n| *n).collect();
assert_eq!(format!("{:?}", bit_vec), "1011");
}
#[test]
fn test_to_bools() {
let bools = vec![false, false, true, false, false, true, true, false];
assert_eq!(BitVec::from_bytes(&[0b00100110]).iter().collect::<Vec<bool>>(), bools);
}
#[test]
fn test_bit_vec_iterator() {
let bools = vec![true, false, true, true];
let bit_vec: BitVec = bools.iter().map(|n| *n).collect();
assert_eq!(bit_vec.iter().collect::<Vec<bool>>(), bools);
let long: Vec<_> = (0i32..10000).map(|i| i % 2 == 0).collect();
let bit_vec: BitVec = long.iter().map(|n| *n).collect();
assert_eq!(bit_vec.iter().collect::<Vec<bool>>(), long)
}
#[test]
fn test_small_difference() {
let mut b1 = BitVec::from_elem(3, false);
let mut b2 = BitVec::from_elem(3, false);
b1.set(0, true);
b1.set(1, true);
b2.set(1, true);
b2.set(2, true);
assert!(b1.difference(&b2));
assert!(b1[0]);
assert!(!b1[1]);
assert!(!b1[2]);
}
#[test]
fn test_big_difference() {
let mut b1 = BitVec::from_elem(100, false);
let mut b2 = BitVec::from_elem(100, false);
b1.set(0, true);
b1.set(40, true);
b2.set(40, true);
b2.set(80, true);
assert!(b1.difference(&b2));
assert!(b1[0]);
assert!(!b1[40]);
assert!(!b1[80]);
}
#[test]
fn test_small_clear() {
let mut b = BitVec::from_elem(14, true);
assert!(!b.none() && b.all());
b.clear();
assert!(b.none() && !b.all());
}
#[test]
fn test_big_clear() {
let mut b = BitVec::from_elem(140, true);
assert!(!b.none() && b.all());
b.clear();
assert!(b.none() && !b.all());
}
#[test]
fn test_bit_vec_lt() {
let mut a = BitVec::from_elem(5, false);
let mut b = BitVec::from_elem(5, false);
assert!(!(a < b) && !(b < a));
b.set(2, true);
assert!(a < b);
a.set(3, true);
assert!(a < b);
a.set(2, true);
assert!(!(a < b) && b < a);
b.set(0, true);
assert!(a < b);
}
#[test]
fn test_ord() {
let mut a = BitVec::from_elem(5, false);
let mut b = BitVec::from_elem(5, false);
assert!(a <= b && a >= b);
a.set(1, true);
assert!(a > b && a >= b);
assert!(b < a && b <= a);
b.set(1, true);
b.set(2, true);
assert!(b > a && b >= a);
assert!(a < b && a <= b);
}
#[test]
fn test_small_bit_vec_tests() {
let v = BitVec::from_bytes(&[0]);
assert!(!v.all());
assert!(!v.any());
assert!(v.none());
let v = BitVec::from_bytes(&[0b00010100]);
assert!(!v.all());
assert!(v.any());
assert!(!v.none());
let v = BitVec::from_bytes(&[0xFF]);
assert!(v.all());
assert!(v.any());
assert!(!v.none());
}
#[test]
fn test_big_bit_vec_tests() {
let v = BitVec::from_bytes(&[ // 88 bits
0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0]);
assert!(!v.all());
assert!(!v.any());
assert!(v.none());
let v = BitVec::from_bytes(&[ // 88 bits
0, 0, 0b00010100, 0,
0, 0, 0, 0b00110100,
0, 0, 0]);
assert!(!v.all());
assert!(v.any());
assert!(!v.none());
let v = BitVec::from_bytes(&[ // 88 bits
0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF]);
assert!(v.all());
assert!(v.any());
assert!(!v.none());
}
#[test]
fn test_bit_vec_push_pop() {
let mut s = BitVec::from_elem(5 * u32::BITS as usize - 2, false);
assert_eq!(s.len(), 5 * u32::BITS as usize - 2);
assert_eq!(s[5 * u32::BITS as usize - 3], false);
s.push(true);
s.push(true);
assert_eq!(s[5 * u32::BITS as usize - 2], true);
assert_eq!(s[5 * u32::BITS as usize - 1], true);
// Here the internal vector will need to be extended
s.push(false);
assert_eq!(s[5 * u32::BITS as usize], false);
s.push(false);
assert_eq!(s[5 * u32::BITS as usize + 1], false);
assert_eq!(s.len(), 5 * u32::BITS as usize + 2);
// Pop it all off
assert_eq!(s.pop(), Some(false));
assert_eq!(s.pop(), Some(false));
assert_eq!(s.pop(), Some(true));
