import type { DocumentSource, FileInput } from './index.js';
import type { FileLoaderOptions } from './text.js';
/** Options for `loadJson()`. */
export interface JsonLoaderOptions extends FileLoaderOptions {
    /**
     * Picks the records out of the parsed file, which is then read whole. Defaults to the items of the
     * array at `recordsAt`, or of a top-level array, read as the file arrives; or else the value itself as
     * one record.
     */
    records?: (value: unknown) => Iterable<unknown>;
    /**
     * Where the array of records is: object keys from the top, dotted, such as `data.items`. Its items
     * are read one at a time as the file arrives, so a file larger than memory streams through. A file
     * with no array there is refused.
     */
    recordsAt?: string;
    /**
     * A record's text: a field, by dotted path such as `body.text`, or a function. Defaults to a string
     * record itself, or else the record as indented JSON.
     */
    text?: string | ((record: unknown) => string);
    /** A record's id, after the file name: a field by dotted path, or a function. Defaults to its position. */
    id?: string | ((record: unknown, index: number) => string);
    /** Fields copied into the metadata, by dotted path, or a function that builds it. */
    metadataFields?: readonly string[] | ((record: unknown) => Record<string, unknown>);
    /**
     * Reads one JSON value per line (JSON Lines). Defaults to on for `.jsonl` and `.ndjson` files, so a
     * large export streams record by record.
     */
    lines?: boolean;
}
/**
 * JSON and JSON Lines files, one document per record. A JSON Lines file, and the array of records in a
 * JSON one, are read as the file arrives, a record at a time, so a file larger than memory streams
 * through; a `records` function reads the file whole.
 */
export declare function loadJson(inputs: FileInput | Iterable<FileInput>, options?: JsonLoaderOptions): AsyncGenerator<DocumentSource>;