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// Copyright 2012-2018 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![deny(missing_docs)]
//! A simple map based on a vector for small integer keys. Space requirements
//! are O(highest integer key).
// optional serde support
#[cfg(feature = "serde")]
#[macro_use]
extern crate serde;
use self::Entry::*;
use std::cmp::{Ordering, max};
use std::fmt;
use std::hash::{Hash, Hasher};
use std::iter::{Enumerate, FilterMap, FromIterator};
use std::mem::{replace, swap};
use std::ops::{Index, IndexMut};
use std::slice;
use std::vec;
/// A map optimized for small integer keys.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut months = VecMap::new();
/// months.insert(1, "Jan");
/// months.insert(2, "Feb");
/// months.insert(3, "Mar");
///
/// if !months.contains_key(12) {
/// println!("The end is near!");
/// }
///
/// assert_eq!(months.get(1), Some(&"Jan"));
///
/// if let Some(value) = months.get_mut(3) {
/// *value = "Venus";
/// }
///
/// assert_eq!(months.get(3), Some(&"Venus"));
///
/// // Print out all months
/// for (key, value) in &months {
/// println!("month {} is {}", key, value);
/// }
///
/// months.clear();
/// assert!(months.is_empty());
/// ```
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
pub struct VecMap<V> {
n: usize,
v: Vec<Option<V>>,
}
/// A view into a single entry in a map, which may either be vacant or occupied.
pub enum Entry<'a, V: 'a> {
/// A vacant Entry
Vacant(VacantEntry<'a, V>),
/// An occupied Entry
Occupied(OccupiedEntry<'a, V>),
}
/// A vacant Entry.
pub struct VacantEntry<'a, V: 'a> {
map: &'a mut VecMap<V>,
index: usize,
}
/// An occupied Entry.
pub struct OccupiedEntry<'a, V: 'a> {
map: &'a mut VecMap<V>,
index: usize,
}
impl<V> Default for VecMap<V> {
#[inline]
fn default() -> Self { Self::new() }
}
impl<V: Hash> Hash for VecMap<V> {
fn hash<H: Hasher>(&self, state: &mut H) {
// In order to not traverse the `VecMap` twice, count the elements
// during iteration.
let mut count: usize = 0;
for elt in self {
elt.hash(state);
count += 1;
}
count.hash(state);
}
}
impl<V> VecMap<V> {
/// Creates an empty `VecMap`.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
/// let mut map: VecMap<&str> = VecMap::new();
/// ```
pub fn new() -> Self { VecMap { n: 0, v: vec![] } }
/// Creates an empty `VecMap` with space for at least `capacity`
/// elements before resizing.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
/// let mut map: VecMap<&str> = VecMap::with_capacity(10);
/// ```
pub fn with_capacity(capacity: usize) -> Self {
VecMap { n: 0, v: Vec::with_capacity(capacity) }
}
/// Returns the number of elements the `VecMap` can hold without
/// reallocating.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
/// let map: VecMap<String> = VecMap::with_capacity(10);
/// assert!(map.capacity() >= 10);
/// ```
#[inline]
pub fn capacity(&self) -> usize {
self.v.capacity()
}
/// Reserves capacity for the given `VecMap` to contain `len` distinct keys.
/// In the case of `VecMap` this means reallocations will not occur as long
/// as all inserted keys are less than `len`.
///
/// The collection may reserve more space to avoid frequent reallocations.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
/// let mut map: VecMap<&str> = VecMap::new();
/// map.reserve_len(10);
/// assert!(map.capacity() >= 10);
/// ```
pub fn reserve_len(&mut self, len: usize) {
let cur_len = self.v.len();
if len >= cur_len {
self.v.reserve(len - cur_len);
}
}
/// Reserves the minimum capacity for the given `VecMap` to contain `len` distinct keys.
/// In the case of `VecMap` this means reallocations will not occur as long as all inserted
/// keys are less than `len`.
///
/// Note that the allocator may give the collection more space than it requests.
/// Therefore capacity cannot be relied upon to be precisely minimal. Prefer
/// `reserve_len` if future insertions are expected.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
/// let mut map: VecMap<&str> = VecMap::new();
/// map.reserve_len_exact(10);
/// assert!(map.capacity() >= 10);
/// ```
pub fn reserve_len_exact(&mut self, len: usize) {
let cur_len = self.v.len();
if len >= cur_len {
self.v.reserve_exact(len - cur_len);
}
}
/// Trims the `VecMap` of any excess capacity.
///
/// The collection may reserve more space to avoid frequent reallocations.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
/// let mut map: VecMap<&str> = VecMap::with_capacity(10);
/// map.shrink_to_fit();
/// assert_eq!(map.capacity(), 0);
/// ```
pub fn shrink_to_fit(&mut self) {
// strip off trailing `None`s
if let Some(idx) = self.v.iter().rposition(Option::is_some) {
self.v.truncate(idx + 1);
} else {
self.v.clear();
}
self.v.shrink_to_fit()
}
/// Returns an iterator visiting all keys in ascending order of the keys.
/// The iterator's element type is `usize`.
pub fn keys(&self) -> Keys<V> {
Keys { iter: self.iter() }
}
/// Returns an iterator visiting all values in ascending order of the keys.
