core:collections
Maps and sets that iterate in insertion order. TreeMap<K, V> and
TreeSet<T> find a key by ordering it; HashMap<K, V> and HashSet<T> by
hashing it under a HashSeed. map[key] = value overwrites; try_insert /
get_or_insert insert only when the key is absent.
Synopsis
let mut sizes = { small: 1, medium: 2, large: 3 } as TreeMap<String, i32>;
assert sizes.len() == 3;
assert sizes["medium"] == 2;
assert sizes.get("small") matches { Some(v) && v == 1 };
sizes["xlarge"] = 4;
assert sizes.len() == 4;
let primes = [7, 2, 5, 2, 3] as TreeSet<i32>;
assert primes.len() == 4;
assert primes.contains(5);
assert !primes.contains(4);
let mut seen = HashSet::<String>::new();
assert seen.insert("b");
assert seen.insert("a");
assert !seen.insert("b");
assert seen.iter_value().collect() == ["b", "a"];
Structs
pub struct MapKeysRefIter<K, V>
A map's keys, or a set's elements, by reference.
Fields are private.
pub fn iter_value(&self) -> MapKeysValueIter<K, V>
impl Iterator for MapKeysRefIter<K, V>
fn next(&mut self) -> Option<&K>
pub struct MapKeysValueIter<K, V>
A map's keys, or a set's elements, by value.
Fields are private.
impl Iterator for MapKeysValueIter<K, V>
fn next(&mut self) -> Option<K>
pub struct MapValuesRefIter<K, V>
A map's values, by reference.
Fields are private.
pub fn iter_value(&self) -> MapValuesValueIter<K, V>
impl Iterator for MapValuesRefIter<K, V>
fn next(&mut self) -> Option<&V>
pub struct MapValuesValueIter<K, V>
A map's values, by value. The doubled word is the axis meeting a
projection already named values.
Fields are private.
impl Iterator for MapValuesValueIter<K, V>
fn next(&mut self) -> Option<V>
pub struct MapEntriesRefIter<K, V>
A map's key-value pairs, by reference.
Fields are private.
pub fn iter_value(&self) -> MapEntriesValueIter<K, V>
impl Iterator for MapEntriesRefIter<K, V>
fn next(&mut self) -> Option<[&K, &V]>
#[compiler_item("map_entries_iter_next")]
pub struct MapEntriesValueIter<K, V>
A map's key-value pairs, by value.
Fields are private.
impl Iterator for MapEntriesValueIter<K, V>
fn next(&mut self) -> Option<[K, V]>
pub struct TreeMap<K, V>
A map that iterates in insertion order.
Keys are stored in a tree for O(log n) lookups, while key-value pairs are stored in a dense array for fast, insertion-order iteration.
This is similar to Rust's indexmap::IndexMap but uses a tree instead
of a hash table for key lookups.
Fields are private.
pub fn new() -> TreeMap<K, V>
#[compiler_item("tree_map_new")]
Creates a new empty TreeMap.
pub fn len(&self) -> i32
#[compiler_item("tree_map_len")]
Returns the number of key-value pairs in the map.
pub fn is_empty(&self) -> bool
Returns true if the map contains no elements.
pub fn try_insert(&mut self, key: K, value: V) -> bool
Inserts only if key is absent, and reports whether it was inserted.
The losing insert keeps the existing value, unlike map[key] = value.
pub fn get_or_insert(&mut self, key: K, value: V) -> V
The value already stored under key, or value inserted and returned.
The shape of TC39's Map.prototype.getOrInsert; for whether it
inserted, use try_insert.
pub fn contains_key(&self, key: K) -> bool
Returns true if the map contains a value for the specified key.
pub fn get(&self, key: K) -> Option<V>
Returns the value corresponding to the key, or null if not found.
pub fn remove(&mut self, key: K) -> bool
Removes a key from the map and returns true if the key was present. Preserves insertion order of remaining elements.
pub fn keys(&self) -> MapKeysRefIter<K, V>
The keys, in insertion order. A map traversal yields references and
carries no axis suffix: keys already says what it yields, and a
caller wanting owned keys takes iter_value() off the result.
pub fn values(&self) -> MapValuesRefIter<K, V>
The values, in insertion order.
pub fn entries(&self) -> MapEntriesRefIter<K, V>
#[compiler_item("tree_map_entries")]
The key-value pairs, in insertion order.