assert_eq!(s.pop(), Some(true));
assert_eq!(s.len(), 5 * u32::BITS as usize - 2);
}
#[test]
fn test_bit_vec_truncate() {
let mut s = BitVec::from_elem(5 * u32::BITS as usize, true);
assert_eq!(s, BitVec::from_elem(5 * u32::BITS as usize, true));
assert_eq!(s.len(), 5 * u32::BITS as usize);
s.truncate(4 * u32::BITS as usize);
assert_eq!(s, BitVec::from_elem(4 * u32::BITS as usize, true));
assert_eq!(s.len(), 4 * u32::BITS as usize);
// Truncating to a size > s.len() should be a noop
s.truncate(5 * u32::BITS as usize);
assert_eq!(s, BitVec::from_elem(4 * u32::BITS as usize, true));
assert_eq!(s.len(), 4 * u32::BITS as usize);
s.truncate(3 * u32::BITS as usize - 10);
assert_eq!(s, BitVec::from_elem(3 * u32::BITS as usize - 10, true));
assert_eq!(s.len(), 3 * u32::BITS as usize - 10);
s.truncate(0);
assert_eq!(s, BitVec::from_elem(0, true));
assert_eq!(s.len(), 0);
}
#[test]
fn test_bit_vec_reserve() {
let mut s = BitVec::from_elem(5 * u32::BITS as usize, true);
// Check capacity
assert!(s.capacity() >= 5 * u32::BITS as usize);
s.reserve(2 * u32::BITS as usize);
assert!(s.capacity() >= 7 * u32::BITS as usize);
s.reserve(7 * u32::BITS as usize);
assert!(s.capacity() >= 12 * u32::BITS as usize);
s.reserve_exact(7 * u32::BITS as usize);
assert!(s.capacity() >= 12 * u32::BITS as usize);
s.reserve(7 * u32::BITS as usize + 1);
assert!(s.capacity() >= 12 * u32::BITS as usize + 1);
// Check that length hasn't changed
assert_eq!(s.len(), 5 * u32::BITS as usize);
s.push(true);
s.push(false);
s.push(true);
assert_eq!(s[5 * u32::BITS as usize - 1], true);
assert_eq!(s[5 * u32::BITS as usize - 0], true);
assert_eq!(s[5 * u32::BITS as usize + 1], false);
assert_eq!(s[5 * u32::BITS as usize + 2], true);
}
#[test]
fn test_bit_vec_grow() {
let mut bit_vec = BitVec::from_bytes(&[0b10110110, 0b00000000, 0b10101010]);
bit_vec.grow(32, true);
assert_eq!(bit_vec, BitVec::from_bytes(&[0b10110110, 0b00000000, 0b10101010,
0xFF, 0xFF, 0xFF, 0xFF]));
bit_vec.grow(64, false);
assert_eq!(bit_vec, BitVec::from_bytes(&[0b10110110, 0b00000000, 0b10101010,
0xFF, 0xFF, 0xFF, 0xFF, 0, 0, 0, 0, 0, 0, 0, 0]));
bit_vec.grow(16, true);
assert_eq!(bit_vec, BitVec::from_bytes(&[0b10110110, 0b00000000, 0b10101010,
0xFF, 0xFF, 0xFF, 0xFF, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF]));
}
#[test]
fn test_bit_vec_extend() {
let mut bit_vec = BitVec::from_bytes(&[0b10110110, 0b00000000, 0b11111111]);
let ext = BitVec::from_bytes(&[0b01001001, 0b10010010, 0b10111101]);
bit_vec.extend(ext.iter());
assert_eq!(bit_vec, BitVec::from_bytes(&[0b10110110, 0b00000000, 0b11111111,
0b01001001, 0b10010010, 0b10111101]));
}
}
#[cfg(test)]
mod bit_vec_bench {
use std::prelude::v1::*;
use std::rand;
use std::rand::Rng;
use std::u32;
use test::{Bencher, black_box};
use super::BitVec;
static BENCH_BITS : usize = 1 << 14;
fn rng() -> rand::IsaacRng {
let seed: &[_] = &[1, 2, 3, 4, 5, 6, 7, 8, 9, 0];
rand::SeedableRng::from_seed(seed)
}
#[bench]
fn bench_usize_small(b: &mut Bencher) {
let mut r = rng();
let mut bit_vec = 0 as usize;
b.iter(|| {
for _ in 0..100 {
bit_vec |= 1 << ((r.next_u32() as usize) % u32::BITS as usize);
}
black_box(&bit_vec);
});
}
#[bench]
fn bench_bit_set_big_fixed(b: &mut Bencher) {
let mut r = rng();
let mut bit_vec = BitVec::from_elem(BENCH_BITS, false);
b.iter(|| {
for _ in 0..100 {
bit_vec.set((r.next_u32() as usize) % BENCH_BITS, true);
}
black_box(&bit_vec);
});
}
#[bench]
fn bench_bit_set_big_variable(b: &mut Bencher) {
let mut r = rng();
let mut bit_vec = BitVec::from_elem(BENCH_BITS, false);
b.iter(|| {
