sharkey/packages/backend/src/misc/prelude/maybe.ts
Shun Sakai c2370a1be6
chore: 著作権とライセンスについての情報を各ファイルに追加する (#11348)
* chore: Add the SPDX information to each file

Add copyright and licensing information as defined in version 3.0 of
the REUSE Specification.

* tweak format

---------

Co-authored-by: syuilo <Syuilotan@yahoo.co.jp>
2023-07-27 14:31:52 +09:00

26 lines
422 B
TypeScript

/*
* SPDX-FileCopyrightText: syuilo and other misskey contributors
* SPDX-License-Identifier: AGPL-3.0-only
*/
export interface IMaybe<T> {
isJust(): this is IJust<T>;
}
export interface IJust<T> extends IMaybe<T> {
get(): T;
}
export function just<T>(value: T): IJust<T> {
return {
isJust: () => true,
get: () => value,
};
}
export function nothing<T>(): IMaybe<T> {
return {
isJust: () => false,
};
}