This is a non-TDD object oriented approach to Uncle Bob's bowling game kata.
http://www.butunclebob.com/ArticleS.UncleBob.TheBowlingGameKata
It took about 2-3 hours including looking up some Kotlin stuff as I'm fairly new to it.
Note that I did intentionally have the main function only call roll with the same argument as in the kata.
I intend to use this in comparisons of TDD to waterfall.