utils

export interface IIdxMap {
  prev: number
  now: number
  next: number
}

export interface IThreadConfig {
  arrCopy: any[]
  idxMap: IIdxMap
  ___: any
}

export type TReducer<T, U> = (acc: T[], cur: T | ReturnType<TTransformFn<T, U>>) => U[]

export declare type TTransformFn<A, B> = (arg: A, config: IThreadConfig) => B