I've started learning Clojure about a year ago, couldn't say it was easy (the fault might be with me and not Clojure)
Clojure has a lot a faults (just look at some of the comments here) BUT and it's a BIG BUT for me...
Clojure is SUPER FUN :)
Over the years(15+), I've been coding in PHP (suck it haters), Go, Rust,Java,Python AngularJS+, Svelte and I can honestly say for me, nothing is more fun that coding in Clojure.
It's fun testing a function in "realtime" by just "eval" it on the spot.
I don't even code "in the REPL" I just use Calva and eval inline in VSCode
Maybe it's cause it's my new toy but it really does bring back the "joy of coding" I've been missing in the other languages.
*Learning Clojure became much more easier, once I told myself "It's Maps All The Way Down :D" Sure there are stuff like atoms that make it possible to code around the "immutability" but that is like using a cheat-code to go back to the old ways. Yes there are many times when mutable-data-structures are required, but while learning, don't grab for them as a first solution !
Anywhoo YMMV but once you get over the warts (many there are), much fun and insights awaits :)
Clojure user here since 2010(my earliest Clojure project on Github), and while I agree with the fun point, the iceberg wart for me at this point is the inelegance of the interface hierarchy and its structure behind the scenes.
Clojure's forward-facing interface (a hundred functions that operate on one data structure) ended up breaking down for me at some point and became 10 functions on 10 data structures and those data structures became AFn, APersistentSet, APersistentMap, APersistentVector, IFn, IPersistentSet, IPersistentMap, IPersistentVector, ITransientMap, ITransientVector, IndexedSeq, LazySeq, &c, &c, &c.
Maybe I started writing code wrong. Maybe I dived too deep into the internals, Maybe it was something else. But at the end, there wasn't one data structure, there were dozens and dozens each with justifiable differences, but even so, that's not what was advertised. It took a decade to reach that point and perhaps the vast majority of folks never will.
The sad part is that I know none of it is up for change without creating a Clojure2, and that highlights the problem. Why should changing the internals need to break backwards compatibility? There is one unspeakable reason: the illusion wasn't complete and they weren't really internals to begin with.
I've been programming with Clojure since 2010 and using it in production almost as long and I hardly ever care about the internal types so I'm really curious as to how you went down that "rabbit hole"? What sort of problems were you solving that necessitated delving into the implementation details behind the abstractions?
I've only needed to dig into that occasionally for a handful of specific situations (for example, in next.jdbc, where I create a hash map like abstraction over the (mutable) ResultSet object from Java -- to paper over some nasty interop issues).
Lets say that someone wants to improve on Clojure and make a better functional, immutable LISP! What should they start with ? Some things I miss is type support (for easy refactoring, auto documentation and performance), (small) native compilation, support for mobile platforms and their UI's, first-class web-assembly support, real structs and misc things like performant implementations for `first`, `last` and other clojure functions, light-weight concurrency like Go, data-flow analysis and pipelines, etc.
If you want an easy win, one thing Rich mentioned in a talk is - if he had to do Clojure all over again today - he would put transducers at the 'bottom'. For data transformation this makes the underlying collection type largely immaterial.
> real structs
I'm not even sure if value types are conducive towards immutable, persistent data structures. I'm certainly excited for project Valhalla but I'm not sure if Clojure, nor any Clojure-like JVM language, written in an idiomatic fashion, would really benefit from it.
> light-weight concurrency like Go
Project loom is already in preview mode. Lightweight concurrency is nearly here for any JVM language, and once it's fully released I will likely have zero reason to use core.async.
> type support
Static typing is A Thing you can choose to do, but I doubt you would get many daily Clojure users agreeing that it is "better". I think it's different and better in some circumstances but not necessarily others. It definitely feels trendy these days, sorta like how dynamic typing felt trendy 15 years ago.
Clojure users fighting against static typing are on the wrong side of history. They are fighting a side for all the wrong reasons, and they will lose.
There is a reason why all dynamically typed languages today are scrambling to add some form of static typing to their language, but never the other way around.
