import type { Fn2, NumOrString } from "@thi.ng/api";
import type { ISubscribable } from "@thi.ng/rstream";
import type { IComponent, IMountWithState, ListBaseOpts, NumOrNode } from "./api.js";
import { Component } from "./component.js";
export interface KListOpts<T> extends ListBaseOpts<T> {
    key?: Fn2<T, number, NumOrString>;
}
export interface KListItem {
    k: NumOrString;
    v: IComponent;
}
/**
 * Similar to {@link $list}, however additionally uses keying to establish list
 * item identities and uses these keys (and *only* these!) in a more complex
 * diffing algorithm to avoid re-initialization of list items if they've been
 * re-ordered or changed positions due to removal/insertion of other items in
 * the list.
 *
 * @remarks
 * The given `key` function is used to obtain a *unique* key value for each list
 * item obtained from the reactive arrays obtained from `src`. Like a hash, the
 * key value MUST represent an item's *current* value such that if the value
 * changes, so does the key.
 *
 * See {@link ListBaseOpts} for more details about wrapped vs. bare lists, i.e.
 * using a list wrapper element for items or attaching list items directly to
 * this component's parent. Also see this example project to illustrate the
 * structure/possibilities of bare lists:
 *
 * - https://demo.thi.ng/umbrella/rdom-bare-lists/
 *
 * @example
 * ```ts
 * import { $klist } from "@thi.ng/rdom";
 * import { reactive } from "@thi.ng/rstream";
 *
 * const items = reactive([{id: "a", val: 1}, {id: "b", val: 2}, {id: "c", val: 3}]);
 *
 * $klist(
 *   // data source (any rstream subscribable)
 *   items,
 *   {
 *     // outer list element & attribs
 *     el: "ul",
 *     attribs: { class: "list red" },
 *     // list item component constructor
 *     item: (x) => ["li", {}, x.id, ` (${x.val})`],
 *     // key function
 *     key: (x) => `${x.id}-${x.val}`
 *   }
 * ).mount(document.body);
 *
 * // update list:
 * // - item a will be removed
 * // - item b is unchanged
 * // - item d will be newly inserted
 * // - item c will be updated (due to new value)
 * setTimeout(
 *   () => {
 *     items.next([
 *       { id: "b", val: 2 },
 *       { id: "d", val: 4 },
 *       { id: "c", val: 30 },
 *     ]);
 *   },
 *   1000
 * );
 * ```
 *
 * @param src -
 * @param opts -
 */
export declare const $klist: <T>(src: ISubscribable<T[]>, opts: KListOpts<T>) => IComponent<T[]>;
export declare class KList<T> extends Component<T[]> implements IMountWithState<T[]> {
    protected opts: KListOpts<T>;
    protected items?: KListItem[];
    protected cache?: Map<NumOrString, KListItem>;
    protected anchor?: Comment;
    constructor(opts: KListOpts<T>);
    mount(parent: ParentNode, index: NumOrNode, state: T[]): Promise<Element>;
    unmount(): Promise<void>;
    update(curr: T[]): Promise<void>;
}
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