2501 lines
71 KiB
Rust

// 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.
//! Collections implemented with bit vectors.
//!
//! # Example
//!
//! 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::{BitvSet, Bitv};
//! use std::iter;
//!
//! let max_prime = 10000;
//!
//! // Store the primes as a BitvSet
//! let primes = {
//! // Assume all numbers are prime to begin, and then we
//! // cross off non-primes progressively
//! let mut bv = Bitv::with_capacity(max_prime, true);
//!
//! // Neither 0 nor 1 are prime
//! bv.set(0, false);
//! bv.set(1, false);
//!
//! for i in range(2, max_prime) {
//! // 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) }
//! }
//! }
//! BitvSet::from_bitv(bv)
//! };
//!
//! // Simple primality tests below our max bound
//! let print_primes = 20;
//! print!("The primes below {} are: ", print_primes);
//! for x in range(0, print_primes) {
//! if primes.contains(&x) {
//! print!("{} ", x);
//! }
//! }
//! println!("");
//!
//! // We can manipulate the internal Bitv
//! let num_primes = primes.get_ref().iter().filter(|x| *x).count();
//! println!("There are {} primes below {}", num_primes, max_prime);
//! ```
#![allow(missing_doc)]
use core::prelude::*;
use core::cmp;
use core::default::Default;
use core::fmt;
use core::iter::Take;
use core::iter;
use core::ops::Index;
use core::slice;
use core::uint;
use std::hash;
use {Collection, Mutable, Set, MutableSet, MutableSeq};
use vec::Vec;
static TRUE: bool = true;
static FALSE: bool = false;
#[deriving(Clone)]
struct SmallBitv {
/// only the lowest nbits of this value are used. the rest is undefined.
bits: uint
}
#[deriving(Clone)]
struct BigBitv {
storage: Vec<uint>
}
#[deriving(Clone)]
enum BitvVariant { Big(BigBitv), Small(SmallBitv) }
/// The bitvector type
///
/// # Example
///
/// ```rust
/// use collections::Bitv;
///
/// let mut bv = Bitv::with_capacity(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.to_string());
/// 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.to_string());
/// println!("total bits set to true: {}", bv.iter().filter(|x| *x).count());
///
/// // reset bitvector to empty
/// bv.clear();
/// println!("{}", bv.to_string());
/// println!("total bits set to true: {}", bv.iter().filter(|x| *x).count());
/// ```
pub struct Bitv {
/// Internal representation of the bit vector
storage: Vec<uint>,
/// The number of valid bits in the internal representation
nbits: uint
}
impl Index<uint,bool> for Bitv {
#[inline]
fn index<'a>(&'a self, i: &uint) -> &'a bool {
if self.get(*i) {
&TRUE
} else {
&FALSE
}
}
}
struct MaskWords<'a> {
iter: slice::Items<'a, uint>,
next_word: Option<&'a uint>,
last_word_mask: uint,
offset: uint
}
impl<'a> Iterator<(uint, uint)> for MaskWords<'a> {
/// Returns (offset, word)
#[inline]
fn next<'a>(&'a mut self) -> Option<(uint, uint)> {
let ret = self.next_word;
match ret {
Some(&w) => {
self.next_word = self.iter.next();
self.offset += 1;
// The last word may need to be masked
if self.next_word.is_none() {
Some((self.offset - 1, w & self.last_word_mask))
} else {
Some((self.offset - 1, w))
}
},
None => None
}
}
}
impl Bitv {
#[inline]
fn process(&mut self, other: &Bitv, op: |uint, uint| -> uint) -> bool {
let len = other.storage.len();
assert_eq!(self.storage.len(), len);
let mut changed = false;
// Notice: `a` is *not* masked here, which is fine as long as
// `op` is a bitwise operation, since any bits that should've
// been masked were fine to change anyway. `b` is masked to
// make sure its unmasked bits do not cause damage.
for (a, (_, b)) in self.storage.mut_iter()
.zip(other.mask_words(0)) {
let w = op(*a, b);
if *a != w {
changed = true;
*a = w;
}
}
changed
}
#[inline]
fn mask_words<'a>(&'a self, mut start: uint) -> MaskWords<'a> {
if start > self.storage.len() {
start = self.storage.len();
}
let mut iter = self.storage.slice_from(start).iter();
MaskWords {
next_word: iter.next(),
iter: iter,
last_word_mask: {
let rem = self.nbits % uint::BITS;
if rem > 0 {
(1 << rem) - 1
} else { !0 }
},
offset: start
}
}
/// Create an empty Bitv.
///
/// # Example
///
/// ```
/// use std::collections::Bitv;
/// let mut bv = Bitv::new();
/// ```
pub fn new() -> Bitv {
Bitv { storage: Vec::new(), nbits: 0 }
}
/// Create a Bitv that holds `nbits` elements, setting each element
/// to `init`.
///
/// # Example
///
/// ```
/// use std::collections::Bitv;
///
/// let mut bv = Bitv::with_capacity(10u, false);
/// assert_eq!(bv.len(), 10u);
/// for x in bv.iter() {
/// assert_eq!(x, false);
/// }
/// ```
pub fn with_capacity(nbits: uint, init: bool) -> Bitv {
Bitv {
storage: Vec::from_elem((nbits + uint::BITS - 1) / uint::BITS,
if init { !0u } else { 0u }),
nbits: nbits
}
}
/// Retrieve the value at index `i`.
///
/// # Failure
///
/// Assert if `i` out of bounds.
///
/// # Example
///
/// ```
/// use std::collections::bitv;
///
/// let bv = bitv::from_bytes([0b01100000]);
/// assert_eq!(bv.get(0), false);
/// assert_eq!(bv.get(1), true);
///
/// // Can also use array indexing
/// assert_eq!(bv[1], true);
/// ```
#[inline]
pub fn get(&self, i: uint) -> bool {
assert!(i < self.nbits);
let w = i / uint::BITS;
let b = i % uint::BITS;
let x = self.storage.get(w) & (1 << b);
x != 0
}
/// Set the value of a bit at a index `i`.
///
/// # Failure
///
/// Assert if `i` out of bounds.
///
/// # Example
///
/// ```
/// use std::collections::Bitv;
///
/// let mut bv = Bitv::with_capacity(5, false);
/// bv.set(3, true);
/// assert_eq!(bv[3], true);
/// ```
#[inline]
pub fn set(&mut self, i: uint, x: bool) {
assert!(i < self.nbits);
let w = i / uint::BITS;
let b = i % uint::BITS;
let flag = 1 << b;
*self.storage.get_mut(w) = if x { *self.storage.get(w) | flag }
else { *self.storage.get(w) & !flag };
}
/// Set all bits to 1.
///
/// # Example
///
/// ```
/// use std::collections::bitv;
///
/// let before = 0b01100000;
/// let after = 0b11111111;
///
/// let mut bv = bitv::from_bytes([before]);
/// bv.set_all();
/// assert_eq!(bv, bitv::from_bytes([after]));
/// ```
#[inline]
pub fn set_all(&mut self) {
for w in self.storage.mut_iter() { *w = !0u; }
}
/// Flip all bits.
