/**
 * CronBuilder
 * Create a cron expression using a immutable fluent builder.
 */
import type { CronObject, CronTuple, SpecialAlias } from './types';
/** Immutable fluent builder for cron expressions. */
export declare class CronBuilder {
  private static parser;
  private readonly state;
  private readonly field?;
  /**
   * Create a builder instance from a optional cron expression.
   *
   * @param expr - Optional standard 5-field cron string, a partial cron object or special alias.
   * @returns The current cron builder instance.
   *
   * @example
   * CronBuilder.create()
   * CronBuilder.create( '0 2 0 JAN MON-FRI' )
   * CronBuilder.create( { minute: '30', hour: '1' } )
   * CronBuilder.create( '@daily' )
   */
  static create(expr?: string | SpecialAlias | Partial<CronObject>): CronBuilder;
  private constructor();
  /** Get the currently selected field definition. */
  private get def();
  /** Ensure a cron field has been selected. */
  private requireField;
  /** Create a new builder with updated state. */
  private next;
  /** Resolve any input into a cron field expression string. */
  private resolve;
  /** Validate a cron field value against its allowed range. */
  private validate;
  /** Clamp a cron field value to its allowed range. */
  private clamp;
  /** Build a field expression string. */
  private buildExpr;
  /** Update the current cron field. */
  private set;
  /** Select the minute field. */
  minute(): CronBuilder;
  /** Select the hour field. */
  hour(): CronBuilder;
  /** Select the day of month field. */
  dayOfMonth(): CronBuilder;
  /** Select the month field. */
  month(): CronBuilder;
  /** Select the day of week field. */
  dayOfWeek(): CronBuilder;
  /** Set explicit value. */
  value(value: string | number): CronBuilder;
  /** Set full list of values. */
  list(...values: (string | number)[]): CronBuilder;
  /** Define a range (min -> max). */
  range(from: number, to: number): CronBuilder;
  /** Define step expression. */
  every(step: number, range?: [number, number]): CronBuilder;
  /** Output as structured cron object. */
  toObject(): CronObject;
  toTuple(): CronTuple;
  /** Output as standard 5-field cron expression string. */
  toString(): string;
}