import { type MutGraph } from ".";
/**
 * an accessor specifying how to get the children from a node
 *
 * The interface for getting child data from node data. This function must
 * return data for every child given the data for the current node. `i` will
 * increment for each node processed.
 *
 * Can be modified with {@link Hierarchy#children}.
 */
export type Children<in out NodeDatum> = (datum: NodeDatum, index: number) => Iterable<NodeDatum> | undefined;
/**
 * The interface for getting children data and associated link data from node
 * data. This function must return data for every child of the given node, and
 * data for link between the two. `i` will increment for each node processed.
 *
 * Can be modified with {@link Hierarchy#childrenData}.
 */
export type ChildrenData<in out NodeDatum, out LinkDatum = unknown> = (datum: NodeDatum, index: number) => Iterable<readonly [NodeDatum, LinkDatum]> | undefined;
/**
 * a wrapped children operator that functions as a children data operator
 *
 * When creating a {@link Hierarchy} with a children operator, the
 * corresponding {@link Hierarchy#childrenData} will be wrapped in this. This
 * version returns undefined for all link data.
 */
export interface WrappedChildren<NodeDatum, Child extends Children<NodeDatum>> extends ChildrenData<NodeDatum, undefined> {
    /** the wrapped children operator */
    wrapped: Child;
}
/**
 * a wrapped children data operator that functions as a children operator
 *
 * When creating a {@link Hierarchy} with a children data operator, the
 * corresponding {@link Hierarchy#children} will be wrapped in this.
 */
export interface WrappedChildrenData<NodeDatum, ChildData extends ChildrenData<NodeDatum>> extends Children<NodeDatum> {
    /** the wrapped children data operator */
    wrapped: ChildData;
}
/**
 * create a {@link MutGraph} from hierarchical data
 *
 * By default, each piece of data passed in corresponds to a node, and their
 * `children` will be explored recursively creating more nodes. Use
 * {@link children} to change how children are found, or {@link childrenData}
 * to also attach link data.
 *
 * Created with {@link graphHierarchy}.
 */
export interface Hierarchy<NodeDatum, LinkDatum, Child extends Children<NodeDatum>, ChildData extends ChildrenData<NodeDatum, LinkDatum>> {
    /**
     * construct a graph from hierarchical data
     *
     * @param data - a source node to recursively find children of; you can pass
     *   multiple source nodes for disconnected or multi-rooted graphs
     * @returns graph - a graph of the hierarchical data
     */
    (...data: readonly NodeDatum[]): MutGraph<NodeDatum, LinkDatum>;
    /**
     * set a new children accessor
     *
     * This accessor takes passed in node data and returns an iterable of new
     * node data that correspond to that nodes children. When this is specified,
     * link data are left undefined.
     *
     * Due to the way typescript inference happens, to make this accessor valid
     * you will likely have to define a separate interface for the data type so
     * that the recursive definition of children can be specified.
     *
     * The default accessor is:
     * ```ts
     * ({ children }) => children
     * ```
     */
    children<NewNode, NewChildren extends Children<NewNode>>(val: NewChildren & Children<NewNode>): Hierarchy<NewNode, undefined, NewChildren, WrappedChildren<NewNode, NewChildren>>;
    /**
     * get the current children accessor
     *
     * This is the current {@link Children}. If {@link childrenData} was specified,
     * this will return a {@link WrappedChildrenData | wrapped version}
     * that returns only the children of that operator.
     */
    children(): Child;
    /**
     * set a new children data accessor
     *
     * This accessor takes passed in node data and returns an iterable with
     * tuples of new node data and the link data for the corresponding link.
     * Use this function when your graph data has link information that you want
     * to preserve in the graph structure for easy access from links.
     *
     * @example
     *
     * ```ts
     * (nodeData) => [[childData, linkData]]
     * ```
     */
    childrenData<NewNode, NewLink, NewChildrenData extends ChildrenData<NewNode, NewLink>>(data: NewChildrenData & ChildrenData<NewNode, NewLink>): Hierarchy<NewNode, NewLink, WrappedChildrenData<NewNode, NewChildrenData>, NewChildrenData>;
    /**
     * get the current children data accessor
     *
     * This is the current {@link ChildrenData}. If {@link children} was
     * specified, this will return a
     * {@link WrappedChildren | wrapped version} that returns undefined
     * for all link data.
     */
    childrenData(): ChildData;
}
/** an object with children */
export interface HasChildren {
    /** the children */
    readonly children?: Iterable<HasChildren> | undefined;
}
/**
 * the default {@link Hierarchy} operator created by {@link graphHierarchy}
 */
export type DefaultHierarchy = Hierarchy<HasChildren, undefined, Children<HasChildren>, WrappedChildren<HasChildren, Children<HasChildren>>>;
/**
 * create a new {@link Hierarchy} with default settings
 *
 * Hierarchy operators create graphs from data that are already in a graph like
 * form. By default it expects node data to have a `children` property with
 * more node data.
 *
 * You can specify a different way to access children with
 * {@link Hierarchy#children} or also specify link data with
 * {@link Hierarchy#childrenData}.
 *
 * @example
 *
 * If you want to make simple graph with default settings:
 *
 * ```ts
 * const data = {
 *   "id": "Euler",
 *   "children": [
 *     {
 *       "id": "Lagrange",
 *       "children": [
 *         {
 *           "id": "Fourier"
 *         },
 *         {
 *           "id": "Poisson",
 *           "children": [ { "id": "Dirichlet" } ]
 *         }
 *       ]
 *     }
 *   ]
 * } as const;
 *
 * const builder = graphHierarchy();
 * const grf = builder(data);
 * ```
 *
 * @example
 *
 * If you want to make a graph with link data:
 *
 * ```ts
 * const data = {
 *   "id": "Euler",
 *   "children": [
 *     [
 *       { "id": "Lagrange" },
 *       "advisee",
 *     ]
 *   ]
 * } as const;
 *
 * interface Data {
 *   children?: [Data, string][];
 * }
 *
 * const builder = graphHierarchy()
 *   .childrenData(({ children = [] }: Data) => children);
 * const grf = builder(data);
 * ```
 */
export declare function graphHierarchy(...args: never[]): DefaultHierarchy;