sharkey/packages/backend/src/misc/prelude/maybe.ts

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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,
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get: () => value,
};
}
export function nothing<T>(): IMaybe<T> {
return {
isJust: () => false,
};
}