///
/// # Example
///
/// ```
/// use std::collections::bitv;
///
/// let before = 0b01100000;
/// let after = 0b10011111;
///
/// let mut bv = bitv::from_bytes([before]);
/// bv.negate();
/// assert_eq!(bv, bitv::from_bytes([after]));
/// ```
#[inline]
pub fn negate(&mut self) {
for w in self.storage.mut_iter() { *w = !*w; }
}
/// Calculate the union of two bitvectors, acts like bitwise or.
///
/// Set `self` to the union of `self` and `other`. Both bitvectors must be
/// the same length. Return `true` if `self` changed.
///
/// # Failure
///
/// Assert if the bitvectors are of different length.
///
/// # Example
///
/// ```
/// use std::collections::bitv;
///
/// let a = 0b01100100;
/// let b = 0b01011010;
/// let res = 0b01111110;
///
/// let mut a = bitv::from_bytes([a]);
/// let b = bitv::from_bytes([b]);
///
/// assert!(a.union(&b));
/// assert_eq!(a, bitv::from_bytes([res]));
/// ```
#[inline]
pub fn union(&mut self, other: &Bitv) -> bool {
self.process(other, |w1, w2| w1 | w2)
}
/// Calculate the intersection of two bitvectors, acts like bitwise and.
///
/// Set `self` to the intersection of `self` and `other`. Both bitvectors
/// must be the same length. Return `true` if `self` changed.
///
/// # Failure
///
/// Assert if the bitvectors are of different length.
///
/// # Example
///
/// ```
/// use std::collections::bitv;
///
/// let a = 0b01100100;
/// let b = 0b01011010;
/// let res = 0b01000000;
///
/// let mut a = bitv::from_bytes([a]);
/// let b = bitv::from_bytes([b]);
///
/// assert!(a.intersect(&b));
/// assert_eq!(a, bitv::from_bytes([res]));
/// ```
#[inline]
pub fn intersect(&mut self, other: &Bitv) -> bool {
self.process(other, |w1, w2| w1 & w2)
}
/// Calculate the difference between two bitvectors.
///
/// Set 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. Return `true` if `self` changed.
///
/// # Failure
///
/// Assert if the bitvectors are of different length.
///
/// # Example
///
/// ```
/// use std::collections::bitv;
///
/// let a = 0b01100100;
/// let b = 0b01011010;
/// let a_b = 0b00100100; // a - b
/// let b_a = 0b00011010; // b - a
///
/// let mut bva = bitv::from_bytes([a]);
/// let bvb = bitv::from_bytes([b]);
///
/// assert!(bva.difference(&bvb));
/// assert_eq!(bva, bitv::from_bytes([a_b]));
///
/// let bva = bitv::from_bytes([a]);
/// let mut bvb = bitv::from_bytes([b]);
///
/// assert!(bvb.difference(&bva));
/// assert_eq!(bvb, bitv::from_bytes([b_a]));
/// ```
#[inline]
pub fn difference(&mut self, other: &Bitv) -> bool {
self.process(other, |w1, w2| w1 & !w2)
}
/// Returns `true` if all bits are 1.
///
/// # Example
///
/// ```
/// use std::collections::Bitv;
///
/// let mut bv = Bitv::with_capacity(5, true);
/// assert_eq!(bv.all(), true);
///
/// bv.set(1, false);
/// assert_eq!(bv.all(), false);
/// ```
#[inline]
pub fn all(&self) -> bool {
let mut last_word = !0u;
// Check that every word but the last is all-ones...
self.mask_words(0).all(|(_, elem)|
{ let tmp = last_word; last_word = elem; tmp == !0u }) &&
// ...and that the last word is ones as far as it needs to be
(last_word == ((1 << self.nbits % uint::BITS) - 1) || last_word == !0u)
}
/// Return an iterator over the elements of the vector in order.
///
/// # Example
///
/// ```
/// use std::collections::bitv;
///
/// let bv = bitv::from_bytes([0b01110100, 0b10010010]);
/// assert_eq!(bv.iter().filter(|x| *x).count(), 7);
/// ```
#[inline]
pub fn iter<'a>(&'a self) -> Bits<'a> {
Bits {bitv: self, next_idx: 0, end_idx: self.nbits}
}
/// Return `true` if all bits are 0.
///
/// # Example
///
/// ```
/// use std::collections::Bitv;
///
/// let mut bv = Bitv::with_capacity(10, false);
/// assert_eq!(bv.none(), true);
///
/// bv.set(3, true);
/// assert_eq!(bv.none(), false);
/// ```
pub fn none(&self) -> bool {
self.mask_words(0).all(|(_, w)| w == 0)
}
/// Return `true` if any bit is 1.
///
/// # Example
///
/// ```
/// use std::collections::Bitv;
///
/// let mut bv = Bitv::with_capacity(10, false);
/// assert_eq!(bv.any(), false);
///
/// bv.set(3, true);
/// assert_eq!(bv.any(), true);
/// ```
#[inline]
pub fn any(&self) -> bool {
!self.none()
}
/// Organise the bits into bytes, such that the first bit in the
/// `Bitv` becomes the high-order bit of the first byte. If the
/// size of the `Bitv` is not a multiple of 8 then trailing bits
/// will be filled-in with `false`.
///
/// # Example
///
/// ```
/// use std::collections::Bitv;
///
/// let mut bv = Bitv::with_capacity(3, true);
/// bv.set(1, false);
///
/// assert_eq!(bv.to_bytes(), vec!(0b10100000));
///
/// let mut bv = Bitv::with_capacity(9, false);
/// bv.set(2, true);
/// bv.set(8, true);
///
/// assert_eq!(bv.to_bytes(), vec!(0b00100000, 0b10000000));
/// ```
pub fn to_bytes(&self) -> Vec<u8> {
fn bit (bitv: &Bitv, byte: uint, bit: uint) -> u8 {
let offset = byte * 8 + bit;
if offset >= bitv.nbits {
0
} else {
bitv.get(offset) as u8 << (7 - bit)
}
}
let len = self.nbits/8 +
if self.nbits % 8 == 0 { 0 } else { 1 };
Vec::from_fn(len, |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)
)
}
/// Transform `self` into a `Vec<bool>` by turning each bit into a `bool`.
///
/// # Example
///
/// ```
/// use std::collections::bitv;
///
/// let bv = bitv::from_bytes([0b10100000]);
/// assert_eq!(bv.to_bools(), vec!(true, false, true, false,
/// false, false, false, false));
/// ```
pub fn to_bools(&self) -> Vec<bool> {
Vec::from_fn(self.nbits, |i| self.get(i))
}
/// Compare a bitvector to a vector of `bool`.
/// Both the bitvector and vector must have the same length.
/// # Failure
///
/// Assert if the bitvectors are of different length.
///
/// # Example
///
/// ```
/// use std::collections::bitv;
///
/// let bv = bitv::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());
let mut i = 0;
while i < self.nbits {
if self.get(i) != v[i] { return false; }
i = i + 1;
}
true
}
/// Shorten a Bitv, dropping excess elements.
///
/// If `len` is greater than the vector's current length, this has no
/// effect.
///
/// # Example
///
/// ```
/// use std::collections::bitv;
///
/// let mut bv = bitv::from_bytes([0b01001011]);
/// bv.truncate(2);
/// assert!(bv.eq_vec([false, true]));
/// ```
pub fn truncate(&mut self, len: uint) {
if len < self.len() {
self.nbits = len;
let word_len = (len + uint::BITS - 1) / uint::BITS;
self.storage.truncate(word_len);
if len % uint::BITS > 0 {
let mask = (1 << len % uint::BITS) - 1;
*self.storage.get_mut(word_len - 1) &= mask;
}
}
}
/// Grow the vector to be able to store `size` bits without resizing.
