import { TreeNode, Identity } from './interface';
import { SimpleNodeContext } from './context';
export declare function array2tree_byLevel<A extends {
    id: any;
    level: number;
}>(arr: A[], options?: {
    rootId: any;
}): TreeNode<A>;
export declare function array2tree_byPid<A extends {
    id: any;
    pid: any;
}>(arr: A[], options?: {
    pidField?: string;
    rootId?: any;
}): TreeNode<A>;
export declare function tree2Array<A extends Identity>(tree: TreeNode<A>, attachContextKeys?: keyof SimpleNodeContext): Omit<TreeNode<A>, 'children'>[];