import { State } from "./externals";
import { TimerInternal } from "./internals";
interface StartAction {
    type: "start";
    startTime: number;
}
interface StopAction {
    type: "stop";
    stopTime: number;
}
export declare type Actions = StartAction | StopAction;
declare type ReducerFnType = (timer: TimerInternal, currentState?: State, action?: Actions) => State;
/**
 * @throws TimerErrors
 */
export declare const reducerFn: ReducerFnType;
export {};