/**
 * Filters for extracting query strings
 * @packageDocumentation
 */
import { Filter } from "../filter";
import { IsInstanceOf } from "../types";
/**
 * Schema for query string validation and extraction
 */
export declare type QuerySchema = {
    [key: string]: typeof String | typeof Number | typeof Boolean | {
        optional: true;
        type: typeof String | typeof Number;
    };
};
/**
 * Converts a [[`QuerySchema`]] to the type it represents
 */
declare type QueryMap<S extends QuerySchema> = {
    [K in keyof S]: true extends IsInstanceOf<S[K], string> ? string : true extends IsInstanceOf<S[K], number> ? number : true extends IsInstanceOf<S[K], boolean> ? boolean : S[K] extends {
        optional: true;
        type: infer T;
    } ? true extends IsInstanceOf<T, string> ? string | undefined : true extends IsInstanceOf<T, number> ? number | undefined : never : never;
};
/**
 * Validates and extracts the query string following the provided schema
 *
 * ```ts
 * // Will match ?limit=50&strip
 * // Generic type annotation not required, only present for clarity's sake
 * const query: Filter<[
 *     { limit: number; skip?: number; strip: boolean }
 * ]> = query({
 *     limit: Number,
 *     skip: { optional: true, type: Number },
 *     strip: Boolean,
 * });
 * ```
 *
 * @param schema - Schema
 * @param extra - Whether to include extra fields not diescribed in the schema in the extracted object
 */
export declare function query<T extends QuerySchema>(schema: T, extra?: boolean): Filter<[QueryMap<T>]>;
/**
 * Extracts the query string
 */
export declare const any: Filter<[URLSearchParams]>;
/**
 * Extracts the raw query string
 */
export declare const raw: Filter<[string]>;
export {};