Struct datazoo::index_multimap::IndexMultimap

pub struct IndexMultimap<K: Index, V: From<usize>> { /* private fields */ }

A multimap that goes from an integer to multiple integers.

This is a 1-to-N mapping, see PackedIntArray for 1-to-(1|0) mapping. JaggedBitset is an alternative in case you expect the largest row to be way larger than the smaller ones.

It is not recommended to use this data structure if you expect to have large values in your key/value space. Or a single very long row and most other rows empty or wtih very low values.

This data structure might be a good solution if you have an index to a small array or an incrementing counter.

Design

This is basically a wrapper around BitMatrix, where K is the row index and V are indices in the row bitset.

Example

use datazoo::IndexMultimap;

let multimap: IndexMultimap<usize, usize> = [
    (0, 1), (0, 5), (0, 2), (0, 2),
    (1, 7), (1, 0), (1, 1),
    (2, 32), (2, 0), (2, 12), (2, 2), (2, 11), (2, 10), (2, 13), (2, 4),
    (4, 1)
].into_iter().collect();
let rows: [&[usize]; 5] = [
    &[1, 2, 5],
    &[0, 1, 7],
    &[0, 2, 4, 10, 11, 12, 13, 32],
    &[],
    &[1],
];
for (i, row) in rows.iter().enumerate() {
    let multimap_row: Box<[usize]> = multimap.get(&i).collect();
    assert_eq!(*row, &*multimap_row, "{i}");
}

Implementations

impl<K: Index, V: From<usize>> IndexMultimap<K, V>

pub fn get<'a>(&'a self, key: &K) -> impl Iterator<Item = V> + 'a

Get the values associated with given K

Trait Implementations

impl<K: Clone + Index, V: Clone + From<usize>> Clone for IndexMultimap<K, V>

fn clone(&self) -> IndexMultimap<K, V>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<K: Debug + Index, V: Debug + From<usize>> Debug for IndexMultimap<K, V>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<K: Index, V: From<usize> + Index> FromIterator<(K, V)> for IndexMultimap<K, V>

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

Create a IndexMultimap with all associations.

Note that K and V will be dropped.