import type { Constraint } from "./constraint.js";
export type Schema<T> = {
    readonly marshal: (value: T) => string;
    readonly unmarshal: (value: string) => T;
    readonly constraints: Constraint<T>[];
    readonly accept: <U>(visitor: Visitor<U>) => U;
};
export type MarshalFn<T> = Schema<T>["marshal"];
export type UnmarshalFn<T> = Schema<T>["unmarshal"];
export type ScalarSchema<T> = Schema<T> & {
    readonly description: string;
};
export type EnumSchema<T> = Schema<T> & {
    readonly members: Record<string, T>;
};
export type URLSchema = Schema<URL> & {
    readonly base: URL | undefined;
    readonly protocols: string[] | undefined;
};
export declare function createString(description: string, constraints: Constraint<string>[]): ScalarSchema<string>;
export declare function createEnum<T>(members: Record<string, T>, marshal: MarshalFn<T>, unmarshal: UnmarshalFn<T>, constraints: Constraint<T>[]): EnumSchema<T>;
export declare function createURL(base: URL | undefined, protocols: string[] | undefined, marshal: MarshalFn<URL>, unmarshal: UnmarshalFn<URL>, constraints: Constraint<URL>[]): URLSchema;
export declare function createScalar<T>(description: string, marshal: MarshalFn<T>, unmarshal: UnmarshalFn<T>, constraints: Constraint<T>[]): ScalarSchema<T>;
export type Visitor<T> = {
    readonly visitEnum: (e: EnumSchema<any>) => T;
    readonly visitScalar: (s: ScalarSchema<any>) => T;
    readonly visitURL: (s: URLSchema) => T;
};
export declare class InvalidEnumError<T> extends Error {
    constructor(members: Record<string, T>);
}
type Stringable = {
    readonly toString: () => string;
};
export declare function toString<T extends Stringable>(v: T): string;
export {};