Class in collections::map coil-stdlib

`HashMap`

class HashMap<K, V>

Import

use collections::map::{HashMap};

Source: src/collections/map.hy

A hash map from keys of type K to values of type V.

Keys need Eq and Hash (the primitive types have both; #[derive(Eq, Hash)] adds them to your own types). Inserting an existing key replaces its value. Iteration (for e in m, m.keys(), m.values()) visits entries in insertion order, skipping removed ones.

get takes a fallback instead of returning an Option; use contains first when the fallback could be a real value.

Fields#

Field	Type	Description
`keys`	`Vec<K>`	Key slots, including removed ones (see `live`). Prefer `keys()`.
`vals`	`Vec<V>`	Value slots parallel to `keys`. Prefer `values()`.
`live`	`Vec<int>`	`1` where the slot holds an entry, `0` where it was removed.

Associated functions#

Name	Description
`with_capacity`	Creates an empty map with room for about `cap` buckets before it grows.
`new`	Creates an empty map.

Methods#

Name	Description
`size`	Returns the number of entries.
`is_empty`	Returns `true` when the map has no entries.
`capacity`	Returns the number of buckets.
`clear`	Removes every entry, keeping the bucket count.
`keys`	Returns the keys, in insertion order.
`values`	Returns the values, in the insertion order of their keys.
`iter`	Returns an iterator over the entries, in insertion order.
`insert`	Stores `v` under `k`, replacing any value already there.
`contains`	Returns `true` when the map has an entry for `k`.
`get_or`	Returns the value stored under `k`, or `fallback` when there is none.
`get`	Returns the value stored under `k`, or `None` when there is none.
`remove`	Removes the entry for `k`.

Trait implementations#

IntoIterator for HashMap<K, V>

Invariants#

Checked according to --contracts (see Contracts).

invariant self.len >= 0 && self.len <= self.keys.len()
invariant self.cap >= 8 && self.heads.len() == self.cap
invariant self.vals.len() == self.keys.len() && self.next.len() == self.keys.len()
invariant self.live.len() == self.keys.len()

Examples#

use collections::map::{HashMap};
use tests::assert;
let ages: HashMap<string, int> = HashMap::new();
ages.insert("ada", 36);
ages.insert("alan", 41);
ages.insert("ada", 37);
assert!(ages.size() == 2);
assert!(ages.get_or("ada", 0) == 37);
assert!(ages.get_or("grace", -1) == -1);

let total = 0;
for e in ages {
    total = total + e.value;
}
assert!(total == 78);