In short, jank is Clojure, but it's on LLVM and has seamless C++ interop. You still get full nREPL capabilities, can redefine anything on the fly, and we can actually JIT compile C++ code alongside your Clojure. The seamless C++ interop is first of its kind, for a lisp, and is done by JIT compiling C++ alongside the LLVM IR we generate for jank and then stitching them together into one IR module.
Note, jank isn't released yet. I'm targeting the end of this year for the first alpha release. I put out monthly development updates on the jank blog, with the next one coming out this week.
however my only gripe with clojure while it's easy to write and comprehend at first - it's difficult to read. & yet most our time we read code not write it. but then again it might be my lack of brain power.
Also writing Clojure can be incredibly terse, resulting in quite high-effort when reading. Conversely, a lot of time I can condense hundreds of lines of equivalent python into 5 or 6 lines of Clojure. Having all of this functionality condensed into something you can fit in a tweet really helps for grokking larger parts of the dataflow or even larger system. So there are tradeoffs
Plus structural editing and the repl really help with the “reading” experience (reading in quotes because it’s much more interactive than reading)
I'm curious if you have any example of this? Even if it's an hyperbole, I don't really see how.
1. You’re mapping or reducing some dataset
2. Your iteration logic does not branch a lot
3. You can express your transformation logic using higher order functions (e.g. mapping a reduction operation across a multidimensional array)
Some domains have a log of this style of work—finance comes to mind—others do not. I suspect this is why I’ve personally seen a lot more of Clojure in finance circles than I have in other industries.
Once Clojure parity is achieved, I'm interested in static typing, pattern matching, value-based errors, and some other opt-in improvements that I think will greatly improve both readability and toolability (i.e. how well tooling can work with the code, based on what it knows of the code). Stay tuned. :)
For a practical example of a Clojure-like language with a completely static type system (with affine typing), see Carp. https://github.com/carp-lang/Carp
I don't see why there can't be a Carp mode in jank, with bridges in place to connect the Clojurey world from the Carpy world. This would allow jank users to develop interactively to start with, figure out their shapes, use the REPL, etc. Then, if they want, they can lock down some parts of the code for both performance and correctness gains.
Do you plan to make Windows support first-class? I think a lot of people looking at LLVM based languages are interested in alternatives to C++ for games.
jank is Clojure. However, the Clojure name is trademarked and using it requires permission which I don't have. Furthermore, I want to build upon the Clojure base to provide more, going forward. That may include static typing, value-based error handling, first class pattern matching, and so on. Those would be opt-in features on top of Clojure. All of these reasons lead me to not use Clojure in the name (like Clojure++, ClojureNative, etc).
> Do you plan to make Windows support first-class? I think a lot of people looking at LLVM based languages are interested in alternatives to C++ for games.
Indeed, a lot of game dev folks use Windows. Right now, jank's Windows support is limited. My initial audience is Clojure devs who want native access and lighter binaries. Once that launch has stabilized, I will focus on appealing to existing native devs who want to embed an interactive, functional language into their C++ applications. That will requires strengthening the Windows support, establishing stable native APIs, and writing the onboarding material for lisp, REPL-based editing, data-driven design, and so on. This is a much larger task, which is why I'm focusing on existing Clojure devs first.
But for the love of... please pick a different name.
Whatever reasons companies/teams will have for not letting someone use Jank at work, don't let the name be one of them.
I love this project, and frankly I can't wait until I see Zig code stitched into and interoperating in a lisp via C transpilation, but I really do agree with the top commenter if you can't get Clojure trademark approval.
Anyways, keep up the amazing work, I wish I could have seen your janky talk at Strangeloop on another timeline.
https://jank-lang.org/blog/2025-04-01-jank-has-been-renamed/
This allows jank to offer the same benefits of REPL-based development while being able to seamlessly reach into the native world and compete seriously with JVM's performance.
Performance measurement and optimization is something I thoroughly enjoy and look forward to being able to focus on once jank hits parity with Clojure and is stable enough to warrant performance as a priority.
