import { NodeDefinition, StatelessGraphNode, StatelessNodeDefinition, StatelessNodeType } from '../../types/graph';
/**
 * An instance of the [[isNil]] node.
 * See the [[isNil]] documentation to find out more.
 */
export interface IsNilNode extends StatelessGraphNode<'is-nil', IsNilNodeProperties> {
}
/**
 * A definition of the [[isNil]] node.
 * See the [[isNil]] documentation to find out more.
 */
export interface IsNilNodeDefinition extends StatelessNodeDefinition<'is-nil', IsNilNodeProperties> {
}
export interface IsNilNodeProperties {
    target: NodeDefinition;
}
/**
 * The implementation of the [[isNil]].
 * See the [[isNil]] documentation to learn more.
 */
export declare const IsNilNodeType: StatelessNodeType<'is-nil', IsNilNodeProperties>;
/**
 * Creates an instance of an [[isNil]] node, which is a node used when checking if a given target is [[nil]].
 *
 * @example **Check if target node is nil**
 * ```js
 * import muster, { isNil, nil, ref, value } from '@dws/muster';
 *
 * const app = muster({
 *   currentValue: value('some current value'),
 *   previousValue: nil(),
 * });
 *
 * await app.resolve(isNil(ref('currentValue'))); // === false
 *
 * await app.resolve(isNil(ref('previousValue'))); // === true
 * ```
 * This example shows how to check if a given node is [[nil]](or resolves to a [[nil]]).
 */
export declare function isNil(target: NodeDefinition): IsNilNodeDefinition;
export declare function isIsNilNodeDefinition(value: NodeDefinition): value is IsNilNodeDefinition;