Same can be said about Clojure. Although Clojure usually described as an FP-language, it's not "purely FP". In general, I find that Lispers typically don't concern themselves with the popularity of certain tools or techniques; They don't care for things like MSFT marketing shoveled in your mouth. Die-hard pragmatists, they'd use an instrument if it makes sense. They don't give two shits about OOP propaganda or extreme functional purity, or the notion such as "not using static types is immoral" and shit like that, they'd use object-orientation where it makes sense; metaprogramming, where desired; constrains, if applicable; concurrency when required, etc. All that without any zealotry - just pragmatic use of the right tools for the job, embracing Clojure's flexibility and power while staying true to the only core "philosophy" - "simple made easy".
As a dyed-in-the-wool Clojurist, I appreciate leveraging the functional aspects as much as immutable by default data structures. It takes a while to stand back and realize, but once you have a large program that is mostly all passing immutable hashmaps all around to static functions, testing becomes soo much easier and reasoning about how all the code is glued together becomes far easier. You know with certainty that code doesn't have all the ordering problems that come with Objects, whether you called some random function on some object at aome time that cached some instance variable that should have been shared with some other object. Reasoning about that is nuts, and the status quo for most OO code I've seen. If you know that most code only is implemented with pure functions with immutable data, then the ordering questions are nearly completely gone. You can now refactor so much easier as well without risk of subtle ordering related breakage. And then Clojure has atoms and channels which are very nice, thread-safe constructs that also are far easier to know your code won't have memory safety issues. I have dabbled at learning Rust or Haskell or Swift but Clojure gets so much so right.
I know, right? It may feel weird at first - with immutability, parentheses and prefix notation, but once you grok REPL-driven interactivity and structural editing - so much about programming becomes intuitively simpler.
I have the same experience. I learned Haskell because of the aura of prestige around it, and must admit I still love the syntax, but moved over to Clojure as my daily-driver as the practicality of "just use maps" is incredible.
IMO the article misses the point there. Immutability is the "thing" in FP.
Yes! I spent months (maybe even years) trying to understand Haskell, and for the love of god, I just couldn't wrap my head around so many things. I just wanted to build stuff with it, but it felt like becoming a doctor - getting a bachelor's, passing MCAT, then four years in medical school, then residency program, then getting a license and a board certification. All that for the sake of knowing how to properly apply a band-aid (or something). Except, with Haskell, there's no rigid structure, there's no single, proven, 100% guaranteed path to glory - it's all blur. There's no "10 steps to build a website with Haskell". And then I picked up Clojure, and OMG! everything suddenly started making so... much... sense... All the things in Haskell, for which I had either no clue or had some shallow understanding - that all became so much more intuitive.
It definitely took me at least 3 years of reading and practicing to be able to get to -at least think- understand it, and I still think I would be considered pretty incompetent by people that do Haskell daily.
There is no doubt in my mind that the Purity concept in Haskell is taken to an impractical degree. I happen to like it, but it does not make developing software with it any less of a troubled experience. The defining concept in comparing Haskell and Clojure for me is the pareto principle :D Clojure gets 80+% of the way there, without 80% of the self flagellation.
There is also a consideration of static typing vs dynamic but that's a whole other can of worms.
Simply, in Haskell all mutability is delegated to the runtime while in clojure one has the freedom and responsibility to manage it directly, and boy does it gain in simplicity for it!
I know I am preaching to the choir but it's pleasant to find a similar experience and share thoughts!