Edited: Here is a post in HN from 2014 about Clapp. https://news.ycombinator.com/item?id=8367404
In that post and comments we read that Clapp was 100x slower that sbcl, and the author of Clapp claimed: "LLVM is a great library for implementing C and C++ but more work needs to be done to support Lisp features like closures and first-class functions. We are working on that now".
I hope Clapp's author work in the last 11 years could help today efforts. Surely, the LLVM of today is not that of 11 years ago. Anyway, IMHO, sharing some knowledge could be productive for any project that is about C++, Lisp or Clojure using LLVM.
If I recall correctly, compiling Clapp takes a full day, that gives not a good vibe.
On the happy path, I think that Julia transpile to LLVM, but Julia is the result of many men working years at it. Honestly, I don't think that one single programmer to be able to create such a big project as a performant clojure in C++ will the ability to compile code quickly. Getting sbcl speed and compilation speed would be an extraordinary feat!
In Go there were great sacrifices to get fast compilation, and the problems to include generics, trying to avoid blows up compilation because some type checking is NP-complete.
Also perhaps ECL, a lisp in C, can gives us some hints about how to get better performance and compilation speed.
Perhaps I am just too old to be open to new dreams, anyway I hope the best to this project and I thank to Clojurists Together for supporting this project. It must be very intellectual rewarding to work in a project whose aim is to extend and improve your favorite computer language. But the journey will be no an easy one, that's for sure.
I'm aware of Clasp and have spoken with drmeister about it in the early days of jank. Ultimately, jank and Clasp differ greatly, not only in that jank is Clojure and Clasp is Common Lisp, but also in their approach to C++ interop.
> If I recall correctly, compiling Clapp takes a full day, that gives not a good vibe.
I'm not sure about Clasp's compile times, but C++ is slow to compile, in general. The jank compiler itself builds from nothing in about 1 minute on my machine. We've yet to see how the jank compiler will handle large Clojure project, but I do expect it to be slower than Clojure JVM.
> In that post and comments we read that Clapp was 100x slower that sbcl
That's an old post, so I'd expect that Clasp is faster now. I can say that jank is not 100x slower than Clojure JVM, in my benchmarks.
> Perhaps I am just too old to be open to new dreams, anyway I hope the best to this project and I thank to Clojurists Together for supporting this project. It must be very intellectual rewarding to work in a project whose aim is to extend and improve your favorite computer language. But the journey will be no an easy one, that's for sure.
Thanks for the interest and kind words. It's not easy, but it's doable!
Are there Clojure libraries that don't use JVM(/JS/...)-specific stuff that works on any Clojure platform/dialect? Can such libraries be used on Jank out of the box? Or do library authors have to do something explicit in their libraries to enable their use in specific platforms/dialects?
Correct. Any Clojure code which doesn't use interop will generally work with Clojure, ClojureScript, Clojure CLR, jank, etc. There are some exceptions, where different dialects don't fully implement a Clojure feature, but this is generally the case.
> Or do library authors have to do something explicit in their libraries to enable their use in specific platforms/dialects?
Clojure also supports reader macros to enable forms for specific dialects. This is basically like an #ifdef in the C world, where library devs can check if the code is currently being compiled for Clojure, ClojureScript, jank, and so on. This allows you to have a public function, for example, which internally just uses a reader conditional to do the correct thing. For example:
(defn sleep [ms]
#?(:clj (Thread/sleep ms)
:jank (let [s (/ ms 1000)
ns (* (mod ms 1000) 1000000)
t (cpp/timespec. (cpp/long. s) (cpp/long. ns))]
(cpp/nanosleep (cpp/& t) cpp/nullptr))))
Parens don't matter, but giving values names causing indentation is something I simply cannot abide as a terminal intermediary value name giving person.
EDIT: oh and also something with "proper" multiline comments. Thanks!
If you're interested in funding this work, or helping with the designs, please reach out. In the meantime, make sure you check out Rhombus. https://rhombus-lang.org/
The link to Rhombus is very interested, I hadn't heard of this and it looks very well developed. Will mess around with it.
https://yamlscript.org/about/ - YAMLScript (or YS) A graal pre-compiled Clojure environment, like Babashka, but uses a different, looser syntax (yaml based). Can run from command line.
Like a nicer Python?
axblount•5h ago
Jeaye•5h ago