cairo_lang_utils/
unordered_hash_set.rs

1use core::borrow::Borrow;
2use core::hash::{BuildHasher, Hash};
3use core::ops::Sub;
4#[cfg(feature = "std")]
5use std::collections::HashSet;
6#[cfg(feature = "std")]
7use std::collections::hash_map::RandomState;
8
9#[cfg(not(feature = "std"))]
10use hashbrown::HashSet;
11
12/// A hash set that does not care about the order of insertion.
13///
14/// In particular, it does not support iterating, in order to guarantee deterministic compilation.
15/// For an iterable version see [OrderedHashSet](crate::ordered_hash_set::OrderedHashSet).
16#[cfg(feature = "std")]
17#[derive(Clone, Debug)]
18pub struct UnorderedHashSet<Key, BH = RandomState>(HashSet<Key, BH>);
19#[cfg(not(feature = "std"))]
20#[derive(Clone, Debug)]
21pub struct UnorderedHashSet<Key, BH = hashbrown::DefaultHashBuilder>(HashSet<Key, BH>);
22
23// This code was taken from the salsa::Update trait implementation for IndexSet.
24// It is defined privately in macro_rules! maybe_update_set in the db-ext-macro repo (with a small
25// change of using `extend_unordered` instead of `extend`).
26#[cfg(feature = "salsa")]
27unsafe impl<Key: Eq + Hash, BH: BuildHasher> salsa::Update for UnorderedHashSet<Key, BH> {
28    unsafe fn maybe_update(old_pointer: *mut Self, new_set: Self) -> bool {
29        let old_set: &mut Self = unsafe { &mut *old_pointer };
30
31        if *old_set == new_set {
32            false
33        } else {
34            old_set.clear();
35            old_set.extend_unordered(new_set);
36            true
37        }
38    }
39}
40
41impl<K, BH: Default> Default for UnorderedHashSet<K, BH> {
42    #[cfg(feature = "std")]
43    fn default() -> Self {
44        Self(Default::default())
45    }
46    #[cfg(not(feature = "std"))]
47    fn default() -> Self {
48        Self(HashSet::with_hasher(Default::default()))
49    }
50}
51
52impl<K, BH> PartialEq for UnorderedHashSet<K, BH>
53where
54    K: Eq + Hash,
55    BH: BuildHasher,
56{
57    fn eq(&self, other: &Self) -> bool {
58        self.0 == other.0
59    }
60}
61
62impl<K, BH> Eq for UnorderedHashSet<K, BH>
63where
64    K: Eq + Hash,
65    BH: BuildHasher,
66{
67}
68
69impl<Key, BH> UnorderedHashSet<Key, BH> {
70    /// Returns the number of elements in the set.
71    pub fn len(&self) -> usize {
72        self.0.len()
73    }
74
75    /// Returns true if the set contains no elements.
76    pub fn is_empty(&self) -> bool {
77        self.0.is_empty()
78    }
79
80    /// Clears the set, removing all values.
81    pub fn clear(&mut self) {
82        self.0.clear()
83    }
84}
85
86impl<Key: Hash + Eq, BH: BuildHasher> UnorderedHashSet<Key, BH> {
87    /// Inserts the value into the set.
88    ///
89    /// If an equivalent item already exists in the set, returns `false`. Otherwise, returns `true`.
90    pub fn insert(&mut self, key: Key) -> bool {
91        self.0.insert(key)
92    }
93
94    /// Removes a value from the set. Returns whether the value was present in the set.
95    pub fn remove<Q: ?Sized + Hash + Eq>(&mut self, value: &Q) -> bool
96    where
97        Key: Borrow<Q>,
98    {
99        self.0.remove(value)
100    }
101
102    /// Extends the set with the content of the given iterator.
103    pub fn extend<I: IntoIterator<Item = Key>>(&mut self, iter: I) {
104        self.0.extend(iter)
105    }
106
107    /// Extends the set with the content of another set.
108    pub fn extend_unordered(&mut self, other: Self) {
109        self.0.extend(other.0)
110    }
111
112    /// Returns true if an equivalent to value exists in the set.
113    pub fn contains<Q: ?Sized + Hash + Eq>(&self, value: &Q) -> bool
114    where
115        Key: Borrow<Q>,
116    {
117        self.0.contains(value)
118    }
119}
120
121impl<Key: Hash + Eq, BH: BuildHasher + Default> FromIterator<Key> for UnorderedHashSet<Key, BH> {
122    fn from_iter<T: IntoIterator<Item = Key>>(iter: T) -> Self {
123        Self(iter.into_iter().collect())
124    }
125}
126
127impl<'a, Key, BH> Sub<&'a UnorderedHashSet<Key, BH>> for &'a UnorderedHashSet<Key, BH>
128where
129    &'a HashSet<Key, BH>: Sub<Output = HashSet<Key, BH>>,
130{
131    type Output = UnorderedHashSet<Key, BH>;
132
133    fn sub(self, rhs: Self) -> Self::Output {
134        UnorderedHashSet::<Key, BH>(&self.0 - &rhs.0)
135    }
136}
cairo_lang_utils/unordered_hash_set.rs

cairo_lang_utils/
unordered_hash_set.rs