/// The iterator's element type is `&'r V`.
pub fn values(&self) -> Values<V> {
Values { iter: self.iter() }
}
/// Returns an iterator visiting all values in ascending order of the keys.
/// The iterator's element type is `&'r mut V`.
pub fn values_mut(&mut self) -> ValuesMut<V> {
ValuesMut { iter_mut: self.iter_mut() }
}
/// Returns an iterator visiting all key-value pairs in ascending order of the keys.
/// The iterator's element type is `(usize, &'r V)`.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut map = VecMap::new();
/// map.insert(1, "a");
/// map.insert(3, "c");
/// map.insert(2, "b");
///
/// // Print `1: a` then `2: b` then `3: c`
/// for (key, value) in map.iter() {
/// println!("{}: {}", key, value);
/// }
/// ```
pub fn iter(&self) -> Iter<V> {
Iter {
front: 0,
back: self.v.len(),
n: self.n,
yielded: 0,
iter: self.v.iter()
}
}
/// Returns an iterator visiting all key-value pairs in ascending order of the keys,
/// with mutable references to the values.
/// The iterator's element type is `(usize, &'r mut V)`.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut map = VecMap::new();
/// map.insert(1, "a");
/// map.insert(2, "b");
/// map.insert(3, "c");
///
/// for (key, value) in map.iter_mut() {
/// *value = "x";
/// }
///
/// for (key, value) in &map {
/// assert_eq!(value, &"x");
/// }
/// ```
pub fn iter_mut(&mut self) -> IterMut<V> {
IterMut {
front: 0,
back: self.v.len(),
n: self.n,
yielded: 0,
iter: self.v.iter_mut()
}
}
/// Moves all elements from `other` into the map while overwriting existing keys.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut a = VecMap::new();
/// a.insert(1, "a");
/// a.insert(2, "b");
///
/// let mut b = VecMap::new();
/// b.insert(3, "c");
/// b.insert(4, "d");
///
/// a.append(&mut b);
///
/// assert_eq!(a.len(), 4);
/// assert_eq!(b.len(), 0);
/// assert_eq!(a[1], "a");
/// assert_eq!(a[2], "b");
/// assert_eq!(a[3], "c");
/// assert_eq!(a[4], "d");
/// ```
pub fn append(&mut self, other: &mut Self) {
self.extend(other.drain());
}
/// Splits the collection into two at the given key.
///
/// Returns a newly allocated `Self`. `self` contains elements `[0, at)`,
/// and the returned `Self` contains elements `[at, max_key)`.
///
/// Note that the capacity of `self` does not change.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut a = VecMap::new();
/// a.insert(1, "a");
/// a.insert(2, "b");
/// a.insert(3, "c");
/// a.insert(4, "d");
///
/// let b = a.split_off(3);
///
/// assert_eq!(a[1], "a");
/// assert_eq!(a[2], "b");
///
/// assert_eq!(b[3], "c");
/// assert_eq!(b[4], "d");
/// ```
pub fn split_off(&mut self, at: usize) -> Self {
let mut other = VecMap::new();
if at == 0 {
// Move all elements to other
// The swap will also fix .n
swap(self, &mut other);
return other
} else if at >= self.v.len() {
// No elements to copy
return other;
}
// Look up the index of the first non-None item
let first_index = self.v.iter().position(|el| el.is_some());
let start_index = match first_index {
Some(index) => max(at, index),
None => {
// self has no elements
return other;
}
};
// Fill the new VecMap with `None`s until `start_index`
other.v.extend((0..start_index).map(|_| None));
// Move elements beginning with `start_index` from `self` into `other`
let mut taken = 0;
other.v.extend(self.v[start_index..].iter_mut().map(|el| {
let el = el.take();
if el.is_some() {
taken += 1;
}
el
}));
other.n = taken;
self.n -= taken;
other
}
/// Returns an iterator visiting all key-value pairs in ascending order of
/// the keys, emptying (but not consuming) the original `VecMap`.
