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// altered from HashMap
use core::marker;
use std::borrow::Borrow;
#[allow(unused_imports)]
use super::pervasive::*;
use super::prelude::*;
#[allow(unused_imports)]
use super::set::*;
#[cfg(verus_keep_ghost)]
use super::std_specs::hash::obeys_key_model;
#[allow(unused_imports)]
use core::hash::Hash;
use std::collections::HashSet;
verus! {
/// `HashSetWithView` is a trusted wrapper around `std::collections::HashSet` with `View` implemented for the type `vstd::map::Set<<Key as View>::V>`.
///
/// See the Rust documentation for [`HashSet`](https://doc.rust-lang.org/std/collections/struct.HashSet.html)
/// for details about its implementation.
///
/// If you are using `std::collections::HashSet` directly, see [`ExHashSet`](https://verus-lang.github.io/verus/verusdoc/vstd/std_specs/hash/struct.ExHashSet.html)
/// for information on the Verus specifications for this type.
#[verifier::ext_equal]
#[verifier::reject_recursive_types(Key)]
pub struct HashSetWithView<Key> where Key: View + Eq + Hash {
m: HashSet<Key>,
}
impl<Key> View for HashSetWithView<Key> where Key: View + Eq + Hash {
type V = Set<<Key as View>::V>;
uninterp spec fn view(&self) -> Self::V;
}
impl<Key> HashSetWithView<Key> where Key: View + Eq + Hash {
/// Creates an empty `HashSetWithView` with capacity 0.
///
/// See [`obeys_key_model()`](https://verus-lang.github.io/verus/verusdoc/vstd/std_specs/hash/fn.obeys_key_model.html)
/// for information on use with primitive types and other types.
/// See Rust's [`HashSet::new()`](https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.new) for implementation details.
#[verifier::external_body]
pub fn new() -> (result: Self)
requires
obeys_key_model::<Key>(),
forall|k1: Key, k2: Key| k1@ == k2@ ==> k1 == k2,
ensures
result@ == Set::<<Key as View>::V>::empty(),
{
Self { m: HashSet::new() }
}
/// Creates an empty `HashSetWithView` with at least capacity for the specified number of elements.
///
/// See [`obeys_key_model()`](https://verus-lang.github.io/verus/verusdoc/vstd/std_specs/hash/fn.obeys_key_model.html)
/// for information on use with primitive types and other types.
/// See Rust's [`HashSet::with_capacity()`](https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.with_capacity) for implementation details.
#[verifier::external_body]
pub fn with_capacity(capacity: usize) -> (result: Self)
requires
obeys_key_model::<Key>(),
forall|k1: Key, k2: Key| k1@ == k2@ ==> k1 == k2,
ensures
result@ == Set::<<Key as View>::V>::empty(),
{
Self { m: HashSet::with_capacity(capacity) }
}
/// Reserves capacity for at least `additional` number of elements in the set.
///
/// See Rust's [`HashSet::reserve()`](https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.reserve) for implementation details.
#[verifier::external_body]
pub fn reserve(&mut self, additional: usize)
ensures
self@ == old(self)@,
{
self.m.reserve(additional);
}
/// Returns the number of elements in the set.
pub uninterp spec fn spec_len(&self) -> usize;
/// Returns the number of elements in the set.
#[verifier::external_body]
#[verifier::when_used_as_spec(spec_len)]
pub fn len(&self) -> (result: usize)
ensures
result == self@.len(),
{
self.m.len()
}
/// Returns true if the set is empty.
#[verifier::external_body]
pub fn is_empty(&self) -> (result: bool)
ensures
result == self@.is_empty(),
{
self.m.is_empty()
}
/// Inserts the given value into the set. Returns true if the value was not previously in the set, false otherwise.
///
/// See Rust's [`HashSet::insert()`](https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.insert) for implementation details.
#[verifier::external_body]
pub fn insert(&mut self, k: Key) -> (result: bool)
ensures
self@ == old(self)@.insert(k@) && result == !old(self)@.contains(k@),
{
self.m.insert(k)
}
/// Removes the given value from the set. Returns true if the value was previously in the set, false otherwise.
///
/// See Rust's [`HashSet::remove()`](https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.remove) for implementation details.
#[verifier::external_body]
pub fn remove(&mut self, k: &Key) -> (result: bool)
ensures
self@ == old(self)@.remove(k@) && result == old(self)@.contains(k@),
{
self.m.remove(k)
}
/// Returns true if the set contains the given value.
///
/// See Rust's [`HashSet::contains()`](https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.contains) for implementation details.
#[verifier::external_body]
pub fn contains(&self, k: &Key) -> (result: bool)
ensures
result == self@.contains(k@),
{
self.m.contains(k)
}
/// Returns a reference to the value in the set that is equal to the given value. If the value is not present in the set, returns `None`.
///
/// See Rust's [`HashSet::get()`](https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.get) for implementation details.
#[verifier::external_body]
pub fn get<'a>(&'a self, k: &Key) -> (result: Option<&'a Key>)
ensures
match result {
Some(v) => self@.contains(k@) && v == &k,
None => !self@.contains(k@),
},
{
self.m.get(k)
}
/// Clears all values from the set.