I understand the point you're making, and that you wanted to make it dramatically. I got a nice belly laugh thinking about my future grandchildren chastising me for forsaking static types:
"All your life's work for naught, Pepaw. If only you had been on the right side of history".
I do have a substantive disagreement with this statement: "There is a reason why all dynamically typed languages today are scrambling to add some form of static typing to their language, but never the other way around".
Languages like C#, Java, Scala, and Typescript have all adopted some degree of type inference. Their users wanted it for a long time. To begin with, none of these languages are anywhere near as strictly-typed as a language like Haskell. Clearly even developers on "the right side of history" don't want to maximize static type checking in all cases, so the issue is not as cut and dry as you make it sound.
Yeah and spec isn’t trying to press the real world into arbitrary categories? /s
The thing is, having some structure in terms of types or data shape constraints helps you model and understand your program. You can change them as your understand of your program changes or the need arises. You can be against static types because they force you to slow down and think about things before you can just get to coding, and it can be sometimes annoying to model your system using them (and sometimes not so useful), or other technical reasons like some type systems don’t allow you to model certain things, but to say it just leads to devs putting the real world into stupid, arbitrary categories when the real world (and your program!) primarily have data that can be trivially categorized because that’s what Rich Hickey said makes you sound like cargo-culting or parroting a point without diving deeper into the specific reasons and potential counterarguments.
However, to be fair, Clojure's response to types is `org.clojure/spec.alpha`, and if you give it a really good chance, you'll see that it brings a lot to the table.
It doesn't change that I believe strong typing (a Haskell or Idris/Agda-like flavour of it) to be the future, but what it did change was how I thought about type systems and how to write and test programs.
Yes on the type support not really attracting Clojure users. If you wanted to enable better refactoring, the thing to do would be to take more pages from other lisps and use the compiler to add more metadata to the runtime (in development mode at least) so that you can get better tracking of the language constructs.
I appreciate that it's a bit frustrating to have someone vaguely identify an area of concern and clarification and actionable suggestions are much more valuable.
There's two things. One is that the data structure ontology[1] is difficult to internalize because of its complexity. When I write Clojure code, I consider the capabilities of the data structures being passed to the function. I think we have some implicit understanding of this early on. You expect the type of such and such to support seq-ing or deref-ing or something else. You're thinking in terms of capabilities and that's good. But if you want to be exacting, at some point you'll have to be able to point to an interface or several in the diagram and say, "yes, I really do expect something that conforms to IPersistentVector or IMeta or something else. In order to preserve backwards compatibility, this is more confusing than it needs to be. Moreover, at that point, you're not in Clojure-land anymore.
My second point is that at this step in the narrative, you're reading Java code and the illusion of 100 functions is broken. I ask myself, "Why, aren't Clojure data structures implemented in terms of protocols?" There's a perfectly good way of abstracting functionality that seems good enough for users, but not good enough for standard library implementers? It feels like the answer is, "We don't want to break Clojure1.x and we don't want to deal with the Python3 problem." Which is fair, admirable even, but it still leaves me left wanting. I think there's a simpler, more consistent Clojure hiding in there, waiting to be let out.
Apologies for the awkward way this reads; I simply wanted to get it out before lunch time.
I don't want this to sound hostile because I have a similar love/hate relationship to Clojure, I truly don't understand what you're arguing. Or, it seems like your issue is with lack of static types rather than an issue with the implementation? I've written a lot of Clojure and have an okay to pretty good understanding of the implementation, but it's just hardly ever relevant to the code I write, so I still don't totally understand what you're getting at exactly. Like, what's the actual problem here? Just that there's more Java "intrinsics" than pure Clojure code? I guess I do agree that Clojure is really just Java, and it would do better for people to think about it just as (really nice) syntax sugar over Java, but I guess I don't see that as a problem, but rather the absolute biggest strength of Clojrue.