pub fn clear(&mut self)
Removes all key-value pairs from the map.
pub fn get_str<S: AsStrSlice>(&self, key: S) -> Option<V>
Returns the value stored under text equal to key, or null.
pub fn contains_key_str<S: AsStrSlice>(&self, key: S) -> bool
Returns true if some key spells the same text as key.
pub fn get_ref_str<S: AsStrSlice>(&self, key: S) -> Option<&V>
Returns a reference to the value stored under text equal to key.
impl Eq for TreeMap<K, V>
fn eq(&self, other: &TreeMap<K, V>) -> bool
impl Ord for TreeMap<K, V>
fn cmp(&self, other: &TreeMap<K, V>) -> Ordering
impl IndexAssign<K> for TreeMap<K, V>
fn index_assign(&mut self, key: K, value: Self::Output)
#[compiler_item("tree_map_index_assign")]
impl IndexValue<K> for TreeMap<K, V>
fn index_value(&self, key: K) -> Self::Output
impl IndexRef<K> for TreeMap<K, V>
fn index_ref(&self, key: K) -> &V
impl IndexRefMut<K> for TreeMap<K, V>
fn index_ref_mut(&mut self, key: K) -> &mut V
impl From<Array<[String, V]>> for TreeMap<String, V>
fn from(entries: Array<[String, V]>) -> TreeMap<String, V>
impl LiteralSpread for TreeMap<String, V>
fn spread_literal(&mut self, base: TreeMap<String, V>)
impl Serialize for TreeMap<K, V>
fn serialize<S: Serializer>(&self, s: &mut S) -> Result<(), SerializeError>
impl Deserialize for TreeMap<K, V>
fn deserialize<D: Deserializer>(d: &mut D) -> Result<TreeMap<K, V>, DeserializeError>
impl Inspect for TreeMap<K, V>
pub fn inspect(&self, f: &mut Formatter)
impl Default for TreeMap<K, V>
pub fn default() -> TreeMap<K, V>
pub struct TreeSet<T>
A set that iterates in insertion order.
Backed by a TreeMap<T, ()>, which keeps a B-tree for O(log n) membership
tests and a dense array for O(1) insertion-order iteration.
Duplicate inserts are silently ignored (preserving the original position). Removing an element and re-inserting it appends it at the end.
T must implement Ord to use any of the methods.
Fields are private.
pub fn new() -> TreeSet<T>
Creates a new empty TreeSet.
pub fn len(&self) -> i32
Returns the number of elements in the set.
pub fn is_empty(&self) -> bool
Returns true if the set contains no elements.
pub fn insert(&mut self, value: T) -> bool
Inserts a value into the set.
Returns true if the value was newly inserted, false if it was already present.
pub fn contains(&self, value: T) -> bool
Returns true if the set contains the given value.
pub fn remove(&mut self, value: T) -> bool
Removes a value from the set.
Returns true if the value was present, false otherwise.
pub fn clear(&mut self)
Removes all elements from the set.
pub fn iter_ref(&self) -> MapKeysRefIter<T, ()>
The elements, in insertion order.
pub fn iter_value(&self) -> MapKeysValueIter<T, ()>
The elements, in insertion order.
pub fn contains_str<S: AsStrSlice>(&self, value: S) -> bool
Returns true if some element spells the same text as value.
impl IntoIterator for TreeSet<T>
fn into_iter(&self) -> MapKeysValueIter<T, ()>
impl From<Array<T>> for TreeSet<T>
fn from(elements: Array<T>) -> TreeSet<T>
impl Serialize for TreeSet<T>
fn serialize<S: Serializer>(&self, s: &mut S) -> Result<(), SerializeError>
impl Deserialize for TreeSet<T>
fn deserialize<D: Deserializer>(d: &mut D) -> Result<TreeSet<T>, DeserializeError>
impl Inspect for TreeSet<T>
pub fn inspect(&self, f: &mut Formatter)
impl Default for TreeSet<T>
pub fn default() -> TreeSet<T>
pub struct HashSeed
The key to a HashMap's hash function. A seed nobody outside the program
can predict keeps keys an attacker chooses from colliding.
Fields are private.
pub fn fixed(k0: u64, k1: u64) -> HashSeed
A seed of the caller's choosing, for a map whose keys the program trusts and whose hashing must be the same on every run.
pub struct HashMap<K, V>
A map that iterates in insertion order, found by hashing its keys.
