Struct Encoder

pub struct Encoder<K: Hash, V> {
    values: Vec<(K, V)>,
    codes: AHashMap<K, u32>,
}

This structure represents an encoder that maps unique keys to integer codes while storing associated values. It encapsulates a vector of key-value pairs alongside a hash map that records the corresponding code for each key.

The interface supports operations to insert new key-value associations, retrieve a code given a key, and decode keys and values based on their assigned codes, ensuring efficient bidirectional lookup between keys and integer representations.

Fields

values: Vec<(K, V)>

codes: AHashMap<K, u32>

Implementations

impl<K: Hash + Clone + Eq, V> Encoder<K, V>

pub fn new() -> Self

Creates a new encoder instance with no stored key-value pairs.

This constructor initializes the internal storage to be empty, allowing subsequent insertions to assign unique numerical codes to keys while associating corresponding values.

pub fn insert(&mut self, k: K, v: V) -> u32

Inserts a new key-value pair into the encoder, assigning and returning a unique numeric code for the key.

Generates a code based on the current state of internal storage, clones the key, and stores the pair in parallel structures that maintain both an ordered list of values and a mapping from keys to their corresponding codes, enabling efficient retrieval and translation between keys and their numeric identifiers.

pub fn encode(&self, t: &K) -> Option<u32>

Retrieves a numeric code corresponding to a given key from the internal mapping.

Returns an optional value representing the unique encoding if the key exists, or None otherwise.

pub fn decode(&self, t: u32) -> &K

Retrieves a reference to the key corresponding to the provided encoded numeric value.

Returns the key by interpreting the given integer as an index into an internal collection, enabling reverse mapping from a numeric code back to its associated key.

pub fn value(&self, t: u32) -> &V

Returns a reference to the value associated with the supplied numerical code from the internal storage. This method converts the provided u32 code into an index and accesses the corresponding entry, retrieving the second element of the stored key–value pair.

Trait Implementations

impl<K: Hash + Clone + Eq, V> Default for Encoder<K, V>

fn default() -> Self

Returns a new instance with default settings by invoking the standard constructor. This method provides the default initialization behavior by delegating its work to the dedicated creation function, ensuring consistent instantiation for the type.