variable / @typed/fx

RefRecord.mapKeys

Map keys to different keys.

Package version
2.0.0-beta.7
Category
Derived queries
Since
1.18.0
Member of
RefRecord

Import

import { RefRecord } from "@typed/fx";

Access RefRecord.mapKeys through the imported RefRecord export. Its declaration below describes the member.

This public exposure is a re-export. Its import path is supported; declaration documentation is shared with the other public exposures below.

Signatures

export declare const mapKeys: {
    <K extends string, K2 extends string>(f: (key: K) => K2): <V, E, R>(ref: RefRecord<K, V, E, R>) => RefSubject.Computed<Record.ReadonlyRecord<K2, V>, E, R>;
    <K extends string, V, E, R, K2 extends string>(ref: RefRecord<K, V, E, R>, f: (key: K) => K2): RefSubject.Computed<Record.ReadonlyRecord<K2, V>, E, R>;
};

Why

Projects record state with map keys for both current reads and future pushes, avoiding a second mutable cache of the derived value.

Ownership and lifetime

The map keys view retains no independent state. An Effect read samples the source once; Fx observation follows later pushes and its observing Scope owns subscription cleanup.

Other public imports

These import paths expose the same declaration. Each page retains its own public name and signature.

Source