import { NodeDefinition, StatelessGraphNode, StatelessNodeDefinition, StatelessNodeType } from '../../types/graph';
/**
 * An instance of the [[param]] node.
 * See the [[param]] documentation to find out more.
 */
export interface ParamNode extends StatelessGraphNode<'param', ParamNodeProperties> {
}
/**
 * A definition of the [[param]] node.
 * See the [[param]] documentation to find out more.
 */
export interface ParamNodeDefinition extends StatelessNodeDefinition<'param', ParamNodeProperties> {
}
export interface ParamNodeProperties {
    name: string;
}
/**
 * The implementation of the [[param]] node.
 * See the [[param]] documentation to learn more.
 */
export declare const ParamNodeType: StatelessNodeType<'param', ParamNodeProperties>;
/**
 * Creates instance of the [[param]] node, which is used for accessing the value of a parameter from the current scope.
 * Parameters are usually defined by a [[tree]] and **match** helper. See the [[tree]] documentation for more information.
 *
 * @example **Accessing parameter values**
 * ```js
 * import muster, { match, param, ref, types } from '@dws/muster';
 *
 * const app = muster({
 *   user: {
 *     [match(types.string, 'userId')]: param('userId'),
 *   },
 *   invalidParam: param('userId'),
 * });
 *
 * const userId = await app.resolve(ref('user', '123-456'));
 * // userId === '123-456'
 *
 * const invalid = await app.resolve(ref('invalidParam'));
 * // invalid === 'Invalid parameter: "userId"'
 * ```
 * This example demonstrates how to access a named parameter from the current path. Usually the
 * [[param]] resolves to a [[value]] with the value of a given parameter. See the
 * [[tree]] for more information on matchers and branches.
 */
export declare function param(name: string): ParamNodeDefinition;
export declare function isParamNodeDefinition(value: NodeDefinition): value is ParamNodeDefinition;