///
/// # Example
///
/// ```
/// use std::collections::Bitv;
///
/// let mut bv = Bitv::with_capacity(3, false);
/// bv.reserve(10);
/// assert_eq!(bv.len(), 3);
/// assert!(bv.capacity() >= 10);
/// ```
pub fn reserve(&mut self, size: uint) {
let old_size = self.storage.len();
let size = (size + uint::BITS - 1) / uint::BITS;
if old_size < size {
self.storage.grow(size - old_size, &0);
}
}
/// Return the capacity in bits for this bit vector. Inserting any
/// element less than this amount will not trigger a resizing.
///
/// # Example
///
/// ```
/// use std::collections::Bitv;
///
/// let mut bv = Bitv::new();
/// bv.reserve(10);
/// assert!(bv.capacity() >= 10);
/// ```
#[inline]
pub fn capacity(&self) -> uint {
self.storage.len() * uint::BITS
}
/// Grow the `Bitv` in-place. Add `n` copies of `value` to the `Bitv`.
///
/// # Example
///
/// ```
/// use std::collections::bitv;
///
/// let mut bv = bitv::from_bytes([0b01001011]);
/// bv.grow(2, true);
/// assert_eq!(bv.len(), 10);
/// assert_eq!(bv.to_bytes(), vec!(0b01001011, 0b11000000));
/// ```
pub fn grow(&mut self, n: uint, value: bool) {
let new_nbits = self.nbits + n;
let new_nwords = (new_nbits + uint::BITS - 1) / uint::BITS;
let full_value = if value { !0 } else { 0 };
// Correct the old tail word
let old_last_word = (self.nbits + uint::BITS - 1) / uint::BITS - 1;
if self.nbits % uint::BITS > 0 {
let overhang = self.nbits % uint::BITS; // # of already-used bits
let mask = !((1 << overhang) - 1); // e.g. 5 unused bits => 111110....0
if value {
*self.storage.get_mut(old_last_word) |= mask;
} else {
*self.storage.get_mut(old_last_word) &= !mask;
}
}
// Fill in words after the old tail word
let stop_idx = cmp::min(self.storage.len(), new_nwords);
for idx in range(old_last_word + 1, stop_idx) {
*self.storage.get_mut(idx) = full_value;
}
// Allocate new words, if needed
if new_nwords > self.storage.len() {
let to_add = new_nwords - self.storage.len();
self.storage.grow(to_add, &full_value);
}
// Adjust internal bit count
self.nbits = new_nbits;
}
/// Shorten by one and return the removed element.
///
/// # Failure
///
/// Assert if empty.
///
/// # Example
///
/// ```
/// use std::collections::bitv;
///
/// let mut bv = bitv::from_bytes([0b01001001]);
/// assert_eq!(bv.pop(), true);
/// assert_eq!(bv.pop(), false);
/// assert_eq!(bv.len(), 6);
/// assert_eq!(bv.to_bytes(), vec!(0b01001000));
/// ```
pub fn pop(&mut self) -> bool {
let ret = self.get(self.nbits - 1);
// If we are unusing a whole word, make sure it is zeroed out
if self.nbits % uint::BITS == 1 {
*self.storage.get_mut(self.nbits / uint::BITS) = 0;
}
self.nbits -= 1;
ret
}
/// Push a `bool` onto the end.
///
/// # Example
///
/// ```
/// use std::collections::Bitv;
///
/// let mut bv = Bitv::new();
/// bv.push(true);
/// bv.push(false);
/// assert!(bv.eq_vec([true, false]));
/// ```
pub fn push(&mut self, elem: bool) {
let insert_pos = self.nbits;
self.nbits += 1;
if self.storage.len() * uint::BITS < self.nbits {
self.storage.push(0);
}
self.set(insert_pos, elem);
}
}
/// Transform a byte-vector into a `Bitv`. Each byte becomes 8 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.
///
/// # Example
///
/// ```
/// use std::collections::bitv;
///
/// let bv = bitv::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]) -> Bitv {
from_fn(bytes.len() * 8, |i| {
let b = bytes[i / 8] as uint;
let offset = i % 8;
b >> (7 - offset) & 1 == 1
})
}
/// Create a `Bitv` of the specified length where the value at each
/// index is `f(index)`.
///
/// # Example
///
/// ```
/// use std::collections::bitv::from_fn;
///
/// let bv = from_fn(5, |i| { i % 2 == 0 });
/// assert!(bv.eq_vec([true, false, true, false, true]));
/// ```
pub fn from_fn(len: uint, f: |index: uint| -> bool) -> Bitv {
let mut bitv = Bitv::with_capacity(len, false);
for i in range(0u, len) {
bitv.set(i, f(i));
}
bitv
}
impl Default for Bitv {
#[inline]
fn default() -> Bitv { Bitv::new() }
}
impl Collection for Bitv {
#[inline]
fn len(&self) -> uint { self.nbits }
}
impl Mutable for Bitv {
#[inline]
fn clear(&mut self) {
for w in self.storage.mut_iter() { *w = 0u; }
}
}
impl FromIterator<bool> for Bitv {
fn from_iter<I:Iterator<bool>>(iterator: I) -> Bitv {
let mut ret = Bitv::new();
ret.extend(iterator);
ret
}
}
impl Extendable<bool> for Bitv {
#[inline]
fn extend<I: Iterator<bool>>(&mut self, mut iterator: I) {
let (min, _) = iterator.size_hint();
let nbits = self.nbits;
self.reserve(nbits + min);
for element in iterator {
self.push(element)
}
}
}
impl Clone for Bitv {
#[inline]
fn clone(&self) -> Bitv {
Bitv { storage: self.storage.clone(), nbits: self.nbits }
}
#[inline]
fn clone_from(&mut self, source: &Bitv) {
self.nbits = source.nbits;
self.storage.reserve(source.storage.len());
for (i, w) in self.storage.mut_iter().enumerate() { *w = *source.storage.get(i); }
}
}
impl PartialOrd for Bitv {
#[inline]
fn partial_cmp(&self, other: &Bitv) -> Option<Ordering> {
iter::order::partial_cmp(self.iter(), other.iter())
}
}
impl Ord for Bitv {
#[inline]
fn cmp(&self, other: &Bitv) -> Ordering {
iter::order::cmp(self.iter(), other.iter())
}
}
impl fmt::Show for Bitv {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
for bit in self.iter() {
try!(write!(fmt, "{}", if bit { 1u } else { 0u }));
}
Ok(())
}
}
impl<S: hash::Writer> hash::Hash<S> for Bitv {
fn hash(&self, state: &mut S) {
self.nbits.hash(state);
for (_, elem) in self.mask_words(0) {
elem.hash(state);
}
}
}
impl cmp::PartialEq for Bitv {
#[inline]
fn eq(&self, other: &Bitv) -> bool {
if self.nbits != other.nbits {
return false;
}
self.mask_words(0).zip(other.mask_words(0)).all(|((_, w1), (_, w2))| w1 == w2)
}
}
impl cmp::Eq for Bitv {}
/// An iterator for `Bitv`.