/// The iterator's element type is `(usize, &'r V)`. Keeps the allocated memory for reuse.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut map = VecMap::new();
/// map.insert(1, "a");
/// map.insert(3, "c");
/// map.insert(2, "b");
///
/// let vec: Vec<(usize, &str)> = map.drain().collect();
///
/// assert_eq!(vec, [(1, "a"), (2, "b"), (3, "c")]);
/// ```
pub fn drain(&mut self) -> Drain<V> {
fn filter<A>((i, v): (usize, Option<A>)) -> Option<(usize, A)> {
v.map(|v| (i, v))
}
let filter: fn((usize, Option<V>)) -> Option<(usize, V)> = filter; // coerce to fn ptr
self.n = 0;
Drain { iter: self.v.drain(..).enumerate().filter_map(filter) }
}
/// Returns the number of elements in the map.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut a = VecMap::new();
/// assert_eq!(a.len(), 0);
/// a.insert(1, "a");
/// assert_eq!(a.len(), 1);
/// ```
pub fn len(&self) -> usize {
self.n
}
/// Returns true if the map contains no elements.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut a = VecMap::new();
/// assert!(a.is_empty());
/// a.insert(1, "a");
/// assert!(!a.is_empty());
/// ```
pub fn is_empty(&self) -> bool {
self.n == 0
}
/// Clears the map, removing all key-value pairs.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut a = VecMap::new();
/// a.insert(1, "a");
/// a.clear();
/// assert!(a.is_empty());
/// ```
pub fn clear(&mut self) { self.n = 0; self.v.clear() }
/// Returns a reference to the value corresponding to the key.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut map = VecMap::new();
/// map.insert(1, "a");
/// assert_eq!(map.get(1), Some(&"a"));
/// assert_eq!(map.get(2), None);
/// ```
pub fn get(&self, key: usize) -> Option<&V> {
if key < self.v.len() {
self.v[key].as_ref()
} else {
None
}
}
/// Returns true if the map contains a value for the specified key.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut map = VecMap::new();
/// map.insert(1, "a");
/// assert_eq!(map.contains_key(1), true);
/// assert_eq!(map.contains_key(2), false);
/// ```
#[inline]
pub fn contains_key(&self, key: usize) -> bool {
self.get(key).is_some()
}
/// Returns a mutable reference to the value corresponding to the key.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut map = VecMap::new();
/// map.insert(1, "a");
/// if let Some(x) = map.get_mut(1) {
/// *x = "b";
/// }
/// assert_eq!(map[1], "b");
/// ```
pub fn get_mut(&mut self, key: usize) -> Option<&mut V> {
if key < self.v.len() {
self.v[key].as_mut()
} else {
None
}
}
/// Inserts a key-value pair into the map. If the key already had a value
/// present in the map, that value is returned. Otherwise, `None` is returned.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut map = VecMap::new();
/// assert_eq!(map.insert(37, "a"), None);
/// assert_eq!(map.is_empty(), false);
///
/// map.insert(37, "b");
/// assert_eq!(map.insert(37, "c"), Some("b"));
/// assert_eq!(map[37], "c");
/// ```
pub fn insert(&mut self, key: usize, value: V) -> Option<V> {
let len = self.v.len();
if len <= key {
self.v.extend((0..key - len + 1).map(|_| None));
}
let was = replace(&mut self.v[key], Some(value));
if was.is_none() {
self.n += 1;
}
was
}
/// Removes a key from the map, returning the value at the key if the key
/// was previously in the map.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut map = VecMap::new();
/// map.insert(1, "a");
/// assert_eq!(map.remove(1), Some("a"));
/// assert_eq!(map.remove(1), None);
/// ```
pub fn remove(&mut self, key: usize) -> Option<V> {
if key >= self.v.len() {
return None;
}
let result = &mut self.v[key];
let was = result.take();
if was.is_some() {
self.n -= 1;
}
was
}
/// Gets the given key's corresponding entry in the map for in-place manipulation.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut count: VecMap<u32> = VecMap::new();
///
/// // count the number of occurrences of numbers in the vec
/// for x in vec![1, 2, 1, 2, 3, 4, 1, 2, 4] {
/// *count.entry(x).or_insert(0) += 1;
/// }
///
/// assert_eq!(count[1], 3);
/// ```
pub fn entry(&mut self, key: usize) -> Entry<V> {
// FIXME(Gankro): this is basically the dumbest implementation of
// entry possible, because weird non-lexical borrows issues make it
// completely insane to do any other way. That said, Entry is a border-line
// useless construct on VecMap, so it's hardly a big loss.
if self.contains_key(key) {
Occupied(OccupiedEntry {
map: self,
index: key,
})
} else {
Vacant(VacantEntry {
map: self,
index: key,
})
}
}
/// Retains only the elements specified by the predicate.
///
/// In other words, remove all pairs `(k, v)` such that `f(&k, &mut v)` returns `false`.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut map: VecMap<usize> = (0..8).map(|x|(x, x*10)).collect();
/// map.retain(|k, _| k % 2 == 0);
/// assert_eq!(map.len(), 4);
/// ```
pub fn retain<F>(&mut self, mut f: F)
where F: FnMut(usize, &mut V) -> bool
{
for (i, e) in self.v.iter_mut().enumerate() {
let remove = match *e {
Some(ref mut value) => !f(i, value),
None => false,
};
if remove {
*e = None;
self.n -= 1;
}
}
}
}
impl<'a, V> Entry<'a, V> {
/// Ensures a value is in the entry by inserting the default if empty, and
/// returns a mutable reference to the value in the entry.
pub fn or_insert(self, default: V) -> &'a mut V {
match self {
Occupied(entry) => entry.into_mut(),
Vacant(entry) => entry.insert(default),
}
}
/// Ensures a value is in the entry by inserting the result of the default
/// function if empty, and returns a mutable reference to the value in the
/// entry.
pub fn or_insert_with<F: FnOnce() -> V>(self, default: F) -> &'a mut V {
match self {
Occupied(entry) => entry.into_mut(),
Vacant(entry) => entry.insert(default()),
}
}
}
impl<'a, V> VacantEntry<'a, V> {
/// Sets the value of the entry with the VacantEntry's key,
/// and returns a mutable reference to it.
pub fn insert(self, value: V) -> &'a mut V {
let index = self.index;
self.map.insert(index, value);
&mut self.map[index]
}
}
impl<'a, V> OccupiedEntry<'a, V> {
/// Gets a reference to the value in the entry.
pub fn get(&self) -> &V {
let index = self.index;
&self.map[index]
}
/// Gets a mutable reference to the value in the entry.
