import { EastFunction, FromCsvFunction, FromCsvOptions, ToCsvFunction, ToCsvOptions, Utf8DecodeFunction, Utf8EncodeFunction, Variable } from '../functions';
import { ArrayType, BlobType, NonNullable, StringType, StructType } from '../types';
/**
 * Return a blob containing a CSV encoding of an array of structs.
 *
 * @param value the {@link Expression} with the value to encode as CSV
 * @param printers an object containing functions returning {@link Expression}s to print each field (e.g. to format a date-time)
 * @param options provide options for formatting the CSV files (such as delimeters, null sentinels, and headers)
 *
 * @category Expression
 *
 * @example
 * ```typescript
 * ToCsv(
 *   array_of_structs,
 *   { date: x => Print(x, "YYYY-MM-DD") },
 *   { nullString: "NA" }
 * )
 * ```
 */
export declare function ToCsv<T extends ArrayType<StructType>>(value: EastFunction<T>, printers?: {
    [K in keyof T["value"]["value"]]?: (field: Variable<NonNullable<T["value"]["value"][K]>>) => EastFunction<StringType>;
}, options?: Partial<ToCsvOptions>): ToCsvFunction<BlobType>;
/**
 * Return a array of structs from data encoded in a CSV blob.
 *
 * @param type the {@link EastType} of the output to decode (column names should match the CSV file)
 * @param value the {@link Expression} with the blob value to decode from CSV
 * @param parsers an object containing functions returning {@link Expression}s to parse each field (e.g. to parse the format a date-time)
 * @param options provide options for formatting the CSV files (such as delimeters, null sentinels, and headers)
 *
 * @example
 * ```typescript
 * FromCsv(
 *   ArrayType(StructType({ id: StringType, date: DateTimeType, qty: Nullable(IntegerType) })),
 *   blob,
 *   { date: x => Parse(x, "YYYY-MM-DD") },
 *   { nullString: "NA" }
 * )
 * ```
 * @category Expression
 */
export declare function FromCsv<T extends ArrayType<StructType>>(type: T, value: EastFunction<BlobType>, parsers?: {
    [K in keyof T["value"]["value"]]?: (field: Variable<StringType>) => EastFunction<NonNullable<T["value"]["value"][K]>>;
}, options?: Partial<FromCsvOptions>): FromCsvFunction<T>;
/**
 * Return a blob containing a string encoded as a UTF8 bytestring.
 *
 * @param from the {@link EastFunction} of the string to encode
 *
 * @category Expression
 *
 * @example
 * ```typescript
 *  // ...
 *  Blob: Utf8Encode(string),
 *  // ...
 * ```
 */
export declare function Utf8Encode<T extends StringType>(from: EastFunction<T>): Utf8EncodeFunction<BlobType>;
/**
 * Return a blob containing a string encoded as a UTF8 bytestring.
 *
 * @param from the {@link EastFunction} of the string to encode
 *
 * @category Expression
 *
 * @example
 * ```typescript
 *  // ...
 *  String: Utf8Decode(blob),
 *  // ...
 * ```
 */
export declare function Utf8Decode<T extends BlobType>(from: EastFunction<T>): Utf8DecodeFunction<StringType>;