Iterator helpers

class Iterator {
  static from(iterable: Iterable<any> | Iterator<any>): Iterator<any>;
  drop(limit: uint): Iterator<any>;
  every(callbackfn: (value: any, counter: uint) => boolean): boolean;
  filter(callbackfn: (value: any, counter: uint) => boolean): Iterator<any>;
  find(callbackfn: (value: any, counter: uint) => boolean)): any;
  flatMap(callbackfn: (value: any, counter: uint) => Iterable<any> | Iterator<any>): Iterator<any>;
  forEach(callbackfn: (value: any, counter: uint) => void): void;
  map(callbackfn: (value: any, counter: uint) => any): Iterator<any>;
  reduce(callbackfn: (memo: any, value: any, counter: uint) => any, initialValue: any): any;
  some(callbackfn: (value: any, counter: uint) => boolean): boolean;
  take(limit: uint): Iterator<any>;
  toArray(): Array<any>;
  @@toStringTag: 'Iterator'
}

CommonJS entry points

core-js/proposals/iterator-helpers-stage-3-2