This is a line-by-line port of Nathan Gitter's Fluent Interfaces project that shows how to implement the various idioms that Apple showed on their "Fluid Interfaces" talk at WWDC 2018.
This is still missing a couple of ports, but figured I could open it up now for people to try out. And I messed up the layout for some controls in one of the samples, need to fix that.
Nathan wrote a blog post with all the juicy details. He tweets as https://twitter.com/nathangitter.
The LICENSE reflects the same license that Nathan used