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//! Type definitions for an ordered map.
use core::borrow::Borrow;
use core::hash::Hash;
use core::iter::FusedIterator;
use core::ops::Index;
mod detail;
#[cfg(test)]
mod tests;
/// A hash table where the iteration order of the key-value pairs is independent of the hash values of the keys.
///
/// Provides an API compatible with both [`IndexMap`] and a custom implementation based on [`BTreeMap`].
///
/// [`IndexMap`]: indexmap::IndexMap
/// [`BTreeMap`]: alloc::collections::BTreeMap
#[derive(Debug, Clone)]
pub struct IndexMap<K, V> {
inner: detail::IndexMapImpl<K, V>,
}
impl<K, V> Default for IndexMap<K, V> {
#[inline]
fn default() -> Self {
Self {
inner: detail::IndexMapImpl::default(),
}
}
}
impl<K, V> IndexMap<K, V> {
/// Clears the [`IndexMap`], removing all elements.
#[inline]
pub fn clear(&mut self) {
self.inner.clear()
}
/// Returns the number of elements in the [`IndexMap`].
#[inline]
pub fn len(&self) -> usize {
self.inner.len()
}
/// Returns `true` if the [`IndexMap`] contains no elements.
#[inline]
pub fn is_empty(&self) -> bool {
self.inner.is_empty()
}
/// Returns an iterator that yields the items in the [`IndexMap`].
#[inline]
pub fn iter(&self) -> Iter<'_, K, V> {
Iter {
inner: self.inner.iter(),
}
}
/// Returns an iterator that yields the mutable items in the [`IndexMap`].
#[inline]
pub fn iter_mut(&mut self) -> IterMut<'_, K, V> {
IterMut {
inner: self.inner.iter_mut(),
}
}
/// Returns an iterator that yields the keys in the [`IndexMap`].
#[inline]
pub fn keys(&self) -> Keys<'_, K, V> {
Keys {
inner: self.inner.keys(),
}
}
/// Returns an iterator that yields the values in the [`IndexMap`].
#[inline]
pub fn values(&self) -> Values<'_, K, V> {
Values {
inner: self.inner.values(),
}
}
/// Returns a mutable iterator that yields the values in the [`IndexMap`].
#[inline]
pub fn values_mut(&mut self) -> ValuesMut<'_, K, V> {
ValuesMut {
inner: self.inner.values_mut(),
}
}
/// Returns the key-value entry at the given `index` if any.
#[inline]
pub fn get_index(&self, index: usize) -> Option<(&K, &V)> {
self.inner.get_index(index)
}
/// Returns the mutable key-value entry at the given `index` if any.
#[inline]
pub fn get_index_mut(&mut self, index: usize) -> Option<(&K, &mut V)> {
self.inner.get_index_mut(index)
}
}
impl<K, V> IndexMap<K, V>
where
K: Hash + Eq + Ord + Clone,
{
/// Reserves capacity for at least `additional` more elements to be inserted in the [`IndexMap`].
#[inline]
pub fn reserve(&mut self, additional: usize) {
#[cfg(not(feature = "no-hash-maps"))]
self.inner.reserve(additional);
#[cfg(feature = "no-hash-maps")]
let _ = additional;
}
/// Returns true if `key` is contains in the [`IndexMap`].
#[inline]
pub fn contains_key<Q: ?Sized>(&self, key: &Q) -> bool
where
K: Borrow<Q>,
Q: Hash + Eq + Ord,
{
self.inner.contains_key(key)
}
/// Returns a reference to the value corresponding to the `key`.
#[inline]
pub fn get<Q: ?Sized>(&self, key: &Q) -> Option<&V>
where
K: Borrow<Q>,
Q: Hash + Eq + Ord,
{
self.inner.get(key)
}
/// Return references to the key-value pair stored for `key`,
/// if it is present, else `None`.
#[inline]
pub fn get_key_value<Q: ?Sized>(&self, key: &Q) -> Option<(&K, &V)>
where
K: Borrow<Q>,
Q: Hash + Eq + Ord,
{
self.inner.get_key_value(key)
}
/// Returns the key-value pair corresponding to the supplied key
/// as well as the unique index of the returned key-value pair.
///
/// The supplied key may be any borrowed form of the map's key type,
/// but the ordering on the borrowed form *must* match the ordering
/// on the key type.
