[creichert]

Yesod would be the closest to Rails.

Scotty would be closer to Sinatra and Flask. Spock is similar to Scotty but comes with a few more built-in features like type-safe routing, sessions, etc.

I recommend Yesod but there are certainly some advanced metaprogramming features (routing, models).

Have you checked out the Yesod scaffold site? https://github.com/yesodweb/yesod-scaffold