import { Property } from "./Property";
export declare type Lens<S, A> = ObjectSetLens<S, A> | ObjectUpdateLens<S, A> | VanLaarhovenLens<S, A>;
export interface SetOp {
    <T>(atom: Atom<T>, value: T): void;
    <T>(atom: Atom<T>): (value: T) => void;
}
export interface ModifyOp {
    <T>(atom: Atom<T>, f: (state: T) => T): void;
    <T>(atom: Atom<T>): (f: (state: T) => T) => void;
}
export interface ViewOp {
    <S extends object, Prop extends keyof (S)>(atom: Atom<S>, prop: Prop): Atom<S[Prop]>;
    <S extends object, Prop extends keyof (S)>(atom: Atom<S>): (prop: Prop) => Atom<S[Prop]>;
    <S, A>(atom: Atom<S>, lens: Lens<S, A>): Atom<A>;
    <S, A>(atom: Atom<S>): (lens: Lens<S, A>) => Atom<A>;
}
export declare function atom<T>(initialValue: T): Atom<T>;
export declare const get: typeof _get;
export declare const set: SetOp;
export declare const modify: ModifyOp;
export declare const view: ViewOp;
export declare abstract class Atom<T> extends Property<T> {
}
declare function _get<T>(a: Atom<T>): T;
interface Functor<A> {
    fmap<B>(fn: (a: A) => B): Functor<B>;
}
interface ObjectSetLens<S, A> {
    get(s: S): A;
    set(a: A, s: S): S;
}
interface ObjectUpdateLens<S, A> {
    get(s: S): A;
    update(s: S, f: (a: A) => A): S;
}
declare type VanLaarhovenLens<S, A> = (a2f: (a: A) => Functor<A>) => (s: S) => Functor<S>;
export {};