#[inline]
pub fn get_full<Q: ?Sized>(&self, key: &Q) -> Option<(usize, &K, &V)>
where
K: Borrow<Q> + Ord,
Q: Hash + Eq + Ord,
{
self.inner.get_full(key)
}
/// Returns a mutable reference to the value corresponding to the key.
#[inline]
pub fn get_mut<Q: ?Sized>(&mut self, key: &Q) -> Option<&mut V>
where
K: Borrow<Q>,
Q: Hash + Eq + Ord,
{
self.inner.get_mut(key)
}
/// Inserts a key-value pair into the [`IndexMap`].
///
/// If the map did not have this key present, `None` is returned.
///
/// If the map did have this key present, the value is updated, and the old
/// value is returned. The key is not updated, though; this matters for
/// types that can be `==` without being identical.
#[inline]
pub fn insert(&mut self, key: K, value: V) -> Option<V> {
self.inner.insert(key, value)
}
/// Remove the key-value pair equivalent to `key` and return its value.
///
/// Like [`Vec::swap_remove`], the pair is removed by swapping it with the
/// last element of the map and popping it off. **This perturbs
/// the position of what used to be the last element!**
///
/// Return `None` if `key` is not in map.
///
/// [`Vec::swap_remove`]: alloc::vec::Vec::swap_remove
#[inline]
pub fn swap_remove<Q>(&mut self, key: &Q) -> Option<V>
where
K: Borrow<Q>,
Q: ?Sized + Hash + Eq + Ord,
{
self.inner.swap_remove(key)
}
/// Remove and return the key-value pair equivalent to `key`.
///
/// Like [`Vec::swap_remove`], the pair is removed by swapping it with the
/// last element of the map and popping it off. **This perturbs
/// the position of what used to be the last element!**
///
/// Return `None` if `key` is not in map.
///
/// [`Vec::swap_remove`]: alloc::vec::Vec::swap_remove
#[inline]
pub fn swap_remove_entry<Q>(&mut self, key: &Q) -> Option<(K, V)>
where
K: Borrow<Q>,
Q: ?Sized + Hash + Eq + Ord,
{
self.inner.swap_remove_entry(key)
}
/// Gets the given key's corresponding entry in the [`IndexMap`] for in-place manipulation.
#[inline]
pub fn entry(&mut self, key: K) -> Entry<'_, K, V> {
match self.inner.entry(key) {
detail::EntryImpl::Occupied(entry) => Entry::Occupied(OccupiedEntry { inner: entry }),
detail::EntryImpl::Vacant(entry) => Entry::Vacant(VacantEntry { inner: entry }),
}
}
}
impl<K, Q, V> Index<&Q> for IndexMap<K, V>
where
K: Borrow<Q> + Hash + Eq + Ord,
Q: ?Sized + Hash + Eq + Ord,
{
type Output = V;
#[inline]
fn index(&self, key: &Q) -> &V {
&self.inner[key]
}
}
impl<K, V> Index<usize> for IndexMap<K, V>
where
K: Hash + Eq + Ord,
{
type Output = V;
#[inline]
fn index(&self, key: usize) -> &V {
&self.inner[key]
}
}
impl<K, V> Extend<(K, V)> for IndexMap<K, V>
where
K: Eq + Hash + Ord + Clone,
{
#[inline]
fn extend<Iter: IntoIterator<Item = (K, V)>>(&mut self, iter: Iter) {
self.inner.extend(iter)
}
}
/// A view into a single entry in a [`IndexMap`], which may either be vacant or occupied.
///
/// This enum is constructed from the entry method on [`IndexMap`].
#[derive(Debug)]
pub enum Entry<'a, K: Ord, V> {
/// An occupied entry.
Occupied(OccupiedEntry<'a, K, V>),
/// A vacant entry.
Vacant(VacantEntry<'a, K, V>),
}
impl<'a, K, V> Entry<'a, K, V>
where
K: Hash + Eq + Ord + Clone,
{
/// Returns a reference to this entry's key.
#[inline]
pub fn key(&self) -> &K {
match *self {
Self::Occupied(ref entry) => entry.key(),
Self::Vacant(ref entry) => entry.key(),
}
}
}
impl<'a, K, V> Entry<'a, K, V>
where
K: Hash + Eq + Ord + Clone,
V: Default,
{
/// Ensures a value is in the entry by inserting the default value if empty,
/// and returns a mutable reference to the value in the entry.
