Chapter 7 Challenge -- my version vs the book version

[chadpengar]

The challenge is to update the earlier phone dialer to handle letters as well. It suggests that we use .unwrap from RxSwiftExt to handle nils from the convert process. I thought that was what .compactMap does?

I ended up with

  input
    .compactMap { convert($0) }
    .skipWhile {  $0 == 0 }
    .filter { $0 < 10 }
    .take(10)
    .toArray()
    .map(format)
    .map(dial)
    .subscribe( onSuccess: { number in
        print(number)
    })
    .disposed(by: disposeBag)

The “official” challenge answer in the download has

  input.asObservable()
    .map(convert)
    .unwrap()
    .skipWhile { $0 == 0 }
    .take(10)
    .toArray()
    .map(format)
    .map(dial)
    .subscribe(onSuccess: {
      print($0)
    })
    .disposed(by: disposeBag)

Both give the same result when I run them. In my quest to learn the “correct” way, the Rx way, I am wondering why the book answer is as it is and why it would be better than my way?

(Yes I get that I can dispense with the filter since the convert, nil removed, does that for me)

Thanks