import { AggregateType } from '../models/Column';
/**
 * Reduce a set of item values to a single aggregate. `count` returns the item
 * count; the numeric aggregates read each value through `getValue`, skip
 * null/non-numeric entries, and return null when nothing numeric is present.
 */
export declare function computeAggregate<T>(items: T[], type: AggregateType, getValue: (item: T) => unknown): number | null;