#[inline]
pub fn or_default(self) -> &'a mut V {
match self {
Self::Occupied(entry) => entry.into_mut(),
Self::Vacant(entry) => entry.insert(Default::default()),
}
}
}
/// A view into an occupied entry in a [`IndexMap`].
///
/// It is part of the [`Entry`] enum.
#[derive(Debug)]
pub struct OccupiedEntry<'a, K: Ord, V> {
inner: detail::OccupiedEntryImpl<'a, K, V>,
}
impl<'a, K: 'a, V: 'a> OccupiedEntry<'a, K, V>
where
K: Ord + Clone,
{
/// Gets a reference to the key in the entry.
#[inline]
pub fn key(&self) -> &K {
self.inner.key()
}
/// Gets a reference to the value in the entry.
#[inline]
pub fn get(&self) -> &V {
self.inner.get()
}
/// Gets a mutable reference to the value in the entry.
#[inline]
pub fn get_mut(&mut self) -> &mut V {
self.inner.get_mut()
}
/// Sets the value of the entry with the [`OccupiedEntry`]'s key, and returns the entry's old value.
#[inline]
pub fn insert(&mut self, value: V) -> V {
self.inner.insert(value)
}
/// Converts the [`OccupiedEntry`] into a mutable reference to the value in the entry
/// with a lifetime bound to the map itself.
#[inline]
pub fn into_mut(self) -> &'a mut V {
self.inner.into_mut()
}
}
/// A view into a vacant entry in a [`IndexMap`].
///
/// It is part of the [`Entry`] enum.
#[derive(Debug)]
pub struct VacantEntry<'a, K: Ord, V> {
inner: detail::VacantEntryImpl<'a, K, V>,
}
impl<'a, K: 'a, V: 'a> VacantEntry<'a, K, V>
where
K: Ord + Clone,
{
/// Gets a reference to the key in the entry.
#[inline]
pub fn key(&self) -> &K {
self.inner.key()
}
/// Take ownership of the key.
#[inline]
pub fn into_key(self) -> K {
self.inner.into_key()
}
/// Sets the value of the entry with the [`VacantEntry`]'s key, and returns a mutable reference to it.
#[inline]
pub fn insert(self, value: V) -> &'a mut V
where
K: Hash,
{
self.inner.insert(value)
}
}
impl<K, V> FromIterator<(K, V)> for IndexMap<K, V>
where
K: Hash + Ord + Eq + Clone,
{
#[inline]
fn from_iter<I>(iter: I) -> Self
where
I: IntoIterator<Item = (K, V)>,
{
Self {
inner: <detail::IndexMapImpl<K, V>>::from_iter(iter),
}
}
}
impl<'a, K, V> IntoIterator for &'a IndexMap<K, V> {
type Item = (&'a K, &'a V);
type IntoIter = Iter<'a, K, V>;
#[inline]
fn into_iter(self) -> Self::IntoIter {
self.iter()
}
}
/// An iterator over the items of a [`IndexMap`].
#[derive(Debug, Clone)]
pub struct Iter<'a, K, V> {
inner: detail::IterImpl<'a, K, V>,
}
impl<'a, K, V> Iterator for Iter<'a, K, V> {
type Item = (&'a K, &'a V);
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
#[inline]
fn next(&mut self) -> Option<Self::Item> {
self.inner.next()
}
}
impl<'a, K, V> ExactSizeIterator for Iter<'a, K, V> {
#[inline]
fn len(&self) -> usize {
self.inner.len()
}
}
impl<'a, K, V> FusedIterator for Iter<'a, K, V> {}
impl<'a, K, V> IntoIterator for &'a mut IndexMap<K, V> {
type Item = (&'a K, &'a mut V);
type IntoIter = IterMut<'a, K, V>;
#[inline]
fn into_iter(self) -> Self::IntoIter {
self.iter_mut()
}
}
/// An iterator over the mutable items of a [`IndexMap`].
