import type { BKTreeNode, DistanceFunction, IBKTree } from './types';
export declare class BKTree implements IBKTree {
    private root;
    private getDistance;
    constructor({ getDistance, root, }?: {
        getDistance?: DistanceFunction;
        root?: BKTreeNode;
    });
    /**
     * Insert a word into the tree.
     *
     * @param word - The word to insert.
     */
    insert(word: string): void;
    /**
     * Find all words in the tree that are within a given edit distance of the query.
     *
     * @param query - The query to find words for.
     * @param options - The options to use for the find operation.
     * @param options.maxError - The maximum edit distance.
     * @param options.limit - The maximum number of results to return.
     * @returns An array of words that are within the given edit distance of the query.
     */
    find(query: string, options?: {
        maxError?: number;
        limit?: number;
    }): string[];
    /**
     * Lookup the closest word to the query.
     *
     * @param query - The query to lookup.
     * @returns The closest word to the query, or `null` if the tree is empty.
     */
    lookup(query: string): string | null;
    /**
     * Serialize the tree to a JSON string.
     *
     * @returns The serialized tree.
     */
    toJSON(): string;
    static fromJSON(jsonStr: string): BKTree;
}