/** What every function in `agency-lang/local` that can fail returns: the
 *  value, or a message saying why there is none.
 *
 *  ```ts
 *  const tags = await tagImage({ model: "wd14-tagger", image: "page.png" });
 *  if (tags.success) {
 *    console.log(tags.value);
 *  } else {
 *    console.error(tags.error);
 *  }
 *  ``` */
export type Result<T> = {
    success: true;
    value: T;
} | {
    success: false;
    error: string;
};
export declare function success<T>(value: T): Result<T>;
export declare function failure<T = never>(error: string): Result<T>;