///
/// See Rust's [`HashSet::clear()`](https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.clear) for implementation details.
#[verifier::external_body]
pub fn clear(&mut self)
ensures
self@ == Set::<<Key as View>::V>::empty(),
{
self.m.clear()
}
}
pub broadcast axiom fn axiom_hash_set_with_view_spec_len<Key>(m: &HashSetWithView<Key>) where
Key: View + Eq + Hash,
ensures
#[trigger] m.spec_len() == m@.len(),
;
/// `StringHashSet` is a trusted wrapper around `std::collections::HashSet<String>` with `View` implemented for the type `vstd::map::Set<Seq<char>>`.
///
/// This type was created for ease of use with `String` as it uses `&str` instead of `&String` for methods that require shared references.
/// Also, it assumes that [`obeys_key_model::<String>()`](https://verus-lang.github.io/verus/verusdoc/vstd/std_specs/hash/fn.obeys_key_model.html) holds.
///
/// See the Rust documentation for [`HashSet`](https://doc.rust-lang.org/std/collections/struct.HashSet.html)
/// for details about its implementation.
///
/// If you are using `std::collections::HashSet` directly, see [`ExHashSet`](https://verus-lang.github.io/verus/verusdoc/vstd/std_specs/hash/struct.ExHashSet.html)
/// for information on the Verus specifications for this type.
#[verifier::ext_equal]
pub struct StringHashSet {
m: HashSet<String>,
}
impl View for StringHashSet {
type V = Set<Seq<char>>;
uninterp spec fn view(&self) -> Self::V;
}
impl StringHashSet {
/// Creates an empty `StringHashSet` with capacity 0.
///
/// See Rust's [`HashSet::new()`](https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.new) for implementation details.
#[verifier::external_body]
pub fn new() -> (result: Self)
ensures
result@ == Set::<Seq<char>>::empty(),
{
Self { m: HashSet::new() }
}
/// Creates an empty `StringHashSet` with at least capacity for the specified number of elements.
///
/// See Rust's [`HashSet::with_capacity()`](https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.with_capacity) for implementation details.
#[verifier::external_body]
pub fn with_capacity(capacity: usize) -> (result: Self)
ensures
result@ == Set::<Seq<char>>::empty(),
{
Self { m: HashSet::with_capacity(capacity) }
}
/// Reserves capacity for at least `additional` number of elements in the set.
///
/// See Rust's [`HashSet::reserve()`](https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.reserve) for implementation details.
#[verifier::external_body]
pub fn reserve(&mut self, additional: usize)
ensures
self@ == old(self)@,
{
self.m.reserve(additional);
}
/// Returns true if the set is empty.
#[verifier::external_body]
pub fn is_empty(&self) -> (result: bool)
ensures
result == self@.is_empty(),
{
self.m.is_empty()
}
/// Returns the number of elements in the set.
pub uninterp spec fn spec_len(&self) -> usize;
/// Returns the number of elements in the set.
#[verifier::external_body]
#[verifier::when_used_as_spec(spec_len)]
pub fn len(&self) -> (result: usize)
ensures
result == self@.len(),
{
self.m.len()
}
/// Inserts the given value into the set. Returns true if the value was not previously in the set, false otherwise.
///
/// See Rust's [`HashSet::insert()`](https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.insert) for implementation details.
#[verifier::external_body]
pub fn insert(&mut self, k: String) -> (result: bool)
ensures
self@ == old(self)@.insert(k@) && result == !old(self)@.contains(k@),
{
self.m.insert(k)
}
/// Removes the given value from the set. Returns true if the value was previously in the set, false otherwise.
///
/// See Rust's [`HashSet::remove()`](https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.remove) for implementation details.
#[verifier::external_body]
pub fn remove(&mut self, k: &str) -> (result: bool)
ensures
self@ == old(self)@.remove(k@) && result == old(self)@.contains(k@),
{
self.m.remove(k)
}
/// Returns true if the set contains the given value.
///
/// See Rust's [`HashSet::contains()`](https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.contains) for implementation details.
#[verifier::external_body]
pub fn contains(&self, k: &str) -> (result: bool)
ensures
result == self@.contains(k@),
{
self.m.contains(k)
}
/// Returns a reference to the value in the set that is equal to the given value. If the value is not present in the set, returns `None`.
///
/// See Rust's [`HashSet::get()`](https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.get) for implementation details.
#[verifier::external_body]
pub fn get<'a>(&'a self, k: &str) -> (result: Option<&'a String>)
ensures
match result {
Some(v) => self@.contains(k@) && v@ == k@,
None => !self@.contains(k@),
},
{
self.m.get(k)
}
/// Clears all values from the set.
///
/// See Rust's [`HashSet::clear()`](https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.clear) for implementation details.
#[verifier::external_body]
pub fn clear(&mut self)
ensures
self@ == Set::<Seq<char>>::empty(),
{
self.m.clear()
}
}
pub broadcast axiom fn axiom_string_hash_set_spec_len(m: &StringHashSet)
ensures
#[trigger] m.spec_len() == m@.len(),
;
pub broadcast group group_hash_set_axioms {
axiom_hash_set_with_view_spec_len,
axiom_string_hash_set_spec_len,
}
} // verus!