pub struct Bits<'a> {
bitv: &'a Bitv,
next_idx: uint,
end_idx: uint,
}
impl<'a> Iterator<bool> for Bits<'a> {
#[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.bitv.get(idx))
} else {
None
}
}
fn size_hint(&self) -> (uint, Option<uint>) {
let rem = self.end_idx - self.next_idx;
(rem, Some(rem))
}
}
impl<'a> DoubleEndedIterator<bool> for Bits<'a> {
#[inline]
fn next_back(&mut self) -> Option<bool> {
if self.next_idx != self.end_idx {
self.end_idx -= 1;
Some(self.bitv.get(self.end_idx))
} else {
None
}
}
}
impl<'a> ExactSize<bool> for Bits<'a> {}
impl<'a> RandomAccessIterator<bool> for Bits<'a> {
#[inline]
fn indexable(&self) -> uint {
self.end_idx - self.next_idx
}
#[inline]
fn idx(&mut self, index: uint) -> Option<bool> {
if index >= self.indexable() {
None
} else {
Some(self.bitv.get(index))
}
}
}
/// 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 `uint`.
///
/// # Example
///
/// ```
/// use std::collections::{BitvSet, Bitv};
/// use std::collections::bitv;
///
/// // It's a regular set
/// let mut s = BitvSet::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 `Bitv`
/// let other = BitvSet::from_bitv(bitv::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 `Bitv`
/// let bv: Bitv = s.unwrap();
/// assert!(bv.eq_vec([true, true, false, true,
/// false, false, false, false]));
/// ```
#[deriving(Clone, PartialEq, Eq, PartialOrd, Ord)]
pub struct BitvSet(Bitv);
impl Default for BitvSet {
#[inline]
fn default() -> BitvSet { BitvSet::new() }
}
impl BitvSet {
/// Create a new bit vector set with initially no contents.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
/// let mut s = BitvSet::new();
/// ```
#[inline]
pub fn new() -> BitvSet {
BitvSet(Bitv::new())
}
/// Create a new bit vector set with initially no contents, able to
/// hold `nbits` elements without resizing.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
/// let mut s = BitvSet::with_capacity(100);
/// assert!(s.capacity() >= 100);
/// ```
#[inline]
pub fn with_capacity(nbits: uint) -> BitvSet {
BitvSet(Bitv::with_capacity(nbits, false))
}
/// Create a new bit vector set from the given bit vector.
///
/// # Example
///
/// ```
/// use std::collections::{bitv, BitvSet};
///
/// let bv = bitv::from_bytes([0b01100000]);
/// let s = BitvSet::from_bitv(bv);
///
/// // Print 1, 2 in arbitrary order
/// for x in s.iter() {
/// println!("{}", x);
/// }
/// ```
#[inline]
pub fn from_bitv(bitv: Bitv) -> BitvSet {
BitvSet(bitv)
}
/// Returns the capacity in bits for this bit vector. Inserting any
/// element less than this amount will not trigger a resizing.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
///
/// let mut s = BitvSet::with_capacity(100);
/// assert!(s.capacity() >= 100);
/// ```
#[inline]
pub fn capacity(&self) -> uint {
let &BitvSet(ref bitv) = self;
bitv.capacity()
}
/// Grows the underlying vector to be able to store `size` bits.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
///
/// let mut s = BitvSet::new();
/// s.reserve(10);
/// assert!(s.capacity() >= 10);
/// ```
pub fn reserve(&mut self, size: uint) {
let &BitvSet(ref mut bitv) = self;
bitv.reserve(size)
}
/// Consume this set to return the underlying bit vector.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
///
/// let mut s = BitvSet::new();
/// s.insert(0);
/// s.insert(3);
///
/// let bv = s.unwrap();
/// assert!(bv.eq_vec([true, false, false, true]));
/// ```
#[inline]
pub fn unwrap(self) -> Bitv {
let BitvSet(bitv) = self;
bitv
}
/// Return a reference to the underlying bit vector.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
///
/// let mut s = BitvSet::new();
/// s.insert(0);
///
/// let bv = s.get_ref();
/// assert_eq!(bv[0], true);
/// ```
#[inline]
pub fn get_ref<'a>(&'a self) -> &'a Bitv {
let &BitvSet(ref bitv) = self;
bitv
}
/// Return a mutable reference to the underlying bit vector.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
///
/// let mut s = BitvSet::new();
/// s.insert(0);
/// assert_eq!(s.contains(&0), true);
/// {
/// // Will free the set during bv's lifetime
/// let bv = s.get_mut_ref();
/// bv.set(0, false);
/// }
/// assert_eq!(s.contains(&0), false);
/// ```
#[inline]
pub fn get_mut_ref<'a>(&'a mut self) -> &'a mut Bitv {
let &BitvSet(ref mut bitv) = self;
bitv
}
#[inline]
fn other_op(&mut self, other: &BitvSet, f: |uint, uint| -> uint) {
// Unwrap Bitvs
let &BitvSet(ref mut self_bitv) = self;
let &BitvSet(ref other_bitv) = other;
// Expand the vector if necessary
self_bitv.reserve(other_bitv.capacity());
// Apply values
for (i, w) in other_bitv.mask_words(0) {
let old = *self_bitv.storage.get(i);
let new = f(old, w);
*self_bitv.storage.get_mut(i) = new;
}
}
/// Truncate the underlying vector to the least length required.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
///
/// let mut s = BitvSet::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]
pub fn shrink_to_fit(&mut self) {
let &BitvSet(ref mut bitv) = self;
// Obtain original length
let old_len = bitv.storage.len();
// Obtain coarse trailing zero length
let n = bitv.storage.iter().rev().take_while(|&&n| n == 0).count();
// Truncate
let trunc_len = cmp::max(old_len - n, 1);
bitv.storage.truncate(trunc_len);
bitv.nbits = trunc_len * uint::BITS;
}
/// Iterator over each uint stored in the BitvSet.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
/// use std::collections::bitv;
///
/// let s = BitvSet::from_bitv(bitv::from_bytes([0b01001010]));
///
/// // Print 1, 4, 6 in arbitrary order
/// for x in s.iter() {
/// println!("{}", x);
/// }
/// ```
#[inline]
pub fn iter<'a>(&'a self) -> BitPositions<'a> {
BitPositions {set: self, next_idx: 0}
}
/// Iterator over each uint stored in `self` union `other`.
/// See [union_with](#method.union_with) for an efficient in-place version.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
/// use std::collections::bitv;
///
/// let a = BitvSet::from_bitv(bitv::from_bytes([0b01101000]));
/// let b = BitvSet::from_bitv(bitv::from_bytes([0b10100000]));
///
/// // Print 0, 1, 2, 4 in arbitrary order
/// for x in a.union(&b) {
/// println!("{}", x);
/// }
/// ```
#[inline]
pub fn union<'a>(&'a self, other: &'a BitvSet) -> TwoBitPositions<'a> {
TwoBitPositions {
set: self,
other: other,
merge: |w1, w2| w1 | w2,
current_word: 0,
next_idx: 0
}
}
/// Iterator over each uint stored in `self` intersect `other`.
