"Well, the good news is that I didn’t fall asleep. The bad news is that I probably should have: this WWDC keynote clocked in over two hours long. This was shorter than last year, but it felt longer. That one had iMacs and iPads and HomePods, oh my. This had… well, we’ll get to that. But even for a keynote chock-full of announcements, two hours is pushing it for a single event. I find 90 minutes to be preferable for busy ones. And I believe this one could have been pretty comfortably done in an hour..."
An Xcode playground demonstrating the new features in Swift 4.2.