import { Either } from "fp-ts/Either";
import { DecodeError } from "./error.js";
export declare const decode: <T, R extends Request | Response>(fn: (request: R) => Promise<T>) => (arg: R) => Promise<Either<DecodeError, Awaited<T>>>;
/**
 * copied from
 * https://github.com/Effect-TS/effect/blob/46a575f48a05457b782fb21f7827d338c9b59320/packages/effect/src/Function.ts#L30
 *
 * Creates a function that can be used in a data-last (aka `pipe`able) or
 * data-first style.
 *
 * The first parameter to `dual` is either the arity of the uncurried function
 * or a predicate that determines if the function is being used in a data-first
 * or data-last style.
 *
 * Using the arity is the most common use case, but there are some cases where
 * you may want to use a predicate. For example, if you have a function that
 * takes an optional argument, you can use a predicate to determine if the
 * function is being used in a data-first or data-last style.
 *
 * @param arity - Either the arity of the uncurried function or a predicate
 *                which determines if the function is being used in a data-first
 *                or data-last style.
 * @param body - The definition of the uncurried function.
 *
 * @example
 * import { dual, pipe } from "effect/Function"
 *
 * // Exampe using arity to determine data-first or data-last style
 * const sum: {
 *   (that: number): (self: number) => number
 *   (self: number, that: number): number
 * } = dual(2, (self: number, that: number): number => self + that)
 *
 * assert.deepStrictEqual(sum(2, 3), 5)
 * assert.deepStrictEqual(pipe(2, sum(3)), 5)
 *
 * // Example using a predicate to determine data-first or data-last style
 * const sum2: {
 *   (that: number): (self: number) => number
 *   (self: number, that: number): number
 * } = dual((args) => args.length === 1, (self: number, that: number): number => self + that)
 *
 * assert.deepStrictEqual(sum(2, 3), 5)
 * assert.deepStrictEqual(pipe(2, sum(3)), 5)
 *
 * @since 2.0.0
 */
export declare const dual: {
    <DataLast extends (...args: Array<any>) => any, DataFirst extends (...args: Array<any>) => any>(arity: Parameters<DataFirst>["length"], body: DataFirst): DataLast & DataFirst;
    <DataLast extends (...args: Array<any>) => any, DataFirst extends (...args: Array<any>) => any>(isDataFirst: (args: IArguments) => boolean, body: DataFirst): DataLast & DataFirst;
};