/// See [intersect_with](#method.intersect_with) for an efficient in-place version.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
/// use std::collections::bitv;
///
/// let a = BitvSet::from_bitv(bitv::from_bytes([0b01101000]));
/// let b = BitvSet::from_bitv(bitv::from_bytes([0b10100000]));
///
/// // Print 2
/// for x in a.intersection(&b) {
/// println!("{}", x);
/// }
/// ```
#[inline]
pub fn intersection<'a>(&'a self, other: &'a BitvSet) -> Take<TwoBitPositions<'a>> {
let min = cmp::min(self.capacity(), other.capacity());
TwoBitPositions {
set: self,
other: other,
merge: |w1, w2| w1 & w2,
current_word: 0,
next_idx: 0
}.take(min)
}
/// Iterator over each uint stored in the `self` setminus `other`.
/// See [difference_with](#method.difference_with) for an efficient in-place version.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
/// use std::collections::bitv;
///
/// let a = BitvSet::from_bitv(bitv::from_bytes([0b01101000]));
/// let b = BitvSet::from_bitv(bitv::from_bytes([0b10100000]));
///
/// // Print 2, 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]
pub fn difference<'a>(&'a self, other: &'a BitvSet) -> TwoBitPositions<'a> {
TwoBitPositions {
set: self,
other: other,
merge: |w1, w2| w1 & !w2,
current_word: 0,
next_idx: 0
}
}
/// Iterator over each uint stored in the symmetric difference of `self` and `other`.
/// See [symmetric_difference_with](#method.symmetric_difference_with) for
/// an efficient in-place version.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
/// use std::collections::bitv;
///
/// let a = BitvSet::from_bitv(bitv::from_bytes([0b01101000]));
/// let b = BitvSet::from_bitv(bitv::from_bytes([0b10100000]));
///
/// // Print 0, 1, 4 in arbitrary order
/// for x in a.symmetric_difference(&b) {
/// println!("{}", x);
/// }
/// ```
#[inline]
pub fn symmetric_difference<'a>(&'a self, other: &'a BitvSet) -> TwoBitPositions<'a> {
TwoBitPositions {
set: self,
other: other,
merge: |w1, w2| w1 ^ w2,
current_word: 0,
next_idx: 0
}
}
/// Union in-place with the specified other bit vector.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
/// use std::collections::bitv;
///
/// let a = 0b01101000;
/// let b = 0b10100000;
/// let res = 0b11101000;
///
/// let mut a = BitvSet::from_bitv(bitv::from_bytes([a]));
/// let b = BitvSet::from_bitv(bitv::from_bytes([b]));
///
/// a.union_with(&b);
/// assert_eq!(a.unwrap(), bitv::from_bytes([res]));
/// ```
#[inline]
pub fn union_with(&mut self, other: &BitvSet) {
self.other_op(other, |w1, w2| w1 | w2);
}
/// Intersect in-place with the specified other bit vector.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
/// use std::collections::bitv;
///
/// let a = 0b01101000;
/// let b = 0b10100000;
/// let res = 0b00100000;
///
/// let mut a = BitvSet::from_bitv(bitv::from_bytes([a]));
/// let b = BitvSet::from_bitv(bitv::from_bytes([b]));
///
/// a.intersect_with(&b);
/// assert_eq!(a.unwrap(), bitv::from_bytes([res]));
/// ```
#[inline]
pub fn intersect_with(&mut self, other: &BitvSet) {
self.other_op(other, |w1, w2| w1 & w2);
}
/// Difference in-place with the specified other bit vector.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
/// use std::collections::bitv;
///
/// let a = 0b01101000;
/// let b = 0b10100000;
/// let a_b = 0b01001000; // a - b
/// let b_a = 0b10000000; // b - a
///
/// let mut bva = BitvSet::from_bitv(bitv::from_bytes([a]));
/// let bvb = BitvSet::from_bitv(bitv::from_bytes([b]));
///
/// bva.difference_with(&bvb);
/// assert_eq!(bva.unwrap(), bitv::from_bytes([a_b]));
///
/// let bva = BitvSet::from_bitv(bitv::from_bytes([a]));
/// let mut bvb = BitvSet::from_bitv(bitv::from_bytes([b]));
///
/// bvb.difference_with(&bva);
/// assert_eq!(bvb.unwrap(), bitv::from_bytes([b_a]));
/// ```
#[inline]
pub fn difference_with(&mut self, other: &BitvSet) {
self.other_op(other, |w1, w2| w1 & !w2);
}
/// Symmetric difference in-place with the specified other bit vector.
///
/// # Example
///
/// ```
/// use std::collections::BitvSet;
/// use std::collections::bitv;
///
/// let a = 0b01101000;
/// let b = 0b10100000;
/// let res = 0b11001000;
///
/// let mut a = BitvSet::from_bitv(bitv::from_bytes([a]));
/// let b = BitvSet::from_bitv(bitv::from_bytes([b]));
///
/// a.symmetric_difference_with(&b);
/// assert_eq!(a.unwrap(), bitv::from_bytes([res]));
/// ```
#[inline]
pub fn symmetric_difference_with(&mut self, other: &BitvSet) {
self.other_op(other, |w1, w2| w1 ^ w2);
}
}
impl fmt::Show for BitvSet {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
try!(write!(fmt, "{{"));
let mut first = true;
for n in self.iter() {
if !first {
try!(write!(fmt, ", "));
}
try!(write!(fmt, "{}", n));
first = false;
}
write!(fmt, "}}")
}
}
impl<S: hash::Writer> hash::Hash<S> for BitvSet {
fn hash(&self, state: &mut S) {
for pos in self.iter() {
pos.hash(state);
}
}
}
impl Collection for BitvSet {
#[inline]
fn len(&self) -> uint {
let &BitvSet(ref bitv) = self;
bitv.storage.iter().fold(0, |acc, &n| acc + n.count_ones())
}
}
impl Mutable for BitvSet {
#[inline]
fn clear(&mut self) {
let &BitvSet(ref mut bitv) = self;
bitv.clear();
}
}
impl Set<uint> for BitvSet {
#[inline]
fn contains(&self, value: &uint) -> bool {
let &BitvSet(ref bitv) = self;
*value < bitv.nbits && bitv.get(*value)
}
#[inline]
fn is_disjoint(&self, other: &BitvSet) -> bool {
self.intersection(other).count() > 0
}
#[inline]
fn is_subset(&self, other: &BitvSet) -> bool {
let &BitvSet(ref self_bitv) = self;
let &BitvSet(ref other_bitv) = other;
// Check that `self` intersect `other` is self
self_bitv.mask_words(0).zip(other_bitv.mask_words(0))
.all(|((_, w1), (_, w2))| w1 & w2 == w1) &&
// Check that `self` setminus `other` is empty
self_bitv.mask_words(other_bitv.storage.len()).all(|(_, w)| w == 0)
}
#[inline]
fn is_superset(&self, other: &BitvSet) -> bool {
other.is_subset(self)
}
}
impl MutableSet<uint> for BitvSet {
fn insert(&mut self, value: uint) -> bool {
if self.contains(&value) {
return false;
}
if value >= self.capacity() {
let new_cap = cmp::max(value + 1, self.capacity() * 2);
self.reserve(new_cap);
}
let &BitvSet(ref mut bitv) = self;
if value >= bitv.nbits {
// If we are increasing nbits, make sure we mask out any previously-unconsidered bits
let old_rem = bitv.nbits % uint::BITS;
if old_rem != 0 {
let old_last_word = (bitv.nbits + uint::BITS - 1) / uint::BITS - 1;
*bitv.storage.get_mut(old_last_word) &= (1 << old_rem) - 1;
}
bitv.nbits = value + 1;
}
bitv.set(value, true);
return true;
}
fn remove(&mut self, value: &uint) -> bool {
if !self.contains(value) {
return false;
}
let &BitvSet(ref mut bitv) = self;
bitv.set(*value, false);
return true;
}
}
/// An iterator for `BitvSet`.
