import { type ImmutableArray } from "../util/array.js";
import type { SchemaOptions } from "./Schema.js";
import { Schema } from "./Schema.js";
/**
 * Set of options for a `ChoiceSchema` can be either:
 * - Dictionary of string options in `{ key: title }` format.
 */
export type ChoiceOptions<K extends string> = {
    readonly [KK in K]: string;
};
/**
 * Things that can be converted to a choice options dictionary.
 * - Array of string options in `[key]` format (`key` will be used as the `title` too).
 */
export type PossibleChoiceOptions<K extends string> = ImmutableArray<K> | ChoiceOptions<K>;
/** Allowed options for `ChoiceSchema` */
export interface ChoiceSchemaOptions<K extends string> extends Omit<SchemaOptions, "value"> {
    /** Specify correct options using a dictionary of entries. */
    readonly options: PossibleChoiceOptions<K>;
    /** Default option for the value. */
    readonly value?: K;
}
/** Choose from an allowed set of values. */
export declare class ChoiceSchema<K extends string> extends Schema<K> {
    readonly value: K | undefined;
    readonly options: ChoiceOptions<K>;
    constructor({ one, title, placeholder, options, value, ...rest }: ChoiceSchemaOptions<K>);
    validate(unsafeValue?: unknown): K;
    format(value: K): string;
}
/** Choose from an allowed set of values. */
export declare function CHOICE<K extends string>(options: PossibleChoiceOptions<K>): ChoiceSchema<K>;