import type { DocumentSource, FileInput } from './index.js';
import type { FileLoaderOptions } from './text.js';
/** Options for `parseCsv()`. */
export interface CsvParseOptions {
    /** The field separator. Defaults to a comma; use `'\t'` for TSV. */
    delimiter?: string;
}
/**
 * CSV parsed as it arrives: `push()` takes the next piece of text, of any length, and returns the rows
 * it completed; `end()` returns the last. A quote, or a CRLF, split between two pieces is read as one.
 * `parseCsv()` is this, given the whole text at once.
 */
export declare class CsvRowParser {
    private readonly delimiter;
    private row;
    private field;
    private quoted;
    /** A quote inside a quoted field, waiting for the next character: a second quote, or the field's end. */
    private quote;
    /** A carriage return that ended a row, whose line feed, if one follows, belongs to it. */
    private carriage;
    private started;
    constructor(options?: CsvParseOptions);
    /** Reads the next piece of text, and returns the rows it completed. */
    push(text: string): string[][];
    /** Ends the text, and returns its last row, unless it ended with a line break. */
    end(): string[][];
}
/**
 * Parses CSV into rows of fields, following RFC 4180: quoted fields may hold the delimiter, line
 * breaks, and doubled quotes; lines may end in CRLF or LF; and a trailing line break adds no row.
 */
export declare function parseCsv(text: string, options?: CsvParseOptions): string[][];
/** Options for `loadCsv()`. */
export interface CsvLoaderOptions extends FileLoaderOptions, CsvParseOptions {
    /**
     * Columns that make up a row's text, written as `column: value` lines. Defaults to every column not
     * named in `idColumn` or `metadataColumns`.
     */
    textColumns?: readonly string[];
    /** The column whose value becomes the row's id, after the file name. Defaults to the row number. */
    idColumn?: string;
    /** Columns copied into the metadata, where a filter can select on them. */
    metadataColumns?: readonly string[];
}
/**
 * CSV files, one document per row. The first row names the columns. Each row's text lists its columns
 * by name, so a model reading a chunk knows what each value is. Rows are read as the file arrives, so
 * a file larger than memory streams through.
 */
export declare function loadCsv(inputs: FileInput | Iterable<FileInput>, options?: CsvLoaderOptions): AsyncGenerator<DocumentSource>;