Enumeratum VS Scalaz

I'm not sure I understand what Cats or cats-effect has to do with what you're trying to do. As far as I can tell, it sounds like what you're asking is simply "what's the best way to implement an enumerated type in Scala?" The best answer to that I'm aware of is Enumeratum.

In Scala 2: enumeratum which is, essentially, option 3 from your post.

And for exactly the same reasons one shouldn't override equals and hashCode in a case class, they shouldn't manually implement an enumeration and instead let a well-tested macro (2.x) or the compiler itself (3.x) handle reliably doing the automated code generation. The more code that is generated by the compiler, the smaller the defects, technical debt, and security vulnerability surface areas.

For Scala, check out the enumeratum library (https://github.com/lloydmeta/enumeratum). In my opinion its the best enum implementation I know of. It has all the features defined in the table, and the syntax is really clean. It even supports unique associated values (eg. unique String/Int keys).

I'm sorry, but have you ever done functional programming for a real company, like in a functional programming language like Haskell, Scala, or F#? Have you ever used Scala cats or scalaz? Have you ever learned category theory and how to apply its abstractions in software? Listen u/judethedude2106 this person hasn't gone as far down the functional programming rabbit hole as I have. Beyond learning the basics like the difference between pure and impure functions, what are closures, what higher order functions are and the most common ones like .map, .filter, and .flatmap, the immutable collections like immutable linked lists and trees, and what a Monad is and common monads like those used for futures/promises, async programming, and Option (Some or None, which is used instead of null checking), the more advanced functional programming stuff like category theory based abstractions are totally useless for real jobs and is just a giant time suck. Don't waste years on functional programming, spend at most a few months on it and no more.

If I managed to gain you interest you can take a look at one of the following libraries like cats, scalaz for scala and vavr for java which contain type class definitions and implementations for common types.

I’ve specifically had 2 job offers internally at my company because of this language. First with Cats and Scalaz and now with ZIO, Scala has taken the best parts of Haskell, the best parts of Scala, and made it really nice to work with. You can barely see the OOP leftovers.