import { NodeApi } from "./interfaces/node-api";
import { TreeApi } from "./interfaces/tree-api";
import { IdObj } from "./types/utils";
export declare function bound(n: number, min: number, max: number): number;
export declare function isItem(node: NodeApi<any> | null): boolean | null;
export declare function isClosed(node: NodeApi<any> | null): boolean | null;
export declare function isOpenWithEmptyChildren(node: NodeApi<any> | null): boolean | null;
/**
 * Is first param a descendant of the second param
 */
export declare const isDescendant: (a: NodeApi<any>, b: NodeApi<any>) => boolean;
export declare const indexOf: (node: NodeApi<any>) => number;
export declare function noop(): void;
export declare function dfs(node: NodeApi<any>, id: string): NodeApi<any> | null;
export declare function walk(node: NodeApi<any>, fn: (node: NodeApi<any>) => void): void;
export declare function focusNextElement(target: HTMLElement): void;
export declare function focusPrevElement(target: HTMLElement): void;
export declare function access<T = boolean>(obj: any, accessor: string | boolean | Function): T;
export declare function identifyNull(obj: string | IdObj | null): string | null;
export declare function identify(obj: string | IdObj): string;
export declare function mergeRefs(...refs: any): (instance: any) => void;
export declare function safeRun<T extends (...args: any[]) => any>(fn: T | undefined, ...args: Parameters<T>): any;
export declare function waitFor(fn: () => boolean): Promise<void>;
export declare function getInsertIndex(tree: TreeApi<any>): number;
export type TreeLineChars = {
    last: string;
    middle: string;
    pipe: string;
    blank: string;
};
/**
 * Generate a tree-line prefix string for a node.
 *
 * Returns characters like `├ `, `└ `, `│` that visually connect
 * parent and child nodes, similar to the Unix `tree` command.
 *
 * **Styling note:** The prefix uses Box Drawing characters (`│`, `├`, `└`)
 * which require a monospace font for correct alignment. Wrap the prefix
 * in a `<span>` with `fontFamily: "monospace"` and use a consistent
 * `fontSize` (e.g. 14–16px). Inherited `line-height` or `font-size`
 * from parent elements can cause misalignment.
 *
 * @example Basic usage
 * ```tsx
 * function MyNode({ node, style }: NodeRendererProps<MyData>) {
 *   return (
 *     <div style={style}>
 *       <span style={{ fontFamily: "monospace", fontSize: 14 }}>
 *         {getTreeLinePrefix(node)}
 *       </span>
 *       {node.data.name}
 *     </div>
 *   );
 * }
 * ```
 *
 * @example With folder/file icons
 * ```tsx
 * function MyNode({ node, style }: NodeRendererProps<MyData>) {
 *   const icon = node.isLeaf ? "📄" : node.isOpen ? "📂" : "📁";
 *   return (
 *     <div style={style}>
 *       <span style={{ fontFamily: "monospace", fontSize: 16 }}>
 *         {getTreeLinePrefix(node)}
 *       </span>
 *       {icon} {node.data.name}
 *     </div>
 *   );
 * }
 * ```
 *
 * @example Custom characters
 * ```tsx
 * // ASCII-only style
 * getTreeLinePrefix(node, { last: "`- ", middle: "|- ", pipe: "|", blank: "  " })
 * ```
 */
export declare function getTreeLinePrefix(node: NodeApi<any>, chars?: Partial<TreeLineChars>): string;
export declare function getInsertParentId(tree: TreeApi<any>): string | null;