UNPKG

@rimbu/proximity

Version:

Immutable ProximityMap implementation for TypeScript

35 lines (34 loc) 1.57 kB
import type { Distance, DistanceFunction } from './distanceFunction.mjs'; /** * Match between a reference key and the closest key in a [key, value] collection: * * * `key` is the key closest to the reference key * * * `value` is the value associated with the closest key * * * `distance` is the distance between the closest key and the reference key; * it is always a finite value */ export type NearestKeyMatch<K, V> = Readonly<{ key: K; value: V; distance: Distance; }>; /** * Given an Iterable of [key, value] entries, applies the distance function to * each key, finding the one closest to the input key, also returning its * associated value as well as the related distance; returns `undefined` * only when there are no successful match - that is, all the keys have +inf distance. * * Performs a full linear scan unless a distance equal to 0 is encountered, in which * case the function returns immediately; otherwise, the algorithm selects the * smallest *non-infinite* distance: if multiple keys happen to have such distance, * the selection order is not guaranteed. * * @param distanceFunction Returns the distance between two keys * @param key The key used as a reference to find the closest key * @param entries The [key, value] entries * @returns A `NearestKeyMatch` object if a closest key - * having a *finite distance* - exists; `undefined` otherwise */ export declare function findNearestKeyMatch<K, V>(distanceFunction: DistanceFunction<K>, key: K, entries: Iterable<readonly [K, V]>): NearestKeyMatch<K, V> | undefined;