gistfile1.txt

export type Response<T, E> = Ok<T, E> | Err<T, E>;

class Ok<T, E> {
  readonly value: T;

  constructor(value: T) {
    this.value = value;
  }

  isOk(): this is Ok<T, E> {
    return true;
  }

  isErr(): this is Err<T, E> {
    return false;
  }
}

class Err<T, E> {
  readonly value: E;

  constructor(value: E) {
    this.value = value;
  }

  isOk(): this is Ok<T, E> {
    return false;
  }

  isErr(): this is Err<T, E> {
    return true;
  }
}

export const Result = {
  ok: <T, E>(value: T): Ok<T, E> => new Ok(value),
  err: <T, E>(error: E): Err<T, E> => new Err(error),
};