import { AsyncRow, Cells } from './row.js';
import { OrderBy } from './sort.js';
/**
 * Function that gets values in a column.
 *
 * If start and end are provided, only get values in that range.
 * Negative start and end are allowed.
 *
 * @param column Column name
 * @param start Start index (inclusive)
 * @param end End index (exclusive)
 *
 * @returns Values in the column
 */
export type GetColumn = ({ column, start, end }: {
    column: string;
    start?: number;
    end?: number;
}) => Promise<any[]>;
/**
 * Streamable row data
 */
export interface DataFrame {
    header: string[];
    numRows: number;
    rows({ start, end, orderBy }: {
        start: number;
        end: number;
        orderBy?: OrderBy;
    }): AsyncRow[];
    getColumn?: GetColumn;
    sortable?: boolean;
}
/**
 * Return getColumn() function to apply on a DataFrame.
 *
 * Uses df.getColumn() if provided. Otherwise, it creates a naive implementation that
 * fetches full rows (AsyncRow) then extracts the column values.
 *
 * It will benefit of cached rows:
 * ```
 * const getColumn = getGetColumn(rowCache(data))
 * ```
 *
 * @param data DataFrame to add getColumn method to
 * @returns getColumn function
 */
export declare function getGetColumn(data: DataFrame): GetColumn;
export declare function getRanks({ data, column }: {
    data: DataFrame;
    column: string;
}): Promise<number[]>;
export declare function computeDataIndexes(orderBy: {
    direction: 'ascending' | 'descending';
    ranks: number[];
}[]): number[];
export declare function getUnsortedRanks({ data }: {
    data: DataFrame;
}): Promise<number[]>;
/**
 * Wraps a DataFrame to make it sortable.
 *
 * If the DataFrame is already sortable, it will return the original DataFrame.
 *
 * It takes advantage of cached rows to sort the data faster:
 * ```
 * const df = sortableDataFrame(rowCache(data))
 * ```
 *
 * If .getColumn() exists, it's used to sort the rows by the provided column.
 *
 * @param data DataFrame to make sortable
 * @returns DataFrame with sortable rows
 */
export declare function sortableDataFrame(data: DataFrame): DataFrame;
export declare function arrayDataFrame(data: Cells[]): DataFrame;