/** One spreadsheet cell; `null` and `undefined` write an empty cell. */
export type TabularCell = string | number | boolean | null | undefined;
interface TabularColumnBase<Row, K extends keyof Row> {
    /** Row field the cell reads, the same `key` a table column uses. */
    readonly key: K;
    /** Text of the header line. */
    readonly header: string;
    /** Turns the field into a cell; required when the field is not a scalar. */
    readonly format?: (value: Row[K], row: Row) => TabularCell;
    /** Default true: formula-like text gets a leading `'` so it is shown, not run. */
    readonly escapeFormulas?: boolean;
}
/** One exported column; `format` is required when the field is not a scalar. */
export type TabularColumn<Row> = {
    [K in keyof Row & string]: Row[K] extends TabularCell ? TabularColumnBase<Row, K> : TabularColumnBase<Row, K> & {
        readonly format: (value: Row[K], row: Row) => TabularCell;
    };
}[keyof Row & string];
/** Options for `toCsv`. */
export interface ToCsvOptions {
    /** Prepends a UTF-8 byte-order mark so Excel reads non-ASCII. Default false. */
    readonly bom?: boolean;
}
/** RFC 4180 CSV: header line, then one CRLF-separated line per row. */
export declare function toCsv<Row extends object>(rows: readonly Row[], columns: readonly TabularColumn<Row>[], { bom }?: ToCsvOptions): string;
/** Replaces path and reserved characters with `-`; caps at 80 characters, keeping the extension. */
export declare function safeFileName(fileName: string): string;
/** Saves `blob` as `safeFileName(fileName)`, then revokes its object URL. */
export declare function downloadBlob(blob: Blob, fileName: string): void;
export {};