4ever-clojure VS schema

I found this to be an awesome bridge between reading about the theory and actually writing code that works: https://4clojure.oxal.org/

This is for general Clojure, I’ve had a lot of fun and learned a lot from it (and the original): https://4clojure.oxal.org/

It's normal to apply methodology like this to clojure when transitioning from other languages. When I was first learning I did a bunch of exercises on 4clojure and my first attempts looked like this. Then I found loop from the standard library and I understood immutability but relied on loop to do anything to collections of things. Eventually, after looking at the answers, I started to get familiar with the standard library. Then my solutions started to look like the two line solution above.

4Clojure is here now: https://4clojure.oxal.org/. It runs locally in your browser.

Go to https://4clojure.oxal.org/ and solve some stuff. And don't learn any theory. You're thinking how a C# developer thinks and you think you need to learn some kind of packages by heart or something.

I learned by reading through a book, then working through problems on https://4clojure.oxal.org/. If you've got JS experience it won't take too much effort to pick up. Don't get too carried away with forming the perfect tail recursive pure functional monad or whatever. Get into just doing what you're trying to do quickly, then after you're competent, read other people's code to correct your style.

I'm only a couple months into learning Clojure too, but I found solving a problem myself and then seeing others solutions on this website https://4clojure.oxal.org/ was invaluable for learning to think like a clojurist.

I'm trying to learn Haskell and found https://4clojure.oxal.org/ very helpful. https://tryhaskell.org/ was also nice, but it is limited in scope as compared to its Clojure equivalent.

The actual address is https://4clojure.oxal.org/

Plumatic schema (https://github.com/plumatic/schema) , or friends I might be wrong, but I think schema might make more sense to you coming from the F# world (might be wrong)

This one? I didn't. I hear good things about it, and it's reached a point of maturity, being widely used in production.

Uhhh spec has existed for a long time and before that, schema Nowadays we also have the excellent malli. If his codebase is full of functions where the shape of the data isn’t obvious, isn’t documented and isn’t specified in a specific/schema, that’s on him and his bad coding practices and really no different from passing data in other dynamic languages. A class by itself (without additional effort) only gives you field names.

I don't understand this reputation either. There are very large systems built on other Lisps. For example, Emacs has a massive amount of Elisp. Elisp is much more primitive than Clojure, and traditionally libraries don't use e.g. data schemas [1] as runtime contracts for data.

Obviously, once a system built on top of a dynamic language grows beyond certain threshold, you need to be very disciplined as there are no static types to ensure some degree of correctness.

[1] https://github.com/plumatic/schema

Try to learn a schema library early, like Malli or Prismatic Schema. Do not mistook them as "static-typing" things - it's more for data validation and coercion than "security that things will get the right typing information". The idea to learn them early is how you'll shape future code: validating all "output data" first, them using that data inside your program without "defensive programming" like checking every time if a specific value on a map is nil, etc

In Clojure, declarative data specifications for validation and generation are also very mainstream. Schema was first out the door, Clojure Spec is the most popular library, while malli is gaining popularity fast at the moment.