pub struct BitPositions<'a> {
set: &'a BitvSet,
next_idx: uint
}
/// An iterator combining wo `BitvSet` iterators.
pub struct TwoBitPositions<'a> {
set: &'a BitvSet,
other: &'a BitvSet,
merge: |uint, uint|: 'a -> uint,
current_word: uint,
next_idx: uint
}
impl<'a> Iterator<uint> for BitPositions<'a> {
fn next(&mut self) -> Option<uint> {
while self.next_idx < self.set.capacity() {
let idx = self.next_idx;
self.next_idx += 1;
if self.set.contains(&idx) {
return Some(idx);
}
}
return None;
}
#[inline]
fn size_hint(&self) -> (uint, Option<uint>) {
(0, Some(self.set.capacity() - self.next_idx))
}
}
impl<'a> Iterator<uint> for TwoBitPositions<'a> {
fn next(&mut self) -> Option<uint> {
while self.next_idx < self.set.capacity() ||
self.next_idx < self.other.capacity() {
let bit_idx = self.next_idx % uint::BITS;
if bit_idx == 0 {
let &BitvSet(ref s_bitv) = self.set;
let &BitvSet(ref o_bitv) = self.other;
// Merging the two words is a bit of an awkward dance since
// one Bitv might be longer than the other
let word_idx = self.next_idx / uint::BITS;
let w1 = if word_idx < s_bitv.storage.len() {
*s_bitv.storage.get(word_idx)
} else { 0 };
let w2 = if word_idx < o_bitv.storage.len() {
*o_bitv.storage.get(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) -> (uint, Option<uint>) {
let cap = cmp::max(self.set.capacity(), self.other.capacity());
(0, Some(cap - self.next_idx))
}
}
#[cfg(test)]
mod tests {
use std::prelude::*;
use std::uint;
use std::rand;
use std::rand::Rng;
use test::Bencher;
use {Set, Mutable, MutableSet, MutableSeq};
use bitv::{Bitv, BitvSet, from_fn, from_bytes};
use bitv;
use vec::Vec;
static BENCH_BITS : uint = 1 << 14;
#[test]
fn test_to_str() {
let zerolen = Bitv::new();
assert_eq!(zerolen.to_string().as_slice(), "");
let eightbits = Bitv::with_capacity(8u, false);
assert_eq!(eightbits.to_string().as_slice(), "00000000")
}
#[test]
fn test_0_elements() {
let act = Bitv::new();
let exp = Vec::from_elem(0u, false);
assert!(act.eq_vec(exp.as_slice()));
}
#[test]
fn test_1_element() {
let mut act = Bitv::with_capacity(1u, false);
assert!(act.eq_vec([false]));
act = Bitv::with_capacity(1u, true);
assert!(act.eq_vec([true]));
}
#[test]
fn test_2_elements() {
let mut b = bitv::Bitv::with_capacity(2, false);
b.set(0, true);
b.set(1, false);
assert_eq!(b.to_string().as_slice(), "10");
}
#[test]
fn test_10_elements() {
let mut act;
// all 0
act = Bitv::with_capacity(10u, false);
assert!((act.eq_vec(
[false, false, false, false, false, false, false, false, false, false])));
// all 1
act = Bitv::with_capacity(10u, true);
assert!((act.eq_vec([true, true, true, true, true, true, true, true, true, true])));
// mixed
act = Bitv::with_capacity(10u, false);
act.set(0u, true);
act.set(1u, true);
act.set(2u, true);
act.set(3u, true);
act.set(4u, true);
assert!((act.eq_vec([true, true, true, true, true, false, false, false, false, false])));
// mixed
act = Bitv::with_capacity(10u, false);
act.set(5u, true);
act.set(6u, true);
act.set(7u, true);
act.set(8u, true);
act.set(9u, true);
assert!((act.eq_vec([false, false, false, false, false, true, true, true, true, true])));
// mixed
act = Bitv::with_capacity(10u, false);
act.set(0u, true);
act.set(3u, true);
act.set(6u, true);
act.set(9u, true);
assert!((act.eq_vec([true, false, false, true, false, false, true, false, false, true])));
}
#[test]
fn test_31_elements() {
let mut act;
// all 0
act = Bitv::with_capacity(31u, 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]));
// all 1
act = Bitv::with_capacity(31u, 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]));
// mixed
act = Bitv::with_capacity(31u, false);
act.set(0u, true);
act.set(1u, true);
act.set(2u, true);
act.set(3u, true);
act.set(4u, true);
act.set(5u, true);
act.set(6u, true);
act.set(7u, 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]));
// mixed
act = Bitv::with_capacity(31u, false);
act.set(16u, true);
act.set(17u, true);
act.set(18u, true);
act.set(19u, true);
act.set(20u, true);
act.set(21u, true);
act.set(22u, true);
act.set(23u, 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]));
// mixed
act = Bitv::with_capacity(31u, false);
act.set(24u, true);
act.set(25u, true);
act.set(26u, true);
act.set(27u, true);
act.set(28u, true);
act.set(29u, true);
act.set(30u, 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]));
// mixed
act = Bitv::with_capacity(31u, false);
act.set(3u, true);
act.set(17u, true);
act.set(30u, 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]));
}
#[test]
fn test_32_elements() {
let mut act;
// all 0
act = Bitv::with_capacity(32u, 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]));
// all 1
act = Bitv::with_capacity(32u, 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]));
// mixed
act = Bitv::with_capacity(32u, false);
act.set(0u, true);
act.set(1u, true);
act.set(2u, true);
act.set(3u, true);
act.set(4u, true);
act.set(5u, true);
act.set(6u, true);
act.set(7u, 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]));
// mixed
act = Bitv::with_capacity(32u, false);
act.set(16u, true);
act.set(17u, true);
act.set(18u, true);
act.set(19u, true);
act.set(20u, true);
act.set(21u, true);
act.set(22u, true);
act.set(23u, 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]));
// mixed
act = Bitv::with_capacity(32u, false);
act.set(24u, true);
act.set(25u, true);
act.set(26u, true);
act.set(27u, true);
act.set(28u, true);
act.set(29u, true);
act.set(30u, true);
act.set(31u, 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]));
// mixed
act = Bitv::with_capacity(32u, false);
act.set(3u, true);
act.set(17u, true);
act.set(30u, true);
act.set(31u, 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]));
}
#[test]
fn test_33_elements() {
let mut act;
// all 0
act = Bitv::with_capacity(33u, 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]));
// all 1
act = Bitv::with_capacity(33u, 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]));
