[shinzui]

Lens is one of my favorite libraries, but I can understand why optics, in general, is a divisive topic. Like many things in Haskell, you won't appreciate optics without suffering through a steep learning curve.

Optics don't just save you a few keystrokes. Instead, they make tedious code that you would never write trivial. And more importantly, they're composable. So it's impossible to appreciate their effectiveness without using them on a real-world app. For example, I've worked in an app with three layers, each with its record types, and without the lens library, the pain of converting between records would have been insufferable. Instead, most developers would couple the three layers together to avoid the problem, which makes the codebase brittle.

[ablob]

Do you know of an application I could look at to see this first hand?