for _ in 0..100 {
bit_vec.set((r.next_u32() as usize) % BENCH_BITS, r.gen());
}
black_box(&bit_vec);
});
}
#[bench]
fn bench_bit_set_small(b: &mut Bencher) {
let mut r = rng();
let mut bit_vec = BitVec::from_elem(u32::BITS as usize, false);
b.iter(|| {
for _ in 0..100 {
bit_vec.set((r.next_u32() as usize) % u32::BITS as usize, true);
}
black_box(&bit_vec);
});
}
#[bench]
fn bench_bit_vec_big_union(b: &mut Bencher) {
let mut b1 = BitVec::from_elem(BENCH_BITS, false);
let b2 = BitVec::from_elem(BENCH_BITS, false);
b.iter(|| {
b1.union(&b2)
})
}
#[bench]
fn bench_bit_vec_small_iter(b: &mut Bencher) {
let bit_vec = BitVec::from_elem(u32::BITS as usize, false);
b.iter(|| {
let mut sum = 0;
for _ in 0..10 {
for pres in &bit_vec {
sum += pres as usize;
}
}
sum
})
}
#[bench]
fn bench_bit_vec_big_iter(b: &mut Bencher) {
let bit_vec = BitVec::from_elem(BENCH_BITS, false);
b.iter(|| {
let mut sum = 0;
for pres in &bit_vec {
sum += pres as usize;
}
sum
})
}
}
#[cfg(test)]
mod bit_set_test {
use prelude::*;
use std::iter::range_step;
use super::{BitVec, BitSet};
#[test]
fn test_bit_set_show() {
let mut s = BitSet::new();
s.insert(1);
s.insert(10);
s.insert(50);
s.insert(2);
assert_eq!("{1, 2, 10, 50}", format!("{:?}", s));
}
#[test]
fn test_bit_set_from_usizes() {
let usizes = vec![0, 2, 2, 3];
let a: BitSet = usizes.into_iter().collect();
let mut b = BitSet::new();
b.insert(0);
b.insert(2);
b.insert(3);
assert_eq!(a, b);
}
#[test]
fn test_bit_set_iterator() {
let usizes = vec![0, 2, 2, 3];
let bit_vec: BitSet = usizes.into_iter().collect();
let idxs: Vec<_> = bit_vec.iter().collect();
assert_eq!(idxs, [0, 2, 3]);
let long: BitSet = (0..10000).filter(|&n| n % 2 == 0).collect();
let real: Vec<_> = range_step(0, 10000, 2).collect();
let idxs: Vec<_> = long.iter().collect();
assert_eq!(idxs, real);
}
#[test]
fn test_bit_set_frombit_vec_init() {
let bools = [true, false];
let lengths = [10, 64, 100];
for &b in &bools {
for &l in &lengths {
let bitset = BitSet::from_bit_vec(BitVec::from_elem(l, b));
assert_eq!(bitset.contains(&1), b);
assert_eq!(bitset.contains(&(l-1)), b);
assert!(!bitset.contains(&l));
}
}
}
#[test]
fn test_bit_vec_masking() {
let b = BitVec::from_elem(140, true);
let mut bs = BitSet::from_bit_vec(b);
assert!(bs.contains(&139));
assert!(!bs.contains(&140));
assert!(bs.insert(150));
assert!(!bs.contains(&140));
assert!(!bs.contains(&149));
assert!(bs.contains(&150));
assert!(!bs.contains(&151));
}
#[test]
fn test_bit_set_basic() {
let mut b = BitSet::new();
assert!(b.insert(3));
assert!(!b.insert(3));
assert!(b.contains(&3));
assert!(b.insert(4));
assert!(!b.insert(4));
assert!(b.contains(&3));
assert!(b.insert(400));
assert!(!b.insert(400));
assert!(b.contains(&400));
assert_eq!(b.len(), 3);
}
#[test]
fn test_bit_set_intersection() {
let mut a = BitSet::new();
let mut b = BitSet::new();
assert!(a.insert(11));
assert!(a.insert(1));
assert!(a.insert(3));
assert!(a.insert(77));
assert!(a.insert(103));
assert!(a.insert(5));
assert!(b.insert(2));
assert!(b.insert(11));
assert!(b.insert(77));
assert!(b.insert(5));
assert!(b.insert(3));
let expected = [3, 5, 11, 77];
let actual: Vec<_> = a.intersection(&b).collect();
assert_eq!(actual, expected);
}
#[test]
fn test_bit_set_difference() {
let mut a = BitSet::new();
let mut b = BitSet::new();
assert!(a.insert(1));
assert!(a.insert(3));
assert!(a.insert(5));
assert!(a.insert(200));
assert!(a.insert(500));
assert!(b.insert(3));
assert!(b.insert(200));
let expected = [1, 5, 500];
let actual: Vec<_> = a.difference(&b).collect();