Its hash function is keyed by a HashSeed: the host's under new(), which
holds up against keys an attacker chooses, or the caller's under
with_seed.
Fields are private.
pub fn new() -> HashMap<K, V>
An empty map hashing under the host's seed.
pub fn with_seed(seed: HashSeed) -> HashMap<K, V>
An empty map hashing with seed.
pub fn len(&self) -> i32
Returns the number of key-value pairs in the map.
pub fn is_empty(&self) -> bool
Returns true if the map contains no elements.
pub fn try_insert(&mut self, key: K, value: V) -> bool
Inserts only if key is absent, and reports whether it was inserted.
The losing insert keeps the existing value, unlike map[key] = value.
pub fn get_or_insert(&mut self, key: K, value: V) -> V
The value already stored under key, or value inserted and returned.
pub fn contains_key(&self, key: K) -> bool
Returns true if the map contains a value for the specified key.
pub fn get(&self, key: K) -> Option<V>
Returns the value corresponding to the key, or null if not found.
pub fn remove(&mut self, key: K) -> bool
Removes a key from the map and returns true if the key was present. Preserves insertion order of remaining elements.
pub fn keys(&self) -> MapKeysRefIter<K, V>
The keys, in insertion order.
pub fn values(&self) -> MapValuesRefIter<K, V>
The values, in insertion order.
pub fn entries(&self) -> MapEntriesRefIter<K, V>
The key-value pairs, in insertion order.
pub fn clear(&mut self)
Removes all key-value pairs from the map. The seed stays.
pub fn get_str<S: AsStrSlice>(&self, key: S) -> Option<V>
Returns the value stored under text equal to key, or null.
pub fn contains_key_str<S: AsStrSlice>(&self, key: S) -> bool
Returns true if some key spells the same text as key.
pub fn get_ref_str<S: AsStrSlice>(&self, key: S) -> Option<&V>
Returns a reference to the value stored under text equal to key.
impl Eq for HashMap<K, V>
fn eq(&self, other: &HashMap<K, V>) -> bool
impl Ord for HashMap<K, V>
fn cmp(&self, other: &HashMap<K, V>) -> Ordering
impl Inspect for HashMap<K, V>
fn inspect(&self, f: &mut Formatter)
impl IndexAssign<K> for HashMap<K, V>
fn index_assign(&mut self, key: K, value: Self::Output)
impl IndexValue<K> for HashMap<K, V>
fn index_value(&self, key: K) -> Self::Output
impl IndexRef<K> for HashMap<K, V>
fn index_ref(&self, key: K) -> &V
impl IndexRefMut<K> for HashMap<K, V>
fn index_ref_mut(&mut self, key: K) -> &mut V
impl From<Array<[String, V]>> for HashMap<String, V>
fn from(entries: Array<[String, V]>) -> HashMap<String, V>
impl LiteralSpread for HashMap<String, V>
fn spread_literal(&mut self, base: HashMap<String, V>)
impl Default for HashMap<K, V>
fn default() -> HashMap<K, V>
impl Serialize for HashMap<K, V>
fn serialize<S: Serializer>(&self, s: &mut S) -> Result<(), SerializeError>
impl Deserialize for HashMap<K, V>
fn deserialize<D: Deserializer>(d: &mut D) -> Result<HashMap<K, V>, DeserializeError>
pub struct HashSet<T>
A set that iterates in insertion order, found by hashing its elements.
Fields are private.
pub fn new() -> HashSet<T>
An empty set hashing under the host's seed.
pub fn with_seed(seed: HashSeed) -> HashSet<T>
An empty set hashing with seed.
pub fn len(&self) -> i32
Returns the number of elements in the set.
pub fn is_empty(&self) -> bool
Returns true if the set contains no elements.
pub fn insert(&mut self, value: T) -> bool
Inserts a value, and reports whether it was absent.
pub fn contains(&self, value: T) -> bool
Returns true if the set contains the given value.
pub fn remove(&mut self, value: T) -> bool
Removes a value, and reports whether it was present.
pub fn clear(&mut self)
Removes all elements from the set.
pub fn iter_ref(&self) -> MapKeysRefIter<T, ()>
The elements, in insertion order.
pub fn iter_value(&self) -> MapKeysValueIter<T, ()>
The elements, in insertion order.
pub fn contains_str<S: AsStrSlice>(&self, value: S) -> bool
Returns true if some element spells the same text as value.