// mixed
act = Bitv::with_capacity(33u, false);
act.set(0u, true);
act.set(1u, true);
act.set(2u, true);
act.set(3u, true);
act.set(4u, true);
act.set(5u, true);
act.set(6u, true);
act.set(7u, 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]));
// mixed
act = Bitv::with_capacity(33u, false);
act.set(16u, true);
act.set(17u, true);
act.set(18u, true);
act.set(19u, true);
act.set(20u, true);
act.set(21u, true);
act.set(22u, true);
act.set(23u, 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]));
// mixed
act = Bitv::with_capacity(33u, false);
act.set(24u, true);
act.set(25u, true);
act.set(26u, true);
act.set(27u, true);
act.set(28u, true);
act.set(29u, true);
act.set(30u, true);
act.set(31u, 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]));
// mixed
act = Bitv::with_capacity(33u, false);
act.set(3u, true);
act.set(17u, true);
act.set(30u, true);
act.set(31u, true);
act.set(32u, 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]));
}
#[test]
fn test_equal_differing_sizes() {
let v0 = Bitv::with_capacity(10u, false);
let v1 = Bitv::with_capacity(11u, false);
assert!(v0 != v1);
}
#[test]
fn test_equal_greatly_differing_sizes() {
let v0 = Bitv::with_capacity(10u, false);
let v1 = Bitv::with_capacity(110u, false);
assert!(v0 != v1);
}
#[test]
fn test_equal_sneaky_small() {
let mut a = bitv::Bitv::with_capacity(1, false);
a.set(0, true);
let mut b = bitv::Bitv::with_capacity(1, true);
b.set(0, true);
assert_eq!(a, b);
}
#[test]
fn test_equal_sneaky_big() {
let mut a = bitv::Bitv::with_capacity(100, false);
for i in range(0u, 100) {
a.set(i, true);
}
let mut b = bitv::Bitv::with_capacity(100, true);
for i in range(0u, 100) {
b.set(i, true);
}
assert_eq!(a, b);
}
#[test]
fn test_from_bytes() {
let bitv = from_bytes([0b10110110, 0b00000000, 0b11111111]);
let str = format!("{}{}{}", "10110110", "00000000", "11111111");
assert_eq!(bitv.to_string().as_slice(), str.as_slice());
}
#[test]
fn test_to_bytes() {
let mut bv = Bitv::with_capacity(3, true);
bv.set(1, false);
assert_eq!(bv.to_bytes(), vec!(0b10100000));
let mut bv = Bitv::with_capacity(9, false);
bv.set(2, true);
bv.set(8, true);
assert_eq!(bv.to_bytes(), vec!(0b00100000, 0b10000000));
}
#[test]
fn test_from_bools() {
let bools = vec![true, false, true, true];
let bitv: Bitv = bools.iter().map(|n| *n).collect();
assert_eq!(bitv.to_string().as_slice(), "1011");
}
#[test]
fn test_to_bools() {
let bools = vec!(false, false, true, false, false, true, true, false);
assert_eq!(from_bytes([0b00100110]).iter().collect::<Vec<bool>>(), bools);
}
#[test]
fn test_bitv_iterator() {
let bools = [true, false, true, true];
let bitv: Bitv = bools.iter().map(|n| *n).collect();
for (act, &ex) in bitv.iter().zip(bools.iter()) {
assert_eq!(ex, act);
}
}
#[test]
fn test_bitv_set_iterator() {
let bools = [true, false, true, true];
let bitv = BitvSet::from_bitv(bools.iter().map(|n| *n).collect());
let idxs: Vec<uint> = bitv.iter().collect();
assert_eq!(idxs, vec!(0, 2, 3));
}
#[test]
fn test_bitv_set_frombitv_init() {
let bools = [true, false];
let lengths = [10, 64, 100];
for &b in bools.iter() {
for &l in lengths.iter() {
let bitset = BitvSet::from_bitv(Bitv::with_capacity(l, b));
assert_eq!(bitset.contains(&1u), b)
assert_eq!(bitset.contains(&(l-1u)), b)
assert!(!bitset.contains(&l))
}
}
}
#[test]
fn test_small_difference() {
let mut b1 = Bitv::with_capacity(3, false);
let mut b2 = Bitv::with_capacity(3, false);
b1.set(0, true);
b1.set(1, true);
b2.set(1, true);
b2.set(2, true);
assert!(b1.difference(&b2));
assert!(b1.get(0));
assert!(!b1.get(1));
assert!(!b1.get(2));
}
#[test]
fn test_big_difference() {
let mut b1 = Bitv::with_capacity(100, false);
let mut b2 = Bitv::with_capacity(100, false);
b1.set(0, true);
b1.set(40, true);
b2.set(40, true);
b2.set(80, true);
assert!(b1.difference(&b2));
assert!(b1.get(0));
assert!(!b1.get(40));
assert!(!b1.get(80));
}
#[test]
fn test_small_clear() {
let mut b = Bitv::with_capacity(14, true);
b.clear();
assert!(b.none());
}
#[test]
fn test_big_clear() {
let mut b = Bitv::with_capacity(140, true);
b.clear();
assert!(b.none());
}
#[test]
fn test_bitv_masking() {
let b = Bitv::with_capacity(140, true);
let mut bs = BitvSet::from_bitv(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_bitv_set_basic() {
// calculate nbits with uint::BITS granularity
fn calc_nbits(bits: uint) -> uint {
uint::BITS * ((bits + uint::BITS - 1) / uint::BITS)
}
let mut b = BitvSet::new();
assert_eq!(b.capacity(), calc_nbits(0));
assert!(b.insert(3));
assert_eq!(b.capacity(), calc_nbits(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_eq!(b.capacity(), calc_nbits(400));
assert!(!b.insert(400));
assert!(b.contains(&400));
assert_eq!(b.len(), 3);
}
#[test]
fn test_bitv_set_intersection() {
let mut a = BitvSet::new();
let mut b = BitvSet::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 = a.intersection(&b).collect::<Vec<uint>>();
assert_eq!(actual.as_slice(), expected.as_slice());
}
#[test]
fn test_bitv_set_difference() {
let mut a = BitvSet::new();
let mut b = BitvSet::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 = a.difference(&b).collect::<Vec<uint>>();
assert_eq!(actual.as_slice(), expected.as_slice());
}
#[test]
fn test_bitv_set_symmetric_difference() {
let mut a = BitvSet::new();
let mut b = BitvSet::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 = a.symmetric_difference(&b).collect::<Vec<uint>>();
assert_eq!(actual.as_slice(), expected.as_slice());
}
#[test]
fn test_bitv_set_union() {
let mut a = BitvSet::new();
let mut b = BitvSet::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!(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];
let actual = a.union(&b).collect::<Vec<uint>>();
assert_eq!(actual.as_slice(), expected.as_slice());
}
#[test]
fn test_bitv_set_subset() {
let mut set1 = BitvSet::new();
let mut set2 = BitvSet::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_bitv_remove() {
