import { Failure, Branch, Path } from './struct-error';
import { Superstruct } from './superstruct';
/**
 * A symbol to set on `Struct` objects to test them against later.
 */
export declare const STRUCT: unique symbol;
/**
 * Check if a value is a `Struct` object.
 */
export declare const isStruct: (value: any) => value is Struct;
/**
 * This abstract `Struct` factory creates a generic struct that validates values
 * against a `Validator` function.
 */
export declare const createStruct: (props: {
    kind: string;
    type: string;
    defaults: () => any;
    struct: Superstruct;
}) => Struct;
/**
 * `Struct` validators encapsulate the validation logic for a specific type of
 * data (either custom or built-in). They have a set of methods that allow you
 * to validate input in various ways, while producing detailed errors.
 *
 * They are created by the [[Superstruct]] factory functions. You can call them
 * directly for the simple case, or use one of their validation methods.
 *
 * ```js
 * const Struct = struct({
 *   id: 'number',
 *   name: 'string',
 * })
 *
 * const result = Struct(data) // Throws if invalid!
 *
 * const [error, result] = Struct.validate(data)
 *
 * if (Struct.test(data)) {
 *    // ...
 * }
 * ```
 */
export interface Struct {
    /**
     * All structs are functions that are shorthand for calling [[Struct.assert]].
     */
    (value: any): any;
    /**
     * The struct's name.
     *
     * ```js
     * 'object'
     * 'union'
     * 'email'
     * ```
     */
    kind: string;
    /**
     * A string representing the type of the struct. These strings are purely for
     * user-facing error messages, and aren't canonical. They are similar to the
     * syntax that TypeScript uses.
     *
     * ```js
     * '{id,name,email}'
     * 'string | number'
     * 'email'
     * ```
     */
    type: string;
    /**
     * Get the default value for a struct.
     *
     * ```js
     * const defaults = Struct.default()
     * ```
     */
    default(): any;
    /**
     * Run the low-level validation function a struct, returning a tuple that
     * contains either a list of [[Failure]] objects, or a resulting value.
     *
     * This method is fairly low-level and not for normal use.
     *
     * ```js
     * const [failures, result] = Struct.check(value, branch, path)
     * ```
     */
    check(value: any, branch: Branch, path: Path): [Failure[]?, any?];
    /**
     * Validate a `value`, returning the resulting value, and throwing an error if
     * validation fails.
     *
     * ```js
     * try {
     *   const result = Struct.assert(value)
     *   // ...
     * } catch (e) {
     *   // ...
     * }
     * ```
     */
    assert(value: any): any;
    /**
     * Validate a `value`, returning a boolean indicating whether it's valid.
     *
     * Note: Using this method does not give you access to the defaults that may
     * be associated with a struct, so it doesn't guarantee that the value you
     * have passes, just that the value with defaults passes.
     *
     * ```js
     * if (Struct.test(value)) {
     *   // ...
     * }
     * ```
     */
    test(value: any): boolean;
    /**
     * Validate a `value` returning a tuple containing an error if the validation
     * fails, or the resulting value if it succeeds.
     *
     * ```js
     * const [error, result] = Struct.validate(value)
     * ```
     */
    validate(value: any): [Error?, any?];
    /**
     * Create a low-level [[Failure]] object for the struct.
     *
     * ```js
     * const failure = Struct.fail({ value, branch, path })
     * ```
     */
    fail(obj: {
        value: any;
        branch: Branch;
        path: Path;
        type?: string;
    }): Failure;
}