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//! An order-preserving immutable set constructed at compile time.
use crate::{ordered_map, OrderedMap, PhfHash};
use core::fmt;
use core::iter::FusedIterator;
use core::iter::IntoIterator;
use phf_shared::PhfBorrow;
/// An order-preserving immutable set constructed at compile time.
///
/// Unlike a `Set`, iteration order is guaranteed to match the definition
/// order.
///
/// ## Note
///
/// The fields of this struct are public so that they may be initialized by the
/// `phf_ordered_set!` macro and code generation. They are subject to change at
/// any time and should never be accessed directly.
pub struct OrderedSet<T: 'static> {
#[doc(hidden)]
pub map: OrderedMap<T, ()>,
}
impl<T> fmt::Debug for OrderedSet<T>
where
T: fmt::Debug,
{
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt.debug_set().entries(self).finish()
}
}
impl<T> OrderedSet<T> {
/// Returns the number of elements in the `OrderedSet`.
#[inline]
pub const fn len(&self) -> usize {
self.map.len()
}
/// Returns true if the `OrderedSet` contains no elements.
#[inline]
pub const fn is_empty(&self) -> bool {
self.len() == 0
}
/// Returns a reference to the set's internal static instance of the given
/// key.
///
/// This can be useful for interning schemes.
pub fn get_key<U: ?Sized>(&self, key: &U) -> Option<&T>
where
U: Eq + PhfHash,
T: PhfBorrow<U>,
{
self.map.get_key(key)
}
/// Returns the index of the key within the list used to initialize
/// the ordered set.
pub fn get_index<U: ?Sized>(&self, key: &U) -> Option<usize>
where
U: Eq + PhfHash,
T: PhfBorrow<U>,
{
self.map.get_index(key)
}
/// Returns a reference to the key at an index
/// within the list used to initialize the ordered set. See `.get_index(key)`.
pub fn index(&self, index: usize) -> Option<&T> {
self.map.index(index).map(|(k, &())| k)
}
/// Returns true if `value` is in the `OrderedSet`.
pub fn contains<U: ?Sized>(&self, value: &U) -> bool
where
U: Eq + PhfHash,
T: PhfBorrow<U>,
{
self.map.contains_key(value)
}
/// Returns an iterator over the values in the set.
///
/// Values are returned in the same order in which they were defined.
pub fn iter(&self) -> Iter<'_, T> {
Iter {
iter: self.map.keys(),
}
}
}
impl<T> OrderedSet<T>
where
T: Eq + PhfHash + PhfBorrow<T>,
{
/// Returns true if `other` shares no elements with `self`.
#[inline]
pub fn is_disjoint(&self, other: &OrderedSet<T>) -> bool {
!self.iter().any(|value| other.contains(value))
}
/// Returns true if `other` contains all values in `self`.
#[inline]
pub fn is_subset(&self, other: &OrderedSet<T>) -> bool {
self.iter().all(|value| other.contains(value))
}
/// Returns true if `self` contains all values in `other`.
#[inline]
pub fn is_superset(&self, other: &OrderedSet<T>) -> bool {
other.is_subset(self)
}
}
impl<'a, T> IntoIterator for &'a OrderedSet<T> {
type Item = &'a T;
type IntoIter = Iter<'a, T>;
fn into_iter(self) -> Iter<'a, T> {
self.iter()
}
}
/// An iterator over the values in a `OrderedSet`.
pub struct Iter<'a, T> {
iter: ordered_map::Keys<'a, T, ()>,
}
impl<'a, T> Clone for Iter<'a, T> {
#[inline]
fn clone(&self) -> Self {
Self {
iter: self.iter.clone(),
}
}
}
impl<'a, T> fmt::Debug for Iter<'a, T>
where
T: fmt::Debug,
{
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_list().entries(self.clone()).finish()
}
}
impl<'a, T> Iterator for Iter<'a, T> {
type Item = &'a T;
#[inline]
fn next(&mut self) -> Option<&'a T> {
self.iter.next()
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
impl<'a, T> DoubleEndedIterator for Iter<'a, T> {
#[inline]
fn next_back(&mut self) -> Option<&'a T> {
self.iter.next_back()
}
}
impl<'a, T> ExactSizeIterator for Iter<'a, T> {}
impl<'a, T> FusedIterator for Iter<'a, T> {}