variable / @typed/fx

RefOption.contains

Check if the current state of a RefOption contains a value.

Package version
2.0.0-beta.13
Category
State predicates
Since
1.18.0
Member of
RefOption

Import

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

Access RefOption.contains through the imported RefOption 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 contains: {
    <A>(value: A): <E, R>(ref: RefOption<A, E, R>) => RefSubject.Computed<boolean, E, R>;
    <A, E, R>(ref: RefOption<A, E, R>, value: A): RefSubject.Computed<boolean, E, R>;
};

Why

Makes contains a live projection of the option; consumers can sample it now or observe it without copying the source state.

Ownership and lifetime

The contains 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