If this post got you interested in learning more about Haskell and you want to see type classes in some real code, a great starting point for Haskell is IHP :)

IHP is a new Haskell framework with a focus on actual building applications. Imagine the productiveness of rails combined with the typesafety of Haskell.

It's now already the biggest Haskell web framework, we just hit 3200 GitHub stars. I belive Haskell can reach a lot more than it's currently doing if we get things easy to use.

If you want to build a web app with Haskell and play with type classes check it out: https://ihp.digitallyinduced.com/ GitHub: https://github.com/digitallyinduced/ihp