import { GraphNode, NodeDefinition, NodeDependency, StatefulGraphNode, StatefulNodeDefinition, StatefulNodeType } from '../../types/graph';
/**
 * An instance of the [[once]] node.
 * See the [[once]] documentation to find out more.
 */
export interface OnceNode extends StatefulGraphNode<'once', OnceNodeProperties, OnceNodeState, OnceNodeData> {
}
/**
 * A definition of the [[once]] node.
 * See the [[once]] documentation to find out more.
 */
export interface OnceNodeDefinition extends StatefulNodeDefinition<'once', OnceNodeProperties, OnceNodeState, OnceNodeData> {
}
export interface OnceNodeProperties {
    target: NodeDefinition | GraphNode | NodeDependency;
}
export interface OnceNodeState {
    currentValue: NodeDefinition | GraphNode;
}
export interface OnceNodeData {
}
/**
 * The implementation of the [[once]] node.
 * See the [[once]] documentation to learn more.
 */
export declare const OnceNodeType: StatefulNodeType<'once', OnceNodeProperties, OnceNodeState, OnceNodeData>;
/**
 * Creates a new instance of a [[once]], which is a type of a [[GraphNode]] that causes a given operation to be
 * performed only once. Used by the [[call]] node to prevent action from re-triggering every time a dependency is changed.
 *
 *
 * @example **Compute the value only once**
 * ```ts
 * import muster, { computed, once, ref, set, variable } from '@dws/muster';
 *
 * const app = muster({
 *   name: variable('Bob'),
 *   greeting: computed([once(ref('name'))], (name) => `Hello, ${name}`),
 * });
 *
 * app.resolve(ref('greeting')).subscribe((greeting) => {
 *   console.log(greeting);
 * });
 *
 * console.log('Changing name to Jane');
 * await app.resolve(set('name', 'Jane'));
 *
 * // Console output:
 * // Hello, Bob
 * // Changing name to Jane
 * ```
 * This example shows how to use the [[once]] to ensure the value of a [[computed]] gets
 * computed only once and doesn't change when the `name` changes.
 */
export declare function once(target: NodeDefinition | GraphNode | NodeDependency): OnceNodeDefinition;
export declare function isOnceNodeDefinition(value: NodeDefinition): value is OnceNodeDefinition;