I think he is arguing for more protocols than simply sequence. That is a sequence can be attributed fine-granular capabilities represented by protocols and that allows generic functions to be tailored towards those capabilities for improved performance.
Are you really suggesting type support? I don't mind types but I think spec is more in the spirit of Clojure. Have you taken a look at it? https://clojure.org/about/spec
spec is mostly useless for tools and IDE's and static analysis. Spec necessitates running your program with an arbitrary runtime complexity. Type checking is done before your program runs. The idea is to remove the need for runtime checks as much as possible.
But clojure is not meant to be developed statically!
It is supposed to be running while developing it. You don't need static analysis if the programm is running and inspectable.
Right ! But you still had fun the last decade correct /s ? :P
My "real response" to is, I haven't seen this complaint(concern) to this extend that you describe in the wild or in my own life. I've definitely not coded in Clojure long enough to have seen any of that like you have, thus far my experience has been good with 'just' using maps.
I do feel my next "step-up" would be to incorporate something like SPEC or Mali to "define/check" the fields/structure of said maps.
An interesting complaint. What problem domain(s) do you work in? It sounds like you've found something that Clojure isn't a great fit for.
The mix of interfaces would be a huge pain if you needed their specific behaviours, but in my experience they've never mattered and lings like LazySeq just act as performance optimisations.
Do you have some os projects out there to share where you had to do that? Makes me curious, I think the only time I've ended up making a specific data structure in clojure was for a library for perf reasons. In application code basically never.
Specifically it was using GraalVM to interop Clojure on one side with React running on GraalJS on the other. It definitely pushed the limits of what is or even ought to be possible, but at the same time highlighted those very issues. I'll be the first to admit that this is an extreme edge case, but that doesn't take away from the fact that the case is still there.
Same here, started using Clojure pretty much exclusively about a year ago and never looked back. It was rough to get to that comfortable state where I am now, having to find out how Clojure CLI tools work, what Java Classpaths are, how to properly set up my editor (Neovim), how to make sense of Clojure internals like “seq” and when to use which collection type (and when not to care), etc.
But it has also been a fun and liberating experience, after I went down the static type route for some years. I feel like Clojure just doesn’t get in my way and doesn’t force me to follow a certain style or paradigm; it provides many different choices (“providing more” instead of “taking away”) and treats you like an adult who can make responsible decisions on their own.
Although I missed the linguistic art of domain modelling through type definitions, spec gave me some of that back and even provides stuff like generative testing, which is pretty awesome. Of course, it is not meant as a replacement for static typing and has a different philosophy (see Rich Hickeys talks about it), but for me it is the best of both worlds.
The dynamic development style is something that I experienced before through learning Lisp/Scheme and it is also one of the thing that I enjoy most about Clojure. Coding “experimental”, building functions from individual pieces that I iteratively design using the REPL as my assistant (which actually means - as parent wrote - communicating with it from the editor itself, which we mostly do), feels so natural and I would miss it now that I am so used to it.
> treats you like an adult who can make responsible decisions on their own
I have to disagree with this characterization. It also seems a bit patronizing.
Having more choice can be good in some cases, and having fewer choices can be good in other cases. One isn't treating you less like an adult than the other.
> doesn’t force me to follow a certain style or paradigm; it provides many different choices (“providing more” instead of “taking away”) and treats you like an adult who can make responsible decisions on their own.
This is really not correct. Certain choices Hickey made, prevent you from coding as you like. E.g., Hickey doesn't allow strong reader macros or inheritance in Clojure.
Stage5: All other languages and their syntax now looks ugly and wrong. I'm mean for heavens sake put the parens on the outside ! We are not heathens.
Lol only half joking. It really did surprise me how can something I hated some much in the beginning of learning Clojure (all the parens) has now become one of the things I most adore about the language (all the parens)
It's really hard for me to see any justifications for a syntax that's not based around s-expressions. The benefits of being able to trivially transform any code as data and have powerful structural editing facilities outweigh any perceived downsides in my experience. I also find that s-exps act as a visual diagramming tool making your code more scannable because you can visually see the relationships between statements by looking at the nesting.
