Personally, I prefer

    setTimeout -> (
      alert "later"
      alert "later"
      alert "later"
      ), 300

to

    setTimeout(-> 
      alert "later"
      alert "later"
      alert "later"
      , 300)

I think it's much more clear and close to how we write JS code:

    setTimeout(function() {
      alert("later");
      alert("later");
      return alert("later");
    }, 300);