interface IndexReaderCollection extends ReaderCollectionInput, ReaderCollection, IndexReaderCollectionInput {
  /**
   *判断给定的key是否有对应记录
   */
  existAt: (i: number) => <A>(f: Kind<F, A>) => boolean
  /**
   *得到第一个满足条件的key
   */
  findFirstIndex: <A>(predicate: Predicate<A>) => (f: Kind<F, A>) => Option<number>
  /**
   *遍历每一个元素
   *函数返回false时，中断遍历
   */
  forEachIndex: <A>(f: PredicateWithIndex<number, A>) => (as: Kind<F, A>) => void
  /**
   *从集合中用key得到记录
   */
  getAt: (i: number) => <A>(f: Kind<F, A>) => Option<A>
  /**
   *判断是否所有元素都满足条件
   */
  everyIndex<A>(predicate: PredicateWithIndex<number, A>): (as: Kind<F, A>) => boolean
  /**
   *得到一个满足条件的key数组
   */
  findIndex<A>(predicate: Predicate<A>): (as: Kind<F, A>) => number[]
  /**
   *得到最后一个满足条件的key
   */
  findLastIndex<A>(predicate: Predicate<A>): (as: Kind<F, A>) => Option<number>
  /**
   *判断是否有一个元素都满足条件
   */
  someIndex<A>(predicate: PredicateWithIndex<number, A>): (as: Kind<F, A>) => boolean
}

interface IndexReaderCollectionInput {
  /**
   *用key读取集合数据
   */
  _getAt: (i: number) => <A>(f: Kind<URI, A>) => A | undefined | null
}