let mut a = BitvSet::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();
assert_eq!(a.capacity(), uint::BITS);
}
#[test]
fn test_bitv_lt() {
let mut a = Bitv::with_capacity(5u, false);
let mut b = Bitv::with_capacity(5u, 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 = Bitv::with_capacity(5u, false);
let mut b = Bitv::with_capacity(5u, 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_bitv_clone() {
let mut a = BitvSet::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));
}
#[test]
fn test_small_bitv_tests() {
let v = from_bytes([0]);
assert!(!v.all());
assert!(!v.any());
assert!(v.none());
let v = from_bytes([0b00010100]);
assert!(!v.all());
assert!(v.any());
assert!(!v.none());
let v = from_bytes([0xFF]);
assert!(v.all());
assert!(v.any());
assert!(!v.none());
}
#[test]
fn test_big_bitv_tests() {
let v = 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 = 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 = 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_bitv_push_pop() {
let mut s = Bitv::with_capacity(5 * uint::BITS - 2, false);
assert_eq!(s.len(), 5 * uint::BITS - 2);
assert_eq!(s.get(5 * uint::BITS - 3), false);
s.push(true);
s.push(true);
assert_eq!(s.get(5 * uint::BITS - 2), true);
assert_eq!(s.get(5 * uint::BITS - 1), true);
// Here the internal vector will need to be extended
s.push(false);
assert_eq!(s.get(5 * uint::BITS), false);
s.push(false);
assert_eq!(s.get(5 * uint::BITS + 1), false);
assert_eq!(s.len(), 5 * uint::BITS + 2);
// Pop it all off
assert_eq!(s.pop(), false);
assert_eq!(s.pop(), false);
assert_eq!(s.pop(), true);
assert_eq!(s.pop(), true);
assert_eq!(s.len(), 5 * uint::BITS - 2);
}
#[test]
fn test_bitv_truncate() {
let mut s = Bitv::with_capacity(5 * uint::BITS, true);
assert_eq!(s, Bitv::with_capacity(5 * uint::BITS, true));
assert_eq!(s.len(), 5 * uint::BITS);
s.truncate(4 * uint::BITS);
assert_eq!(s, Bitv::with_capacity(4 * uint::BITS, true));
assert_eq!(s.len(), 4 * uint::BITS);
// Truncating to a size > s.len() should be a noop
s.truncate(5 * uint::BITS);
assert_eq!(s, Bitv::with_capacity(4 * uint::BITS, true));
assert_eq!(s.len(), 4 * uint::BITS);
s.truncate(3 * uint::BITS - 10);
assert_eq!(s, Bitv::with_capacity(3 * uint::BITS - 10, true));
assert_eq!(s.len(), 3 * uint::BITS - 10);
s.truncate(0);
assert_eq!(s, Bitv::with_capacity(0, true));
assert_eq!(s.len(), 0);
}
#[test]
fn test_bitv_reserve() {
let mut s = Bitv::with_capacity(5 * uint::BITS, true);
// Check capacity
assert_eq!(s.capacity(), 5 * uint::BITS);
s.reserve(2 * uint::BITS);
assert_eq!(s.capacity(), 5 * uint::BITS);
s.reserve(7 * uint::BITS);
assert_eq!(s.capacity(), 7 * uint::BITS);
s.reserve(7 * uint::BITS);
assert_eq!(s.capacity(), 7 * uint::BITS);
s.reserve(7 * uint::BITS + 1);
assert_eq!(s.capacity(), 8 * uint::BITS);
// Check that length hasn't changed
assert_eq!(s.len(), 5 * uint::BITS);
s.push(true);
s.push(false);
s.push(true);
assert_eq!(s.get(5 * uint::BITS - 1), true);
assert_eq!(s.get(5 * uint::BITS - 0), true);
assert_eq!(s.get(5 * uint::BITS + 1), false);
assert_eq!(s.get(5 * uint::BITS + 2), true);
}
#[test]
fn test_bitv_grow() {
let mut bitv = from_bytes([0b10110110, 0b00000000, 0b10101010]);
bitv.grow(32, true);
assert_eq!(bitv, from_bytes([0b10110110, 0b00000000, 0b10101010,
0xFF, 0xFF, 0xFF, 0xFF]));
bitv.grow(64, false);
assert_eq!(bitv, from_bytes([0b10110110, 0b00000000, 0b10101010,
0xFF, 0xFF, 0xFF, 0xFF, 0, 0, 0, 0, 0, 0, 0, 0]));
bitv.grow(16, true);
assert_eq!(bitv, from_bytes([0b10110110, 0b00000000, 0b10101010,
0xFF, 0xFF, 0xFF, 0xFF, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF]));
}
#[test]
fn test_bitv_extend() {
let mut bitv = from_bytes([0b10110110, 0b00000000, 0b11111111]);
let ext = from_bytes([0b01001001, 0b10010010, 0b10111101]);
bitv.extend(ext.iter());
assert_eq!(bitv, from_bytes([0b10110110, 0b00000000, 0b11111111,
0b01001001, 0b10010010, 0b10111101]));
}
#[test]
fn test_bitv_set_show() {
let mut s = BitvSet::new();
s.insert(1);
s.insert(10);
s.insert(50);
s.insert(2);
assert_eq!("{1, 2, 10, 50}".to_string(), s.to_string());
}
fn rng() -> rand::IsaacRng {
let seed = &[1, 2, 3, 4, 5, 6, 7, 8, 9, 0];
rand::SeedableRng::from_seed(seed)
}
#[bench]
fn bench_uint_small(b: &mut Bencher) {
let mut r = rng();
let mut bitv = 0 as uint;
b.iter(|| {
bitv |= 1 << ((r.next_u32() as uint) % uint::BITS);
&bitv
})
}
#[bench]
fn bench_bitv_big(b: &mut Bencher) {
let mut r = rng();
let mut bitv = Bitv::with_capacity(BENCH_BITS, false);
b.iter(|| {
bitv.set((r.next_u32() as uint) % BENCH_BITS, true);
&bitv
})
}
#[bench]
fn bench_bitv_small(b: &mut Bencher) {
let mut r = rng();
let mut bitv = Bitv::with_capacity(uint::BITS, false);
b.iter(|| {
bitv.set((r.next_u32() as uint) % uint::BITS, true);
&bitv
})
}
#[bench]
fn bench_bitv_set_small(b: &mut Bencher) {
let mut r = rng();
let mut bitv = BitvSet::new();
b.iter(|| {
bitv.insert((r.next_u32() as uint) % uint::BITS);
&bitv
})
}
#[bench]
fn bench_bitv_set_big(b: &mut Bencher) {
let mut r = rng();
let mut bitv = BitvSet::new();
b.iter(|| {
bitv.insert((r.next_u32() as uint) % BENCH_BITS);
&bitv
})
}
#[bench]
fn bench_bitv_big_union(b: &mut Bencher) {
let mut b1 = Bitv::with_capacity(BENCH_BITS, false);
let b2 = Bitv::with_capacity(BENCH_BITS, false);
b.iter(|| {
b1.union(&b2);
})
}
#[bench]
fn bench_btv_small_iter(b: &mut Bencher) {
let bitv = Bitv::with_capacity(uint::BITS, false);
b.iter(|| {
let mut _sum = 0;
for pres in bitv.iter() {
_sum += pres as uint;
}
})
}
#[bench]
fn bench_bitv_big_iter(b: &mut Bencher) {
let bitv = Bitv::with_capacity(BENCH_BITS, false);
b.iter(|| {
let mut _sum = 0;
for pres in bitv.iter() {
_sum += pres as uint;
}
})
}
#[bench]
fn bench_bitvset_iter(b: &mut Bencher) {
let bitv = BitvSet::from_bitv(from_fn(BENCH_BITS,
|idx| {idx % 3 == 0}));
b.iter(|| {
let mut _sum = 0;
for idx in bitv.iter() {
_sum += idx;
}
})
}
}