#[derive(Debug)]
pub struct IterMut<'a, K, V> {
inner: detail::IterMutImpl<'a, K, V>,
}
impl<'a, K, V> Iterator for IterMut<'a, K, V> {
type Item = (&'a K, &'a mut V);
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
#[inline]
fn next(&mut self) -> Option<Self::Item> {
self.inner.next()
}
}
impl<'a, K, V> ExactSizeIterator for IterMut<'a, K, V> {
#[inline]
fn len(&self) -> usize {
self.inner.len()
}
}
impl<'a, K, V> FusedIterator for IterMut<'a, K, V> {}
impl<K, V> IntoIterator for IndexMap<K, V> {
type Item = (K, V);
type IntoIter = IntoIter<K, V>;
#[inline]
fn into_iter(self) -> Self::IntoIter {
IntoIter {
inner: self.inner.into_iter(),
}
}
}
/// An iterator over the owned items of an [`IndexMap`].
#[derive(Debug)]
pub struct IntoIter<K, V> {
inner: detail::IntoIterImpl<K, V>,
}
impl<'a, K, V> Iterator for IntoIter<K, V> {
type Item = (K, V);
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
#[inline]
fn next(&mut self) -> Option<Self::Item> {
self.inner.next()
}
}
impl<'a, K, V> ExactSizeIterator for IntoIter<K, V> {
#[inline]
fn len(&self) -> usize {
self.inner.len()
}
}
impl<'a, K, V> FusedIterator for IntoIter<K, V> {}
/// An iterator over the keys of a [`IndexMap`].
#[derive(Debug, Clone)]
pub struct Keys<'a, K, V> {
inner: detail::KeysImpl<'a, K, V>,
}
impl<'a, K, V> Iterator for Keys<'a, K, V> {
type Item = &'a K;
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
#[inline]
fn next(&mut self) -> Option<Self::Item> {
self.inner.next()
}
}
impl<'a, K, V> ExactSizeIterator for Keys<'a, K, V> {
#[inline]
fn len(&self) -> usize {
self.inner.len()
}
}
impl<'a, K, V> FusedIterator for Keys<'a, K, V> {}
/// An iterator over the values of a [`IndexMap`].
#[derive(Debug, Clone)]
pub struct Values<'a, K, V> {
inner: detail::ValuesImpl<'a, K, V>,
}
impl<'a, K, V> Iterator for Values<'a, K, V> {
type Item = &'a V;
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
#[inline]
fn next(&mut self) -> Option<Self::Item> {
self.inner.next()
}
}
impl<'a, K, V> ExactSizeIterator for Values<'a, K, V> {
#[inline]
fn len(&self) -> usize {
self.inner.len()
}
}
impl<'a, K, V> FusedIterator for Values<'a, K, V> {}
/// An mutable iterator over the values of a [`IndexMap`].
#[derive(Debug)]
pub struct ValuesMut<'a, K, V> {
inner: detail::ValuesMutImpl<'a, K, V>,
}
impl<'a, K, V> Iterator for ValuesMut<'a, K, V> {
type Item = &'a mut V;
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
#[inline]
fn next(&mut self) -> Option<Self::Item> {
self.inner.next()
}
}
impl<'a, K, V> ExactSizeIterator for ValuesMut<'a, K, V> {
#[inline]
fn len(&self) -> usize {
self.inner.len()
}
}
impl<'a, K, V> FusedIterator for ValuesMut<'a, K, V> {}
#[cfg(feature = "serde")]
impl<K, V> serde::Serialize for IndexMap<K, V>
where
K: serde::Serialize + Eq + Hash + Ord,
V: serde::Serialize,
{
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::ser::Serializer,
{
serde::Serialize::serialize(&self.inner, serializer)
}
}
#[cfg(feature = "serde")]
impl<'a, K, V> serde::Deserialize<'a> for IndexMap<K, V>
where
K: serde::Deserialize<'a> + Eq + Hash + Ord + Clone,
V: serde::Deserialize<'a>,
{
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: serde::de::Deserializer<'a>,
{
Ok(IndexMap {
inner: serde::Deserialize::deserialize(deserializer)?,
})
}
}
impl<K, V> PartialEq for IndexMap<K, V>
where
K: PartialEq + Hash + Ord,
V: PartialEq,
{
fn eq(&self, other: &Self) -> bool {
self.inner == other.inner
}
fn ne(&self, other: &Self) -> bool {
self.inner != other.inner
}
}
impl<K, V> Eq for IndexMap<K, V>
where
K: Eq + Hash + Ord,
V: Eq,
{
}