/**
 * CSV Formatter
 *
 * Core formatting functions for converting data to CSV strings.
 *
 * Low-level exports:
 * - formatField(): Format a single field value
 * - formatRowWithLookup(): Format an entire row (used by CsvFormatterStream)
 * - applyTypeTransform(): Apply type-based transforms
 * - defaultToString(): Default value-to-string conversion
 *
 * High-level exports:
 * - formatCsv(): Batch format data to CSV string
 *
 * Features:
 * - Multiple input types (objects, arrays, RowHashArray)
 * - Flexible quoting (per-column, per-header, always, disabled)
 * - Type transforms with context
 * - Formula escaping (CSV injection protection)
 * - BOM support
 */
import type { CsvFormatOptions, Row, TypeTransformMap, TransformContext, TransformResult } from "../types.js";
import { type DecimalSeparator } from "../utils/number.js";
import type { CsvFormatRegex, FormatFieldContext, FormatRowOptions } from "./config.js";
/**
 * Apply type-based transform to a single value.
 * Returns the transformed result, or undefined if no transform applies.
 */
export declare function applyTypeTransform(value: any, transform: TypeTransformMap, ctx: TransformContext): TransformResult;
/**
 * Default type conversion to string.
 */
export declare function defaultToString(value: any, decimalSeparator: DecimalSeparator): string;
/**
 * Format a single field value to CSV string
 */
export declare function formatField(value: unknown, regex: CsvFormatRegex, ctx: FormatFieldContext): string;
/**
 * Format an entire row to CSV string.
 *
 * Performance optimizations:
 * - Uses for loop with direct string building instead of map().join()
 * - Reuses a single mutable context object instead of creating one per field
 */
export declare function formatRowWithLookup(row: unknown[], regex: CsvFormatRegex, options: FormatRowOptions): string;
/**
 * Format data as CSV string.
 *
 * Performance optimization: Builds result string directly without
 * intermediate arrays from map().join() operations.
 *
 * @example
 * ```ts
 * // Array of arrays
 * formatCsv([["a", "b"], ["1", "2"]])
 * // "a,b\n1,2"
 *
 * // Array of objects
 * formatCsv([{ name: "Alice", age: 30 }])
 * // "name,age\nAlice,30"
 *
 * // With options
 * formatCsv(data, {
 *   delimiter: ";",
 *   quoteColumns: { name: true },
 *   escapeFormulae: true,
 *   bom: true
 * })
 * ```
 */
export declare function formatCsv(data: Row[] | Record<string, unknown>[], options?: CsvFormatOptions): string;