type KeyType = string | number | Date;
export interface BTreeOptions {
    order?: number;
    unique?: boolean;
    keyParser?: (key: KeyType) => KeyType;
}
export declare class BTreeIndex {
    private root;
    private readonly order;
    private readonly unique;
    private readonly keyParser;
    /**
     * Creates a new B-tree index instance
     * @param options - Configuration options for the B-tree
     * @param options.order - The order (degree) of the B-tree. Default is 3
     * @param options.unique - Whether duplicate keys are allowed. Default is false
     * @param options.keyParser - Custom function to parse/transform keys. Default uses internal parser
     */
    constructor(options?: BTreeOptions);
    private defaultKeyParser;
    private createNode;
    private compare;
    insert(key: KeyType, docId: string): void;
    private splitChild;
    private insertNonFull;
    delete(key: KeyType, docId: string): void;
    private deleteRecursive;
    private deleteInternalNode;
    private rebalance;
    search(key: KeyType): string[];
    private searchRecursive;
    searchRange(min: number, max: number): string[];
    private searchRangeRecursive;
    compact(): void;
    private compactRecursive;
}
export {};