A rewrite of the tutorial's Ruby example programs in production-code style

[Mark D Blackwell]

For (at least) my own learning purposes, I borrowed and rewrote all eighteen of the tutorial's Ruby example programs, and converted them to a style that might be used in production code. I blogged about it, here:

https://markdblackwell.blogspot.com/2019/03/a-rewrite-of-example-ruby-programs.html

Criticisms welcome!