Lisp-style cons-based list

cons-list.ts

type List<T1> = [T1, List<T1> | null];

function* iterateCons<T>([left, right]: List<T>): IterableIterator<T> {
  if (right) {
    yield* iterateCons(right);
  }
  yield left;
}

const cons = <T1, T2>(left: T1, right: T2): [T1, T2] => [left, right];

const list = <T>(l?: List<T>) => ({
  append: (v: T) => list(cons(v, l ?? null)),
  [Symbol.iterator]: () =>
    l ? iterateCons(l) : { next: () => ({ value: null, done: true }) },
});