1 files changed, 170 insertions, 0 deletions
diff --git a/third_party/rust/phf/src/ordered_set.rs b/third_party/rust/phf/src/ordered_set.rs
new file mode 100644
index 0000000000..e85d45711f
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+++ b/third_party/rust/phf/src/ordered_set.rs
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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> {}