import { NodeDefinition, StatelessGraphNode, StatelessNodeDefinition, StatelessNodeType } from '../../types/graph';
import { ContextNodeDefinition } from './context';
/**
 * An instance of the [fn](../modules/_nodes_graph_fn_.html#fn) node.
 * See the [fn](../modules/_nodes_graph_fn_.html#fn) documentation to find out more.
 */
export interface FnNode extends StatelessGraphNode<'fn', FnNodeProperties> {
}
/**
 * A definition of the [fn](../modules/_nodes_graph_fn_.html#fn) node.
 * See the [fn](../modules/_nodes_graph_fn_.html#fn) documentation to learn more.
 */
export interface FnNodeDefinition extends StatelessNodeDefinition<'fn', FnNodeProperties> {
}
export interface FnNodeProperties {
    argIds: Array<string>;
    body: NodeDefinition;
    hasNamedArgs: boolean;
}
/**
 * The implementation of the [fn](../modules/_nodes_graph_fn_.html#fn).
 * See the [fn](../modules/_nodes_graph_fn_.html#fn) documentation to learn more.
 */
export declare const FnNodeType: StatelessNodeType<'fn', FnNodeProperties>;
export declare type NamedFnArgs = {
    [argName: string]: ContextNodeDefinition;
};
/**
 * Creates a new instance of a [[fn]] node, which is a type of a [[NodeDefinition]] used for representing executable
 * functions implemented with muster [[NodeDefinition]]s. These functions are safely serializable and can be executed
 * on a remote muster instances.
 *
 * The [[fn]] is being used by the collection transforms to represent filters and other types of collection transforms.
 *
 * The [[fn]] can be executed with the help of [[call]] and [[apply]].
 *
 *
 * @example **Create a simple [[fn]]**
 * ```js
 * import { fn, value } from '@dws/muster';
 *
 * fn(() => value(true));
 * ```
 * This example shows how to create a very basic [[fn]] that simply returns a true [[value]]
 * ever time it gets called.
 *
 *
 * @example **Create an [[fn]] with args**
 * ```js
 * import { add, fn } from '@dws/muster';
 *
 * fn((num) => add(num, 5));
 * ```
 * This example shows how to create an [[fn]] capable of adding 5 to an argument.
 *
 *
 * @example **Calling an [[fn]]**
 * ```js
 * import muster, { add, call, fn } from '@dws/muster';
 *
 * const app = muster({
 *   addFive: fn((num) => add(num, 5)),
 * });
 *
 * await app.resolve(call('addFive', [3]));
 * // === 8
 * ```
 * This example shows how to call an [[fn]]. See the [[call]] and [[apply]]
 * documentation to learn more about calling callable nodes.
 *
 *
 * @example **Create an [[fn]] with named args**
 * ```js
 * import muster, { call, fn, format } from '@dws/muster';
 *
 * const app = muster({
 *   greet: fn(['name'], ({ name }) =>
 *     format('Hello, ${name}!', { name })
 *   ),
 * });
 *
 * await app.resolve(call('greet', { name: 'Bob' }));
 * // === 'Hello, Bob!'
 * ```
 * This example shows how to create and call an [[fn]] node with named arguments.
 */
export declare function fn(factory: ((...args: Array<ContextNodeDefinition>) => NodeDefinition)): FnNodeDefinition;
export declare function fn(argNames: Array<string>, factory: ((args: NamedFnArgs) => NodeDefinition)): FnNodeDefinition;
export declare function isFnNodeDefinition(value: NodeDefinition): value is FnNodeDefinition;