declare module 'svelte/store' {
    export type Subscriber<T> = (value: T) => void
    export type Unsubscriber = () => void

    export interface Readable<T> {
        subscribe(run: Subscriber<T>): Unsubscriber
    }

    export function readable<T>(
        value: T,
        start?: (set: Subscriber<T>) => Unsubscriber | void,
    ): Readable<T>
}