Putting lenses to work

I gave a talk a couple of weeks ago at BayHac 2017 on “Putting lenses to work”, to show in a practical context how we use lenses at my workplace. I specifically avoided any theory about lenses, or the complex types, or the many operators, to show that at its core, lens is a truly invaluable library:

The videos are now available on YouTube, and the slides for this talk are on GitHub.

The code in the slides are taken directly (using Emacs) from a test file in that same repository, Lenses.hs, to serve as a way of preserving helpful examples, and to make it easy to cargo cult specific patterns into your code.