not

import { not } from 'patronum';
// or
import { not } from 'patronum/not';

Motivation

The method allows to apply boolean NOT to a value. Actually converts any “falsey” value into true (null, 0, empty string). But undefined is not present, because Store cannot hold it inside.

Formulae

$result = not($value);

$result store contains false if $value contains any “truthy” value, otherwise there will be true

Arguments

$value: Store<T> — Any value, that required to be “inverted”

Returns

$result: Store<boolean>

Example

const $isFinished = createStore(false);
const $stillGoingOn = not($isFinished);

console.assert(true === $stillGoingOn.getState());

Try it

Alternative

const $isFinished = createStore(false);
const $stillGoingOn = $isFinished.map((isFinished) => !isFinished);

console.assert(true === $stillGoingOn.getState());