Chimney VS cats

But yeah, I wonder if using a tool for case classes conversion like https://github.com/scalalandio/chimney would help in managing those ADT hierarchies for DB/business logic/web layer/etc.

Hello, if you have some nice examples could you please check if it's something that would fit any of issues planned for 0.7.1 or create a new one?

Perhaps, https://github.com/scalalandio/chimney would leverage it.

Thankfully, there are some solutions that can help reduce the boilerplate of these manual conversions. For instance, chimney : https://scalalandio.github.io/chimney/

I want to upgrade one project to Scala 3.1, but I'm using the macro heavy chimney (https://github.com/scalalandio/chimney) to reduce the boilerplate, which is not available for Scala 3 yet. My idea was to copy and paste the code that chimney generates on 2.13, and after that uncomment the uses of chimney for now.

In my $dayjob we originally used Scala, but I pushed for a couple of new services to be written in TypeScript/Node as it was really hard to hire Scala developers. I'd say it worked well, we even took a somewhat functional approach to building things. We tried fp-ts but that was a bit hardcore (when you are trying to hire TypeScript developers who don't know functional programming), so just built Either and Option types which provided 99% of what we needed.

There are still a few things I miss though:

* Pattern matching and exhaustive checking. Using a switch statement it is possible to define a function that can emulate the compile-time exhaustive checking, but it's still rather weak compared to what you can do in Scala.

* Implicits. Being able to define something that can convert say a UUID to a String or vice versa automatically just feels like magic, especially when dealing with data from third party systems.

* Compiler macros and metaprogramming. It enables tools like Chimney (https://scalalandio.github.io/chimney/) to be built, which I don't think are possible with TypeScript right now.

Converting between these classes can add some boilerplate, but luckily there are libraries like https://github.com/scalalandio/chimney that make it much easier.

A functional programming library: https://typelevel.org/cats/

Learn something that pays the bill first - nowadays it's Golang/Rust react/typescript. Then you can try some pure fp libs like fp-ts and fp-core.rs, and look through existing scala cats docs. If you'll feel bad about it - that's totally fine and expectable, fp takes a paradigm shift and not that many dev able to shift their brains way of thought due to basic psychological rigidity) (inability to change habits and to modify concepts/attitudes once developed). And that's purely a staffing and management issue - folks hired randoms out of the blue, and called 'em a team.

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.

As a former functional programmer in Scala, please do not go deep into the Category Theory programming. Scala has libraries like this one called "Cats", a cute shortened name for "Category Theory", but code that makes heavy use of these constructs is not understandable to other programmers. Other than using Monads as a design pattern for things like Options (which can be "Some" or "None"), Futures or Promises (which is used for asynchronous programming), and a few other things, please do not make heavy use of category theory constructs in real programming projects that will have other developers working on them. It is a rabbit hole that may be fun but is not super practical. Sure, write pure functions without side effects, but do not use the words "Bimonad", "Invariant Monoidal", and "Semigroup" in your code. The most common, practical application/use of functional programming is basic things like closures, .map, .filter, maybe chaining maps with like a .flatmap or whatever your programming language uses instead of chain or flatmap, and SQL that uses keywords like WHERE which can be represented in code by using a call to .filter. Like the place where these constructs are used most is in data processing like with SQL, ETL (Extract Transform, Load) jobs, Java's MapReduce on Hadoop, Scala's Apache Spark, and other data processing type things. Haskell is not a popular programming language in real world projects for a number of reasons and one of them is the heavy and sometimes impractical use of Category Theory.

At a previous job of mine we actually had an entirely pure Scala ecosystem using cats which instead uses typeclasses, referential transparency, and other FP concepts as the foundations for how to code. So a lot of flexibility to the language.

Thanks! It's used heavily here

I did work in Scala for a few years. We employed Cats[1], and even a bit of Matryoshka[2] though most of the work I do today is in Python.

Nowadays I think about computational requirements in terms of relations among behavioral dependencies. Like, "I want to perform operation O on input A and return a B. To do this, I'll need a way to a -> b and a way to b -> b -> b." I often pass these behavioral dependencies in as arguments and it tends to make the inner core of my programs pretty abstract and built up as layers of specificity.

Zooming out nearly all the way, it makes me feel tethered in a qualitatively unique way to certain deep truths of the universe. In a Platonic sense, invoking certain ideas like a monad make me feel like I'm approaching the divine or at least one instantiation of a timeless universal that operates outside of material existence.

I'd imagine some mathematicians might see the universe in a similar way - one where immortal relations between ontological forms exist beyond time and space and at the same time can be threaded through the material world by intellectual observation and when those two meet a beautiful collision occurs.

1. https://typelevel.org/cats/

2. https://github.com/precog/matryoshka

Our second type class example attempted to illustrate one last perk: type safety at compile time. It did so with a simplified example of the cats core library for type safety equality comparison between objects. If you're not familiar with cats, go ahead and give it go.