Struct elsa::map::FrozenMap

pub struct FrozenMap<K, V, S = RandomState> { /* private fields */ }

Append-only version of std::collections::HashMap where insertion does not require mutable access

Implementations

impl<K: Eq + Hash, V> FrozenMap<K, V>

pub fn new() -> Self

pub fn len(&self) -> usize

Examples

use elsa::FrozenMap;

let map = FrozenMap::new();
assert_eq!(map.len(), 0);
map.insert(1, Box::new("a"));
assert_eq!(map.len(), 1);

pub fn is_empty(&self) -> bool

Examples

use elsa::FrozenMap;

let map = FrozenMap::new();
assert_eq!(map.is_empty(), true);
map.insert(1, Box::new("a"));
assert_eq!(map.is_empty(), false);

impl<K: Eq + Hash, V: StableDeref, S: BuildHasher> FrozenMap<K, V, S>

pub fn insert(&self, k: K, v: V) -> &V::Target

pub fn get<Q>(&self, k: &Q) -> Option<&V::Target>where K: Borrow<Q>, Q: Hash + Eq + ?Sized,

Returns a reference to the value corresponding to the key.

The key may be any borrowed form of the map’s key type, but Hash and Eq on the borrowed form must match those for the key type.

Examples

use elsa::FrozenMap;

let map = FrozenMap::new();
map.insert(1, Box::new("a"));
assert_eq!(map.get(&1), Some(&"a"));
assert_eq!(map.get(&2), None);

pub fn map_get<Q, T, F>(&self, k: &Q, f: F) -> Option<T>where K: Borrow<Q>, Q: Hash + Eq + ?Sized, F: FnOnce(&V) -> T,

Applies a function to the owner of the value corresponding to the key (if any).

The key may be any borrowed form of the map’s key type, but Hash and Eq on the borrowed form must match those for the key type.

Examples

use elsa::FrozenMap;

let map = FrozenMap::new();
map.insert(1, Box::new("a"));
assert_eq!(map.map_get(&1, Clone::clone), Some(Box::new("a")));
assert_eq!(map.map_get(&2, Clone::clone), None);

impl<K, V, S> FrozenMap<K, V, S>

pub fn into_tuple_vec(self) -> Vec<(K, V)>

Collects the contents of this map into a vector of tuples.

The order of the entries is as if iterating a HashMap (stochastic).

Examples

use elsa::FrozenMap;

let map = FrozenMap::new();
map.insert(1, Box::new("a"));
map.insert(2, Box::new("b"));
let mut tuple_vec = map.into_tuple_vec();
tuple_vec.sort();

assert_eq!(tuple_vec, vec![(1, Box::new("a")), (2, Box::new("b"))]);

pub fn into_map(self) -> HashMap<K, V, S>

impl<K: Eq + Hash + StableDeref, V: StableDeref, S: BuildHasher> FrozenMap<K, V, S>

pub fn get_key_value<Q>(&self, k: &Q) -> Option<(&K::Target, &V::Target)>where K: Borrow<Q>, Q: Hash + Eq + ?Sized,

Returns a reference to the key and value matching a borrowed key.

The key argument may be any borrowed form of the map’s key type, but Hash and Eq on the borrowed form must match those for the key type.

Examples

use elsa::FrozenMap;

let map = FrozenMap::new();
map.insert(Box::new("1"), Box::new("a"));
assert_eq!(map.get_key_value(&"1"), Some((&"1", &"a")));
assert_eq!(map.get_key_value(&"2"), None);

Trait Implementations

impl<K, V, S> AsMut<HashMap<K, V, S>> for FrozenMap<K, V, S>

fn as_mut(&mut self) -> &mut HashMap<K, V, S>

Get mutable access to the underlying HashMap.

This is safe, as it requires a &mut self, ensuring nothing is using the ‘frozen’ contents.

impl<K: Clone, V: Clone, S: Clone> Clone for FrozenMap<K, V, S>

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<K: Eq + Hash, V, S: Default> Default for FrozenMap<K, V, S>

fn default() -> Self

Returns the “default value” for a type.

impl<K, V, S> From<HashMap<K, V, S>> for FrozenMap<K, V, S>

fn from(map: HashMap<K, V, S>) -> Self

Converts to this type from the input type.

impl<K: Eq + Hash, V, S: BuildHasher + Default> FromIterator<(K, V)> for FrozenMap<K, V, S>

fn from_iter<T>(iter: T) -> Selfwhere T: IntoIterator<Item = (K, V)>,

Creates a value from an iterator.

impl<Q, K, V, S> Index<&Q> for FrozenMap<K, V, S>where Q: Eq + Hash + ?Sized, K: Eq + Hash + Borrow<Q>, V: StableDeref, S: BuildHasher,

fn index(&self, idx: &Q) -> &V::Target

Examples

use elsa::FrozenMap;

let map = FrozenMap::new();
map.insert(1, Box::new("a"));
assert_eq!(map[&1], "a");

type Output = <V as Deref>::Target

The returned type after indexing.

impl<K: Eq + Hash, V: PartialEq + StableDeref> PartialEq<FrozenMap<K, V, RandomState>> for FrozenMap<K, V>

fn eq(&self, other: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.