import { Monad, Unit } from './monad';
export interface MaybeMonad<A> extends Monad<A> {
    map<B>(f: (a: A) => B): MaybeMonad<B>;
}
export declare const MaybeUnit: Unit<MaybeMonad<any>, any>;
export declare namespace MaybeMonad {
    function fromNullable<A>(value: A | null): MaybeMonad<A>;
}