pub fn get_mut(&mut self) -> &mut V {
let index = self.index;
&mut self.map[index]
}
/// Converts the entry into a mutable reference to its value.
pub fn into_mut(self) -> &'a mut V {
let index = self.index;
&mut self.map[index]
}
/// Sets the value of the entry with the OccupiedEntry's key,
/// and returns the entry's old value.
pub fn insert(&mut self, value: V) -> V {
let index = self.index;
self.map.insert(index, value).unwrap()
}
/// Takes the value of the entry out of the map, and returns it.
pub fn remove(self) -> V {
let index = self.index;
self.map.remove(index).unwrap()
}
}
impl<V: Clone> Clone for VecMap<V> {
#[inline]
fn clone(&self) -> Self {
VecMap { n: self.n, v: self.v.clone() }
}
#[inline]
fn clone_from(&mut self, source: &Self) {
self.v.clone_from(&source.v);
self.n = source.n;
}
}
impl<V: PartialEq> PartialEq for VecMap<V> {
fn eq(&self, other: &Self) -> bool {
self.n == other.n && self.iter().eq(other.iter())
}
}
impl<V: Eq> Eq for VecMap<V> {}
impl<V: PartialOrd> PartialOrd for VecMap<V> {
#[inline]
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
self.iter().partial_cmp(other.iter())
}
}
impl<V: Ord> Ord for VecMap<V> {
#[inline]
fn cmp(&self, other: &Self) -> Ordering {
self.iter().cmp(other.iter())
}
}
impl<V: fmt::Debug> fmt::Debug for VecMap<V> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_map().entries(self).finish()
}
}
impl<V> FromIterator<(usize, V)> for VecMap<V> {
fn from_iter<I: IntoIterator<Item = (usize, V)>>(iter: I) -> Self {
let mut map = Self::new();
map.extend(iter);
map
}
}
impl<T> IntoIterator for VecMap<T> {
type Item = (usize, T);
type IntoIter = IntoIter<T>;
/// Returns an iterator visiting all key-value pairs in ascending order of
/// the keys, consuming the original `VecMap`.
/// The iterator's element type is `(usize, &'r V)`.
///
/// # Examples
///
/// ```
/// use vec_map::VecMap;
///
/// let mut map = VecMap::new();
/// map.insert(1, "a");
/// map.insert(3, "c");
/// map.insert(2, "b");
///
/// let vec: Vec<(usize, &str)> = map.into_iter().collect();
///
/// assert_eq!(vec, [(1, "a"), (2, "b"), (3, "c")]);
/// ```
fn into_iter(self) -> IntoIter<T> {
IntoIter {
n: self.n,
yielded: 0,
iter: self.v.into_iter().enumerate()
}
}
}
impl<'a, T> IntoIterator for &'a VecMap<T> {
type Item = (usize, &'a T);
type IntoIter = Iter<'a, T>;
fn into_iter(self) -> Iter<'a, T> {
self.iter()
}
}
impl<'a, T> IntoIterator for &'a mut VecMap<T> {
type Item = (usize, &'a mut T);
type IntoIter = IterMut<'a, T>;
fn into_iter(self) -> IterMut<'a, T> {
self.iter_mut()
}
}
impl<V> Extend<(usize, V)> for VecMap<V> {
fn extend<I: IntoIterator<Item = (usize, V)>>(&mut self, iter: I) {
for (k, v) in iter {
self.insert(k, v);
}
}
}
impl<'a, V: Copy> Extend<(usize, &'a V)> for VecMap<V> {
fn extend<I: IntoIterator<Item = (usize, &'a V)>>(&mut self, iter: I) {
self.extend(iter.into_iter().map(|(key, &value)| (key, value)));
}
}
impl<V> Index<usize> for VecMap<V> {
type Output = V;
#[inline]
fn index(&self, i: usize) -> &V {
self.get(i).expect("key not present")
}
}
impl<'a, V> Index<&'a usize> for VecMap<V> {
type Output = V;
#[inline]
fn index(&self, i: &usize) -> &V {
self.get(*i).expect("key not present")
}
}
impl<V> IndexMut<usize> for VecMap<V> {
#[inline]
fn index_mut(&mut self, i: usize) -> &mut V {
self.get_mut(i).expect("key not present")
}
}
impl<'a, V> IndexMut<&'a usize> for VecMap<V> {
#[inline]
fn index_mut(&mut self, i: &usize) -> &mut V {
self.get_mut(*i).expect("key not present")
}
}
macro_rules! iterator {
(impl $name:ident -> $elem:ty, $($getter:ident),+) => {
impl<'a, V> Iterator for $name<'a, V> {
type Item = $elem;
#[inline]
fn next(&mut self) -> Option<$elem> {
while self.front < self.back {
if let Some(elem) = self.iter.next() {
if let Some(x) = elem$(. $getter ())+ {
let index = self.front;
self.front += 1;
self.yielded += 1;
return Some((index, x));
}
}
self.front += 1;
}
None
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
(self.n - self.yielded, Some(self.n - self.yielded))
}
}
}
}
macro_rules! double_ended_iterator {
(impl $name:ident -> $elem:ty, $($getter:ident),+) => {
impl<'a, V> DoubleEndedIterator for $name<'a, V> {
#[inline]
fn next_back(&mut self) -> Option<$elem> {
while self.front < self.back {
if let Some(elem) = self.iter.next_back() {
if let Some(x) = elem$(. $getter ())+ {
self.back -= 1;
return Some((self.back, x));
}
}
self.back -= 1;
}
None
}
}
}
}
/// An iterator over the key-value pairs of a map.
