> cats or zio are basically ports of Haskel into Scala
Not really. And ZIO takes special pride in that not being the case.
That's not to say that the authors didn't know (about) Haskell and its libraries. But these are distinctly Scala takes on the topic. Especially ZIO, heavily relying subtyping and vairance, is very far from Haskell while still being pure FP.
ZIO's "FP" library called "ZIO Prelude" totally revamps the "traditional" Type Class hierarchy, using Scala's intersection types feature. The name ("Prelude") is the only Haskellism there :)
https://www.youtube.com/watch?v=OwmHgL9F_9Q
https://zio.github.io/zio-prelude/docs/overview/overview_dia...
https://github.com/zio/zio-prelude/
