import { Relation, ThroughRelation } from "./types.js";
import { PrefixIndexDepth } from "./utils/typs.js";
/** Default prefix for index directories. */
export declare const INDEX_PREFIX = "index";
/** Default prefix index depth. */
export declare const DEFAULT_INDEX_DEPTH: PrefixIndexDepth;
/**
 * Returns the path to the prefixes index dir.
 */
export declare function getIndexDir(sourceName: string, field: string): string;
/**
 * Get Prefix Index directories path converted with Unicode.
 */
export declare function getPrefixIndexPath(value: string, depth: number): string;
/**
 * Determines whether the relation is a through-type.
 */
export declare function isThroughRelation(rel: Relation): rel is ThroughRelation;
/**
 * Sort PrefixIndexLine comparator factory.
 */
export declare function indexSort<T>(keys?: (keyof T)[]): (a: T, b: T) => number;