Comment by danabramov

How do you do this with callbacks?

    foreach (var player in players) {
        while (true) {
           var name = await Ask("What's your name");
           if (IsValidName(name)) {
               player.name = name;
               break;
           }
        }
    }

Assuming `Ask` is an asynchronous operation and must not block the UI thread.

Note that second player is only asked after the first player has given a valid name.

(And the code structure reflects that :-)

My point is of course it's doable with callbacks, but I spent more time indenting this code than writing it, and I darn well know I'm not smart enough to spell out the correct callback-style code in a comment field on Hacker News. And if I suddenly had to add error handling...