assert_eq!(actual, expected);
}
#[test]
fn test_bit_set_symmetric_difference() {
let mut a = BitSet::new();
let mut b = BitSet::new();
assert!(a.insert(1));
assert!(a.insert(3));
assert!(a.insert(5));
assert!(a.insert(9));
assert!(a.insert(11));
assert!(b.insert(3));
assert!(b.insert(9));
assert!(b.insert(14));
assert!(b.insert(220));
let expected = [1, 5, 11, 14, 220];
let actual: Vec<_> = a.symmetric_difference(&b).collect();
assert_eq!(actual, expected);
}
#[test]
fn test_bit_set_union() {
let mut a = BitSet::new();
let mut b = BitSet::new();
assert!(a.insert(1));
assert!(a.insert(3));
assert!(a.insert(5));
assert!(a.insert(9));
assert!(a.insert(11));
assert!(a.insert(160));
assert!(a.insert(19));
assert!(a.insert(24));
assert!(a.insert(200));
assert!(b.insert(1));
assert!(b.insert(5));
assert!(b.insert(9));
assert!(b.insert(13));
assert!(b.insert(19));
let expected = [1, 3, 5, 9, 11, 13, 19, 24, 160, 200];
let actual: Vec<_> = a.union(&b).collect();
assert_eq!(actual, expected);
}
#[test]
fn test_bit_set_subset() {
let mut set1 = BitSet::new();
let mut set2 = BitSet::new();
assert!(set1.is_subset(&set2)); // {} {}
set2.insert(100);
assert!(set1.is_subset(&set2)); // {} { 1 }
set2.insert(200);
assert!(set1.is_subset(&set2)); // {} { 1, 2 }
set1.insert(200);
assert!(set1.is_subset(&set2)); // { 2 } { 1, 2 }
set1.insert(300);
assert!(!set1.is_subset(&set2)); // { 2, 3 } { 1, 2 }
set2.insert(300);
assert!(set1.is_subset(&set2)); // { 2, 3 } { 1, 2, 3 }
set2.insert(400);
assert!(set1.is_subset(&set2)); // { 2, 3 } { 1, 2, 3, 4 }
set2.remove(&100);
assert!(set1.is_subset(&set2)); // { 2, 3 } { 2, 3, 4 }
set2.remove(&300);
assert!(!set1.is_subset(&set2)); // { 2, 3 } { 2, 4 }
set1.remove(&300);
assert!(set1.is_subset(&set2)); // { 2 } { 2, 4 }
}
#[test]
fn test_bit_set_is_disjoint() {
let a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01000000]));
let c = BitSet::new();
let d = BitSet::from_bit_vec(BitVec::from_bytes(&[0b00110000]));
assert!(!a.is_disjoint(&d));
assert!(!d.is_disjoint(&a));
assert!(a.is_disjoint(&b));
assert!(a.is_disjoint(&c));
assert!(b.is_disjoint(&a));
assert!(b.is_disjoint(&c));
assert!(c.is_disjoint(&a));
assert!(c.is_disjoint(&b));
}
#[test]
fn test_bit_set_union_with() {
//a should grow to include larger elements
let mut a = BitSet::new();
a.insert(0);
let mut b = BitSet::new();
b.insert(5);
let expected = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10000100]));
a.union_with(&b);
assert_eq!(a, expected);
// Standard
let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
let mut b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01100010]));
let c = a.clone();
a.union_with(&b);
b.union_with(&c);
assert_eq!(a.len(), 4);
assert_eq!(b.len(), 4);
}
#[test]
fn test_bit_set_intersect_with() {
// Explicitly 0'ed bits
let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
let mut b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b00000000]));
let c = a.clone();
a.intersect_with(&b);
b.intersect_with(&c);
assert!(a.is_empty());
assert!(b.is_empty());
// Uninitialized bits should behave like 0's
let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
let mut b = BitSet::new();
let c = a.clone();
a.intersect_with(&b);
b.intersect_with(&c);
assert!(a.is_empty());
assert!(b.is_empty());
// Standard
let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
let mut b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01100010]));
let c = a.clone();
a.intersect_with(&b);
b.intersect_with(&c);
assert_eq!(a.len(), 2);
assert_eq!(b.len(), 2);
}
#[test]