> I also find that s-exps act as a visual diagramming tool making your code more scannable because you can visually see the relationships between statements by looking at the nesting.
I think this is where people disagree regarding syntax. I love Clojure and agree with all the benefits of s-exps, but find it basically impossible to scan and very tedious to read. While it tends to be easy to refactor do to the REPL, at least for me it's on the wrong side of readability vs expressivity.
When I look at Clojure code, it just looks like noise, all the forms look the same. For example, a let and a doseq at first glance might look almost identical in terms of their "shape." In something like Java, a for-loop "looks" like a for-loop, there's nothing else in the language that looks quite like it. If I see a series of chained lambdas, there's an extremely high chance I'm looking at a stream, etc. The syntax helps me here by adding more obvious visual markers.
The argument I'd make in favor of Clojure and s-epxs is that, when you write good functional code that composes lots of small functions, it can literally read just like English. If foo and bar do baz else qux. But bad Clojure code doesn't have this property to me, it just looks like a lot of noise.
Stupid question, but do you have something like "rainbow-brackets" active in youre code-editor ? I found it really help me.
The more I read LISP/Clojure code the easier it becomes.
I agree that it's possible to write dense code that's hard to read with Clojure, but that is true in any language. I've seen plenty of Java codebases that I couldn't make heads or tails of. As you point out, well written Clojure often reads like plain English. So, in my view it's just a matter of making the effort to write readable code on the part of the developer.
I've been working with Clojure for the past decade, and it's still the most enjoyable development experience I've had. Once you experience using an interactive workflow where you can see the results from the code you're writing live, it's really hard to go back.
I physically suffer when I go back to systems like django, where there's no principled underpinnings, no 'protocol' and only a thin way to interact with the system live.
Can you recommend a good YouTube video that demonstrates this? I'm used to writing code incrementally in Python via the IPython REPL. I've also used Twisted's Manhole to get a REPL inside an already-running Python server process. But I believe you're referring to something substantially richer than that.
For me, it's a combination of having a REPL and having a good interactive interface between the editor and the REPL. Typing forms into and evaluating them in the REPL is one thing, but typing them into your editor file and evaluating them from there in the REPL is much more useful. (I can't fairly say one way or the other whether that's possible/common in IPython.)
There's a lot of idiosyncratic advice in those Halloway talks, and people shouldn't blindly adopt it wholesale without evaluating if it's right for them.
Learning to evaluate forms directly from the editor is great, but _never_ typing in the REPL forces you to clutter up a file with evaluations you may not want to save, and jump around a lot between your comment blocks and code.
You can do interactive development in Python using emacs and the “elpy” package. I’ve only used it for small scripts, so I can’t say how it compare to Lisps.
it's easy to run a lisp (clisp on linux) or scheme (guile on linux) REPL and then paste in example code and see what it does, there's lots of examples out there. Then I'd say try playing with "call with current continuation" if you want to see mind-bending elegance (or let's say it's an elegant implementation of something you'll never be sure you understand)
Clojure has a lot a faults (just look at some of the comments here) BUT and it's a BIG BUT for me...
Clojure is SUPER FUN :)
Over the years(15+), I've been coding in PHP (suck it haters), Go, Rust,Java,Python AngularJS+, Svelte and I can honestly say for me, nothing is more fun that coding in Clojure.
It's fun testing a function in "realtime" by just "eval" it on the spot. I don't even code "in the REPL" I just use Calva and eval inline in VSCode
Maybe it's cause it's my new toy but it really does bring back the "joy of coding" I've been missing in the other languages.
*Learning Clojure became much more easier, once I told myself "It's Maps All The Way Down :D" Sure there are stuff like atoms that make it possible to code around the "immutability" but that is like using a cheat-code to go back to the old ways. Yes there are many times when mutable-data-structures are required, but while learning, don't grab for them as a first solution !
Anywhoo YMMV but once you get over the warts (many there are), much fun and insights awaits :)