import { BaseElement } from "../element.js";
export declare function attributes<A extends Attributes.Spec>(element: BaseElement, spec: A): Attributes.SoftenSpec<A>;
export declare namespace Attributes {
    type HardValue = (typeof String | typeof Number | typeof Boolean);
    type SoftenValue<H extends HardValue> = (H extends typeof String ? string | undefined : H extends typeof Number ? number | undefined : H extends typeof Boolean ? boolean : never);
    export type Spec = {
        [key: string]: HardValue;
    };
    export type SoftenSpec<A extends Spec> = {
        [P in keyof A]: SoftenValue<A[P]>;
    };
    export const proxy: <A extends Spec>(element: HTMLElement, spec: A) => SoftenSpec<A>;
    export function on_change(element: HTMLElement, handle_change: () => void): () => void;
    export {};
}