fn test_bit_set_difference_with() {
// Explicitly 0'ed bits
let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b00000000]));
let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
a.difference_with(&b);
assert!(a.is_empty());
// Uninitialized bits should behave like 0's
let mut a = BitSet::new();
let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b11111111]));
a.difference_with(&b);
assert!(a.is_empty());
// Standard
let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
let mut b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01100010]));
let c = a.clone();
a.difference_with(&b);
b.difference_with(&c);
assert_eq!(a.len(), 1);
assert_eq!(b.len(), 1);
}
#[test]
fn test_bit_set_symmetric_difference_with() {
//a should grow to include larger elements
let mut a = BitSet::new();
a.insert(0);
a.insert(1);
let mut b = BitSet::new();
b.insert(1);
b.insert(5);
let expected = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10000100]));
a.symmetric_difference_with(&b);
assert_eq!(a, expected);
let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
let b = BitSet::new();
let c = a.clone();
a.symmetric_difference_with(&b);
assert_eq!(a, c);
// Standard
let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b11100010]));
let mut b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01101010]));
let c = a.clone();
a.symmetric_difference_with(&b);
b.symmetric_difference_with(&c);
assert_eq!(a.len(), 2);
assert_eq!(b.len(), 2);
}
#[test]
fn test_bit_set_eq() {
let a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b00000000]));
let c = BitSet::new();
assert!(a == a);
assert!(a != b);
assert!(a != c);
assert!(b == b);
assert!(b == c);
assert!(c == c);
}
#[test]
fn test_bit_set_cmp() {
let a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b00000000]));
let c = BitSet::new();
assert_eq!(a.cmp(&b), Greater);
assert_eq!(a.cmp(&c), Greater);
assert_eq!(b.cmp(&a), Less);
assert_eq!(b.cmp(&c), Equal);
assert_eq!(c.cmp(&a), Less);
assert_eq!(c.cmp(&b), Equal);
}
#[test]
fn test_bit_vec_remove() {
let mut a = BitSet::new();
assert!(a.insert(1));
assert!(a.remove(&1));
assert!(a.insert(100));
assert!(a.remove(&100));
assert!(a.insert(1000));
assert!(a.remove(&1000));
a.shrink_to_fit();
}
#[test]
fn test_bit_vec_clone() {
let mut a = BitSet::new();
assert!(a.insert(1));
assert!(a.insert(100));
assert!(a.insert(1000));
let mut b = a.clone();
assert!(a == b);
assert!(b.remove(&1));
assert!(a.contains(&1));
assert!(a.remove(&1000));
assert!(b.contains(&1000));
}
}
#[cfg(test)]
mod bit_set_bench {
use std::prelude::v1::*;
use std::rand;
use std::rand::Rng;
use std::u32;
use test::{Bencher, black_box};
use super::{BitVec, BitSet};
static BENCH_BITS : usize = 1 << 14;
fn rng() -> rand::IsaacRng {
let seed: &[_] = &[1, 2, 3, 4, 5, 6, 7, 8, 9, 0];
rand::SeedableRng::from_seed(seed)
}
#[bench]
fn bench_bit_vecset_small(b: &mut Bencher) {
let mut r = rng();
let mut bit_vec = BitSet::new();
b.iter(|| {
for _ in 0..100 {
bit_vec.insert((r.next_u32() as usize) % u32::BITS as usize);
}
black_box(&bit_vec);
});
}
#[bench]
fn bench_bit_vecset_big(b: &mut Bencher) {
let mut r = rng();
let mut bit_vec = BitSet::new();
b.iter(|| {
for _ in 0..100 {
bit_vec.insert((r.next_u32() as usize) % BENCH_BITS);
}
black_box(&bit_vec);
});
}
#[bench]
fn bench_bit_vecset_iter(b: &mut Bencher) {
let bit_vec = BitSet::from_bit_vec(BitVec::from_fn(BENCH_BITS,
|idx| {idx % 3 == 0}));
b.iter(|| {
let mut sum = 0;
for idx in &bit_vec {
sum += idx as usize;
}
sum
})
}
}
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