pub struct Iter<'a, V: 'a> {
front: usize,
back: usize,
n: usize,
yielded: usize,
iter: slice::Iter<'a, Option<V>>
}
// FIXME(#19839) Remove in favor of `#[derive(Clone)]`
impl<'a, V> Clone for Iter<'a, V> {
fn clone(&self) -> Iter<'a, V> {
Iter {
front: self.front,
back: self.back,
n: self.n,
yielded: self.yielded,
iter: self.iter.clone()
}
}
}
iterator! { impl Iter -> (usize, &'a V), as_ref }
impl<'a, V> ExactSizeIterator for Iter<'a, V> {}
double_ended_iterator! { impl Iter -> (usize, &'a V), as_ref }
/// An iterator over the key-value pairs of a map, with the
/// values being mutable.
pub struct IterMut<'a, V: 'a> {
front: usize,
back: usize,
n: usize,
yielded: usize,
iter: slice::IterMut<'a, Option<V>>
}
iterator! { impl IterMut -> (usize, &'a mut V), as_mut }
impl<'a, V> ExactSizeIterator for IterMut<'a, V> {}
double_ended_iterator! { impl IterMut -> (usize, &'a mut V), as_mut }
/// An iterator over the keys of a map.
pub struct Keys<'a, V: 'a> {
iter: Iter<'a, V>,
}
// FIXME(#19839) Remove in favor of `#[derive(Clone)]`
impl<'a, V> Clone for Keys<'a, V> {
fn clone(&self) -> Keys<'a, V> {
Keys {
iter: self.iter.clone()
}
}
}
/// An iterator over the values of a map.
pub struct Values<'a, V: 'a> {
iter: Iter<'a, V>,
}
// FIXME(#19839) Remove in favor of `#[derive(Clone)]`
impl<'a, V> Clone for Values<'a, V> {
fn clone(&self) -> Values<'a, V> {
Values {
iter: self.iter.clone()
}
}
}
/// An iterator over the values of a map.
pub struct ValuesMut<'a, V: 'a> {
iter_mut: IterMut<'a, V>,
}
/// A consuming iterator over the key-value pairs of a map.
pub struct IntoIter<V> {
n: usize,
yielded: usize,
iter: Enumerate<vec::IntoIter<Option<V>>>,
}
/// A draining iterator over the key-value pairs of a map.
pub struct Drain<'a, V: 'a> {
iter: FilterMap<
Enumerate<vec::Drain<'a, Option<V>>>,
fn((usize, Option<V>)) -> Option<(usize, V)>>
}
impl<'a, V> Iterator for Drain<'a, V> {
type Item = (usize, V);
fn next(&mut self) -> Option<(usize, V)> { self.iter.next() }
fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
}
impl<'a, V> ExactSizeIterator for Drain<'a, V> {}
impl<'a, V> DoubleEndedIterator for Drain<'a, V> {
fn next_back(&mut self) -> Option<(usize, V)> { self.iter.next_back() }
}
impl<'a, V> Iterator for Keys<'a, V> {
type Item = usize;
fn next(&mut self) -> Option<usize> { self.iter.next().map(|e| e.0) }
fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
}
impl<'a, V> ExactSizeIterator for Keys<'a, V> {}
impl<'a, V> DoubleEndedIterator for Keys<'a, V> {
fn next_back(&mut self) -> Option<usize> { self.iter.next_back().map(|e| e.0) }
}
impl<'a, V> Iterator for Values<'a, V> {
type Item = &'a V;
fn next(&mut self) -> Option<(&'a V)> { self.iter.next().map(|e| e.1) }
fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
}
impl<'a, V> ExactSizeIterator for Values<'a, V> {}
impl<'a, V> DoubleEndedIterator for Values<'a, V> {
fn next_back(&mut self) -> Option<(&'a V)> { self.iter.next_back().map(|e| e.1) }
}
impl<'a, V> Iterator for ValuesMut<'a, V> {
type Item = &'a mut V;
fn next(&mut self) -> Option<(&'a mut V)> { self.iter_mut.next().map(|e| e.1) }
fn size_hint(&self) -> (usize, Option<usize>) { self.iter_mut.size_hint() }
}
impl<'a, V> ExactSizeIterator for ValuesMut<'a, V> {}
impl<'a, V> DoubleEndedIterator for ValuesMut<'a, V> {
fn next_back(&mut self) -> Option<&'a mut V> { self.iter_mut.next_back().map(|e| e.1) }
}
impl<V> Iterator for IntoIter<V> {
type Item = (usize, V);
fn next(&mut self) -> Option<(usize, V)> {
loop {
match self.iter.next() {
None => return None,
Some((i, Some(value))) => {
self.yielded += 1;
return Some((i, value))
},
_ => {}
}
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
(self.n - self.yielded, Some(self.n - self.yielded))
}
}
impl<V> ExactSizeIterator for IntoIter<V> {}
impl<V> DoubleEndedIterator for IntoIter<V> {
