/**
 * Nesting helpers
 *
 * Convert flat tabular shapes into the nested children-array shape consumed
 * by hierarchical components (TreeTable, Tree).
 *
 *   nestByPath     — rows with a separator-delimited path field
 *   nestByColumns  — rows with one or more group-by columns
 */
/**
 * Convert flat rows that carry a separator-delimited path string into
 * nested rows with a `children` array.
 *
 * Synthesizes intermediate parent rows when a path segment has no own row
 * — the synthetic row carries only the path-field set to the partial path.
 *
 * @param {Array<Record<string, unknown>>} rows
 * @param {{ column: string, separator?: string, keepPath?: boolean }} options
 * @returns {Array<Record<string, unknown>>}
 */
export function nestByPath(rows: Array<Record<string, unknown>>, { column, separator, keepPath }: {
    column: string;
    separator?: string;
    keepPath?: boolean;
}): Array<Record<string, unknown>>;
/**
 * Convert flat rows into nested rows by grouping on one or more columns.
 *
 * Each entry in `columns` produces a level of grouping. Synthesized group
 * rows carry `__group: true`, the grouped column name on a `__column` key,
 * and the column value under the column's own field name so cell snippets
 * can read it normally.
 *
 * @param {Array<Record<string, unknown>>} rows
 * @param {string[]} columns
 * @param {{ groupRowFactory?: (col: string, value: unknown, children: Array) => Record<string, unknown> }} [options]
 * @returns {Array<Record<string, unknown>>}
 */
export function nestByColumns(rows: Array<Record<string, unknown>>, columns: string[], options?: {
    groupRowFactory?: (col: string, value: unknown, children: any[]) => Record<string, unknown>;
}): Array<Record<string, unknown>>;