declare const modelFlowSymbol: unique symbol;
/**
 * Returns if the given function is a model flow or not.
 *
 * @param fn Function to check.
 * @returns
 */
export declare function isModelFlow(fn: unknown): fn is Function & Record<typeof modelFlowSymbol, unknown>;
/**
 * Decorator that turns a function generator into a model flow.
 */
export declare function modelFlow(...args: any[]): void;
/**
 * Tricks the TS compiler into thinking that a model flow generator function can be awaited
 * (is a promise).
 *
 * @template A Function arguments.
 * @template R Return value.
 * @param fn Flow function.
 * @returns
 */
export declare function _async<A extends any[], R>(fn: (...args: A) => Generator<any, R, any>): (...args: A) => Promise<R>;
/**
 * Makes a promise a flow, so it can be awaited with yield*.
 *
 * @template T Promise return type.
 * @param promise Promise.
 * @returns
 */
export declare function _await<T>(promise: Promise<T>): Generator<Promise<T>, T, unknown>;
export {};