fn next_back(&mut self) -> Option<(usize, V)> {
loop {
match self.iter.next_back() {
None => return None,
Some((i, Some(value))) => return Some((i, value)),
_ => {}
}
}
}
}
#[allow(dead_code)]
fn assert_properties() {
fn vec_map_covariant<'a, T>(map: VecMap<&'static T>) -> VecMap<&'a T> { map }
fn into_iter_covariant<'a, T>(iter: IntoIter<&'static T>) -> IntoIter<&'a T> { iter }
fn iter_covariant<'i, 'a, T>(iter: Iter<'i, &'static T>) -> Iter<'i, &'a T> { iter }
fn keys_covariant<'i, 'a, T>(iter: Keys<'i, &'static T>) -> Keys<'i, &'a T> { iter }
fn values_covariant<'i, 'a, T>(iter: Values<'i, &'static T>) -> Values<'i, &'a T> { iter }
}
#[cfg(test)]
mod test {
use super::VecMap;
use super::Entry::{Occupied, Vacant};
use std::hash::{Hash, Hasher};
use std::collections::hash_map::DefaultHasher;
#[test]
fn test_get_mut() {
let mut m = VecMap::new();
assert!(m.insert(1, 12).is_none());
assert!(m.insert(2, 8).is_none());
assert!(m.insert(5, 14).is_none());
let new = 100;
match m.get_mut(5) {
None => panic!(), Some(x) => *x = new
}
assert_eq!(m.get(5), Some(&new));
}
#[test]
fn test_len() {
let mut map = VecMap::new();
assert_eq!(map.len(), 0);
assert!(map.is_empty());
assert!(map.insert(5, 20).is_none());
assert_eq!(map.len(), 1);
assert!(!map.is_empty());
assert!(map.insert(11, 12).is_none());
assert_eq!(map.len(), 2);
assert!(!map.is_empty());
assert!(map.insert(14, 22).is_none());
assert_eq!(map.len(), 3);
assert!(!map.is_empty());
}
#[test]
fn test_clear() {
let mut map = VecMap::new();
assert!(map.insert(5, 20).is_none());
assert!(map.insert(11, 12).is_none());
assert!(map.insert(14, 22).is_none());
map.clear();
assert!(map.is_empty());
assert!(map.get(5).is_none());
assert!(map.get(11).is_none());
assert!(map.get(14).is_none());
}
#[test]
fn test_insert() {
let mut m = VecMap::new();
assert_eq!(m.insert(1, 2), None);
assert_eq!(m.insert(1, 3), Some(2));
assert_eq!(m.insert(1, 4), Some(3));
}
#[test]
fn test_remove() {
let mut m = VecMap::new();
m.insert(1, 2);
assert_eq!(m.remove(1), Some(2));
assert_eq!(m.remove(1), None);
}
#[test]
fn test_keys() {
let mut map = VecMap::new();
map.insert(1, 'a');
map.insert(2, 'b');
map.insert(3, 'c');
let keys: Vec<_> = map.keys().collect();
assert_eq!(keys.len(), 3);
assert!(keys.contains(&1));
assert!(keys.contains(&2));
assert!(keys.contains(&3));
}
#[test]
fn test_values() {
let mut map = VecMap::new();
map.insert(1, 'a');
map.insert(2, 'b');
map.insert(3, 'c');
let values: Vec<_> = map.values().cloned().collect();
assert_eq!(values.len(), 3);
assert!(values.contains(&'a'));
assert!(values.contains(&'b'));
assert!(values.contains(&'c'));
}
#[test]
fn test_iterator() {
let mut m = VecMap::new();
assert!(m.insert(0, 1).is_none());
assert!(m.insert(1, 2).is_none());
assert!(m.insert(3, 5).is_none());
assert!(m.insert(6, 10).is_none());
assert!(m.insert(10, 11).is_none());
let mut it = m.iter();
assert_eq!(it.size_hint(), (5, Some(5)));
assert_eq!(it.next().unwrap(), (0, &1));
assert_eq!(it.size_hint(), (4, Some(4)));
assert_eq!(it.next().unwrap(), (1, &2));
assert_eq!(it.size_hint(), (3, Some(3)));
assert_eq!(it.next().unwrap(), (3, &5));
assert_eq!(it.size_hint(), (2, Some(2)));
assert_eq!(it.next().unwrap(), (6, &10));
assert_eq!(it.size_hint(), (1, Some(1)));
assert_eq!(it.next().unwrap(), (10, &11));
assert_eq!(it.size_hint(), (0, Some(0)));
assert!(it.next().is_none());
}
#[test]
fn test_iterator_size_hints() {
let mut m = VecMap::new();
assert!(m.insert(0, 1).is_none());
assert!(m.insert(1, 2).is_none());
assert!(m.insert(3, 5).is_none());
assert!(m.insert(6, 10).is_none());
assert!(m.insert(10, 11).is_none());
assert_eq!(m.iter().size_hint(), (5, Some(5)));
assert_eq!(m.iter().rev().size_hint(), (5, Some(5)));
assert_eq!(m.iter_mut().size_hint(), (5, Some(5)));
assert_eq!(m.iter_mut().rev().size_hint(), (5, Some(5)));
}
