import * as React from "react";
export interface Action<a> extends Fun<a, a> {
}
export interface Unit {
}
export declare type Fun<a, b> = (_: a) => b;
export declare let then: <a, b, c>(f: Fun<a, b>, g: Fun<b, c>) => Fun<a, c>;
export interface Pair<a, b> {
    fst: a;
    snd: b;
}
export declare let mk_pair: <a, b>(a: a, b: b) => {
    fst: a;
    snd: b;
};
export interface Sum<a, b> {
    v: {
        kind: "l";
        v: a;
    } | {
        kind: "r";
        v: b;
    };
}
export declare let inl: <a, b>(a: a) => Sum<a, b>;
export declare let inr: <a, b>(b: b) => Sum<a, b>;
export interface Option<a> extends Sum<Unit, a> {
}
export declare let none: <a>() => Option<a>;
export declare let some: <a>(v: a) => Option<a>;
export interface Options {
    readonly?: boolean;
    autofocus?: boolean;
    key?: string;
    className?: string;
    role?: string;
    style?: React.CSSProperties;
    id?: string;
    extraProperties?: {};
}
export declare let option: <t, k extends keyof t>(k: k, o?: t | undefined) => t[k] | undefined;
export interface WidgetBase<o> {
    run: (on_done: (output: o) => void) => JSX.Element;
}
export interface Widget<o> extends WidgetBase<o> {
    map: <o2>(f: Fun<o, o2>) => Widget<o2>;
    filter: (p: Fun<o, boolean>) => Widget<o>;
    then: <o2>(k: Fun<o, Widget<o2>>) => Widget<o2>;
    never: <o2>() => Widget<o2>;
}
export declare let mk_widget: <w extends WidgetBase<o>, o>(w: w) => Widget<o>;
export declare type IOWidget<i, o> = (input: i) => Widget<o>;
export declare const nothing: <o>() => Widget<o>;
export declare let never_io: <i, o1, o2>(inner_widget: IOWidget<i, o1>) => IOWidget<i, o2>;
export declare let never: <o>(inner_widget: Widget<{}>) => Widget<o>;
export declare let map: <a, b>(f: Fun<a, b>) => Fun<Widget<a>, Widget<b>>;
export interface JoinerProps<a> {
    widget_a2: Widget<Widget<a>>;
    on_done_a: (output_a: a) => void;
}
export interface JoinerState<a> {
    inner_widget: Widget<a> | undefined;
}
export declare class Joiner<a> extends React.Component<JoinerProps<a>, JoinerState<a>> {
    constructor(props: JoinerProps<a>, context: any);
    render(): JSX.Element;
}
export declare let join: <a>(widget_a2: Widget<Widget<a>>) => Widget<a>;
export declare let bind: <a, b>(widget_a: Widget<a>, widget_b_from_a: Fun<a, Widget<b>>) => Widget<b>;
export declare let filter: <a>(p: Fun<a, boolean>) => Fun<Widget<a>, Widget<a>>;