/*!
 * Copyright 2020 Ron Buckton
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import type { GraphNode } from "./graphNode";
import type { GraphSchema } from "./graphSchema";
import type { Graph } from "./graph";
import { GraphObject } from "./graphObject";
/**
 * Represents a link between two nodes in the graph.
 */
export declare class GraphLink extends GraphObject {
    private _source;
    private _target;
    private _index;
    private constructor();
    /**
     * Gets the graph that this object belongs to.
     */
    get owner(): Graph;
    /**
     * Gets the document schema for this object.
     */
    get schema(): GraphSchema;
    /**
     * The source of the link.
     */
    get source(): GraphNode;
    /**
     * The target of the link.
     */
    get target(): GraphNode;
    /**
     * An optional index for the link (default `0`).
     */
    get index(): number;
    /**
     * Gets a value indicating whether this is a containment link.
     */
    get isContainment(): boolean;
    /**
     * Gets or sets a descriptive label to associate with this link.
     */
    get label(): string | undefined;
    set label(label: string | undefined);
    /**
     * Creates an iterator for the links related to this link.
     * @param searchDirection Either `"source"` to find related links across the incoming links of sources, or `"target"` to find related links across the outgoing links of targets.
     * @param traversal An object that specifies callbacks used to control how links are traversed and which links are yielded during iteration.
     */
    related(searchDirection: "source" | "target", traversal?: GraphLinkTraversal): IterableIterator<GraphLink>;
    /**
     * Removes this link from the graph.
     */
    deleteSelf(): boolean;
}
export interface GraphLinkTraversal {
    /**
     * A callback used to determine whether a link should be traversed. If not specified, all links are traversed.
     */
    traverseLink?: (this: void, link: GraphLink) => boolean;
    /**
     * A callback used to determine whether a link should be yielded. If not specified, all links are yielded.
     */
    acceptLink?: (this: void, link: GraphLink) => boolean;
}