#[test]
fn test_mut_iterator() {
let mut m = VecMap::new();
assert!(m.insert(0, 1).is_none());
assert!(m.insert(1, 2).is_none());
assert!(m.insert(3, 5).is_none());
assert!(m.insert(6, 10).is_none());
assert!(m.insert(10, 11).is_none());
for (k, v) in &mut m {
*v += k as isize;
}
let mut it = m.iter();
assert_eq!(it.next().unwrap(), (0, &1));
assert_eq!(it.next().unwrap(), (1, &3));
assert_eq!(it.next().unwrap(), (3, &8));
assert_eq!(it.next().unwrap(), (6, &16));
assert_eq!(it.next().unwrap(), (10, &21));
assert!(it.next().is_none());
}
#[test]
fn test_rev_iterator() {
let mut m = VecMap::new();
assert!(m.insert(0, 1).is_none());
assert!(m.insert(1, 2).is_none());
assert!(m.insert(3, 5).is_none());
assert!(m.insert(6, 10).is_none());
assert!(m.insert(10, 11).is_none());
let mut it = m.iter().rev();
assert_eq!(it.next().unwrap(), (10, &11));
assert_eq!(it.next().unwrap(), (6, &10));
assert_eq!(it.next().unwrap(), (3, &5));
assert_eq!(it.next().unwrap(), (1, &2));
assert_eq!(it.next().unwrap(), (0, &1));
assert!(it.next().is_none());
}
#[test]
fn test_mut_rev_iterator() {
let mut m = VecMap::new();
assert!(m.insert(0, 1).is_none());
assert!(m.insert(1, 2).is_none());
assert!(m.insert(3, 5).is_none());
assert!(m.insert(6, 10).is_none());
assert!(m.insert(10, 11).is_none());
for (k, v) in m.iter_mut().rev() {
*v += k as isize;
}
let mut it = m.iter();
assert_eq!(it.next().unwrap(), (0, &1));
assert_eq!(it.next().unwrap(), (1, &3));
assert_eq!(it.next().unwrap(), (3, &8));
assert_eq!(it.next().unwrap(), (6, &16));
assert_eq!(it.next().unwrap(), (10, &21));
assert!(it.next().is_none());
}
#[test]
fn test_move_iter() {
let mut m: VecMap<Box<_>> = VecMap::new();
m.insert(1, Box::new(2));
let mut called = false;
for (k, v) in m {
assert!(!called);
called = true;
assert_eq!(k, 1);
assert_eq!(v, Box::new(2));
}
assert!(called);
}
#[test]
fn test_drain_iterator() {
let mut map = VecMap::new();
map.insert(1, "a");
map.insert(3, "c");
map.insert(2, "b");
let vec: Vec<_> = map.drain().collect();
assert_eq!(vec, [(1, "a"), (2, "b"), (3, "c")]);
assert_eq!(map.len(), 0);
}
#[test]
fn test_append() {
let mut a = VecMap::new();
a.insert(1, "a");
a.insert(2, "b");
a.insert(3, "c");
let mut b = VecMap::new();
b.insert(3, "d"); // Overwrite element from a
b.insert(4, "e");
b.insert(5, "f");
a.append(&mut b);
assert_eq!(a.len(), 5);
assert_eq!(b.len(), 0);
// Capacity shouldn't change for possible reuse
assert!(b.capacity() >= 4);
assert_eq!(a[1], "a");
assert_eq!(a[2], "b");
assert_eq!(a[3], "d");
assert_eq!(a[4], "e");
assert_eq!(a[5], "f");
}
#[test]
fn test_split_off() {
// Split within the key range
let mut a = VecMap::new();
a.insert(1, "a");
a.insert(2, "b");
a.insert(3, "c");
a.insert(4, "d");
let b = a.split_off(3);
assert_eq!(a.len(), 2);
assert_eq!(b.len(), 2);
assert_eq!(a[1], "a");
assert_eq!(a[2], "b");
assert_eq!(b[3], "c");
assert_eq!(b[4], "d");
// Split at 0
a.clear();
a.insert(1, "a");
a.insert(2, "b");
a.insert(3, "c");
a.insert(4, "d");
let b = a.split_off(0);
assert_eq!(a.len(), 0);
assert_eq!(b.len(), 4);
assert_eq!(b[1], "a");
assert_eq!(b[2], "b");
assert_eq!(b[3], "c");
assert_eq!(b[4], "d");
// Split behind max_key
a.clear();
a.insert(1, "a");
a.insert(2, "b");
a.insert(3, "c");
a.insert(4, "d");
let b = a.split_off(5);
assert_eq!(a.len(), 4);
assert_eq!(b.len(), 0);
assert_eq!(a[1], "a");
assert_eq!(a[2], "b");
assert_eq!(a[3], "c");
assert_eq!(a[4], "d");
}
#[test]
fn test_show() {
let mut map = VecMap::new();
let empty = VecMap::<i32>::new();
map.insert(1, 2);
map.insert(3, 4);
let map_str = format!("{:?}", map);
assert!(map_str == "{1: 2, 3: 4}" || map_str == "{3: 4, 1: 2}");
assert_eq!(format!("{:?}", empty), "{}");
}
#[test]
fn test_clone() {
let mut a = VecMap::new();
a.insert(1, 'x');
a.insert(4, 'y');
a.insert(6, 'z');
