Does anyone here (intentionally) use Scala without an effects library such as Cats or ZIO? Or without going "full Haskell"?

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  • frameless

    Expressive types for Spark.

    Frameless is a nice way to grab some type safety back from Spark, and features opt-in Cats integration.

  • Laminar

    Simple, expressive, and safe UI library for Scala.js (by raquo)

    On the frontend, I use my own Laminar with observables that don't care about purity or tracking effects, and no Cats or Futures or anything else.

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  • Http4s

    A minimal, idiomatic Scala interface for HTTP

    On the backend, I use http4s with Cats Effect, but I don't think in terms of purity or category theory, I just use IO as a nicer Future.

  • ocaps

    Object capability (ocap) tools and macros for Scala.

    I agree absolutely. There are cases where using an effects library is the best thing you can do. I've written an object capabilities library in Scala, and it's a much nicer experience to use capabilities with cats-effect than doing it raw.

  • cats-effect

    The pure asynchronous runtime for Scala

    Akka-stream, zio, and cats-effect all have very simple ways to do this by just passing an Int that specifies the parallelism at the call-site. Akka-stream has mapAsync. ZIO has mapMPar(f:A=%3Ezio.ZIO[R1,E1,B])[R1,E1,B]), foreachPar, etc. Cats has parSequenceN and parTraverseN.

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