declare enum EitherTag {
    Left = "left",
    Right = "right"
}
export declare type Left<T> = [tag: EitherTag.Left, value: T];
export declare type Right<T> = [tag: EitherTag.Right, value: T];
export declare type Either<L, R> = Left<L> | Right<R>;
declare function isLeft<L>(either: Either<L, unknown>): either is Left<L>;
declare function assertLeft<L>(either: Either<L, unknown>, message?: string): asserts either is Left<L>;
declare function isRight<R>(either: Either<unknown, R>): either is Right<R>;
declare function assertRight<R>(either: Either<unknown, R>, message?: string): asserts either is Right<R>;
export declare type Match<L, R, IfLeft, IfRight> = {
    readonly left: (value: L) => IfLeft;
    readonly right: (value: R) => IfRight;
};
export declare const Either: {
    is: {
        left: typeof isLeft;
        right: typeof isRight;
    };
    to: {
        leftValue: <L>(either: Left<L>) => L;
        rightValue: <R>(either: Right<R>) => R;
    };
    assert: {
        left: typeof assertLeft;
        right: typeof assertRight;
    };
    of: {
        left: <L_1>(value: L_1) => Left<L_1>;
        right: <R_1>(value: R_1) => Right<R_1>;
    };
    match: <L_2, R_2, IfLeft, IfRight>(either: Either<L_2, R_2>, match: Match<L_2, R_2, IfLeft, IfRight>) => IfLeft | IfRight;
};
export {};