assert_eq!(a.clone().iter().collect::<Vec<_>>(), [(1, &'x'), (4, &'y'), (6, &'z')]);
}
#[test]
fn test_eq() {
let mut a = VecMap::new();
let mut b = VecMap::new();
assert!(a == b);
assert!(a.insert(0, 5).is_none());
assert!(a != b);
assert!(b.insert(0, 4).is_none());
assert!(a != b);
assert!(a.insert(5, 19).is_none());
assert!(a != b);
assert!(!b.insert(0, 5).is_none());
assert!(a != b);
assert!(b.insert(5, 19).is_none());
assert!(a == b);
a = VecMap::new();
b = VecMap::with_capacity(1);
assert!(a == b);
}
#[test]
fn test_lt() {
let mut a = VecMap::new();
let mut b = VecMap::new();
assert!(!(a < b) && !(b < a));
assert!(b.insert(2, 5).is_none());
assert!(a < b);
assert!(a.insert(2, 7).is_none());
assert!(!(a < b) && b < a);
assert!(b.insert(1, 0).is_none());
assert!(b < a);
assert!(a.insert(0, 6).is_none());
assert!(a < b);
assert!(a.insert(6, 2).is_none());
assert!(a < b && !(b < a));
}
#[test]
fn test_ord() {
let mut a = VecMap::new();
let mut b = VecMap::new();
assert!(a <= b && a >= b);
assert!(a.insert(1, 1).is_none());
assert!(a > b && a >= b);
assert!(b < a && b <= a);
assert!(b.insert(2, 2).is_none());
assert!(b > a && b >= a);
assert!(a < b && a <= b);
}
#[test]
fn test_hash() {
fn hash<T: Hash>(t: &T) -> u64 {
let mut s = DefaultHasher::new();
t.hash(&mut s);
s.finish()
}
let mut x = VecMap::new();
let mut y = VecMap::new();
assert!(hash(&x) == hash(&y));
x.insert(1, 'a');
x.insert(2, 'b');
x.insert(3, 'c');
y.insert(3, 'c');
y.insert(2, 'b');
y.insert(1, 'a');
assert!(hash(&x) == hash(&y));
x.insert(1000, 'd');
x.remove(1000);
assert!(hash(&x) == hash(&y));
}
#[test]
fn test_from_iter() {
let xs = [(1, 'a'), (2, 'b'), (3, 'c'), (4, 'd'), (5, 'e')];
let map: VecMap<_> = xs.iter().cloned().collect();
for &(k, v) in &xs {
assert_eq!(map.get(k), Some(&v));
}
}
#[test]
fn test_index() {
let mut map = VecMap::new();
map.insert(1, 2);
map.insert(2, 1);
map.insert(3, 4);
assert_eq!(map[3], 4);
}
#[test]
#[should_panic]
fn test_index_nonexistent() {
let mut map = VecMap::new();
map.insert(1, 2);
map.insert(2, 1);
map.insert(3, 4);
map[4];
}
#[test]
fn test_entry() {
let xs = [(1, 10), (2, 20), (3, 30), (4, 40), (5, 50), (6, 60)];
let mut map: VecMap<_> = xs.iter().cloned().collect();
// Existing key (insert)
match map.entry(1) {
Vacant(_) => unreachable!(),
Occupied(mut view) => {
assert_eq!(view.get(), &10);
assert_eq!(view.insert(100), 10);
}
}
assert_eq!(map.get(1).unwrap(), &100);
assert_eq!(map.len(), 6);
// Existing key (update)
match map.entry(2) {
Vacant(_) => unreachable!(),
Occupied(mut view) => {
let v = view.get_mut();
*v *= 10;
}
}
assert_eq!(map.get(2).unwrap(), &200);
assert_eq!(map.len(), 6);
// Existing key (take)
match map.entry(3) {
Vacant(_) => unreachable!(),
Occupied(view) => {
assert_eq!(view.remove(), 30);
}
}
assert_eq!(map.get(3), None);
assert_eq!(map.len(), 5);
// Inexistent key (insert)
match map.entry(10) {
Occupied(_) => unreachable!(),
Vacant(view) => {
assert_eq!(*view.insert(1000), 1000);
}
}
assert_eq!(map.get(10).unwrap(), &1000);
assert_eq!(map.len(), 6);
}
#[test]
fn test_extend_ref() {
let mut a = VecMap::new();
a.insert(1, "one");
let mut b = VecMap::new();
b.insert(2, "two");
b.insert(3, "three");
a.extend(&b);
assert_eq!(a.len(), 3);
assert_eq!(a[&1], "one");
assert_eq!(a[&2], "two");
assert_eq!(a[&3], "three");
}
#[test]
#[cfg(feature = "serde")]
fn test_serde() {
use serde::{Serialize, Deserialize};
fn impls_serde_traits<'de, S: Serialize + Deserialize<'de>>() {}
impls_serde_traits::<VecMap<u32>>();
}
#[test]
fn test_retain() {
let mut map = VecMap::new();
map.insert(1, "one");
map.insert(2, "two");
map.insert(3, "three");
map.retain(|k, v| match k {
1 => false,
2 => {
*v = "two changed";
true
},
3 => false,
_ => panic!(),
});
assert_eq!(map.len(), 1);
assert_eq!(map.get(1), None);
assert_eq!(map[2], "two changed");
assert_eq!(map.get(3), None);
}
}