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Racket v9.0

blog.racket-lang.org

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Re: Racket v9.0

#81

Post by bmitc »

jetti wrote: post #79
kryptiskt wrote: post #26

The big news here is that Racket now can run threads in parallel. While there were ways to get parallelism before (like places), this is much more lightweight and familiar. Anything that expands the areas where Racket is viable is good news to me since I like writing stuff in Racket.

What kinds of things do you write in Racket? I’m a clojure dev and so I’m a big fan of lisp. I’m just curious what kinds of projects you would use Racket for

I'd say anything you use Clojure for except for Clojurescript.

Re: Racket v9.0

#82

Post by mark_l_watson »

I love Racket. Just for fun, I wrote a Racket book, read online: https://leanpub.com/racket-ai/read

For Scheme languages I recommend Racket or Gerbil. Racket is great for beginners since the IDE is pretty good and the standard libraries and contributed libraries are good. Gerbil is good for systems programming. network utilities, etc.

Re: Racket v9.0

#83

Post by bmitc »

ModernMech wrote: post #57
nesarkvechnep wrote: post #55

Earlier quoted context omitted.

How rewriting something internally makes Racket not mature? Sounds like refactoring to me and with an extensive test suite there's nothing to be hysterical about.

Maybe I just have a different working definition of these words. To me "mature" means "fully developed" and "polished" means "achieved a high level of refinement". To me, rewriting it all to introduce a major feature that fills in a longstanding hole in the language doesn't say "mature and polished". Because often times many bugs are introduced into a codebase on a major rewrite despite extensive test suites, especia…

I think you should read the old posts as to why Racket transitioned it's guts from primarily C to Chez Scheme. It would save a lot of time in the discussion here if you became familiar with that transition.

The short story is the same as anything written in C: it's an unwieldy language.

Re: Racket v9.0

#84

Post by nothrabannosir »

ModernMech wrote: post #53
spdegabrielle wrote: post #43

Earlier quoted context omitted.

This is addressed in the blog post linked from the release announcement: https://blog.racket-lang.org/2025/11/parallel-threads.html

That post is even more worrisome! > To address larger problems with the implementation and to improve performance, we started in 2017 rebuilding Racket on top of Chez Scheme. Rebuilding took some time, and we only gradually deprecated the old “BC” implementation in favor of the new “CS” implementation, but the transition is now complete. Racket BC is still maintained, but as of August 2025, we distribute only Racket…

They might be making a distinction between the language and the current implementation. In fact I would call going through multiple different fundamental implementations without changing the semantics, an argument in favor of the maturity of the language.

Re: Racket v9.0

#85

Post by igouy »

gus_massa wrote: post #71
brabel wrote: post #68

Earlier quoted context omitted.

I liked it many years ago but when I noticed how slow and heavy my code was I left it. It manages to be slower than Python. Perhaps the Chez Scheme rewrite helped with that but now if I need a Lisp I have Common Lisp which is super fast and lightweight enough.

It's usually faster than Python for numeric stuff, and has a similar speed for strings. See for example https://benchmarksgame-team.pages.debian.net/benchmarksgame/... But if you run the code inside the default IDE call DrRacket, you must go to the menu Language>Choose_Language... then click "Show_Details" and disable "Debugging". With debugging enabled, you get nicer error messages, but it blocks a lot of optimizati…

See for example

https://benchmarksgame-team.pages.debian.net/benchmarksgame/...

Re: Racket v9.0

#86

Post by skanaley »

epolanski wrote: post #8
varun_ch wrote: post #3

Racket is a fun language. My university uses the bundled teaching languages for first year CS courses. Some people really hate it, and others silently like it.

And all of them agrees to never use it after university, which is quite telling.

I use it professionally. My favorite is its seemingly complete lack of bad behavior:

"3" + 1 is neither "4", "31", nor 4. It's illegal.

0 is not false, causing endless confusion on filters and &&s.

For loops don't alter the iterated value within a closure to the max value when it's finally called.

And some positives:

Immutable/functional is the default, but mutability is easy too.

Nice optional, keyword, and variable arity support.

Straight forward multithreading, semaphores, shared state, and unshared state.

Excellent module system:

- renames both in and out, including prefixes, all applied to arbitrary scopes of identifiers (I may be using inaccurate terminology)

- nested submodules

- automatic tests and/or "main" submodules

.....etc.......

If I could be grated a wish though it would be for nice struct syntax, but I think that's in Racket's successor Rhombus; haven't personally tried it yet.

I also sometimes wish it was slightly Haskell-ier in various ways, as did the talented individual who created Hackett.

If I were to guess why it's not used, it's because it's not used, which has a kind of downward-spiral force thing going on with it. If you're a random guy in charge of 200 dudes at BigCo, your first thought probably isn't "We should rewrite this whole thing in Racket!", it's probably more like "We should fire everyone and have Claude rewrite our codebase into Rust!" and tell your boss you saved 200*0.5M a year and ask for a comparative bonus. But if you're solo and in charge of designing, implementing, and maintaining a system with 1 or 2 people over the next 20 years, you can use whatever language you want, and Racket's a pretty good choice.

Re: Racket v9.0

#87

Post by zelphirkalt »

epolanski wrote: post #8
varun_ch wrote: post #3

Racket is a fun language. My university uses the bundled teaching languages for first year CS courses. Some people really hate it, and others silently like it.

And all of them agrees to never use it after university, which is quite telling.

Sometimes it takes a couple of years, before a seed grows. I for one had a professor, who said: "I am not here to teach you C or Java. I am here to teach you computer programming." and then went on to take us on a tour through various paradigms, and included Prolog, back then Dr.Scheme (which turned into Racket), C, Java and Python. At the time I didn't understand Scheme at all. Didn't understand the idea of passing a function as an argument, so deeply rooted in the imperative world I was. But a couple of years later, I came upon HN and comments mentioning SICP ... Didn't that professor teach us something about that? What if I took a look and started learning from this book everyone is recommending?

And there it was. I worked on exercises of SICP and finished approximately 40% of the book's exercises and had a very solid grasp of Scheme and Racket, and any hobby project I would take out Racket to try and build it. Along the way I learned many things, that I would still not know today, had I stuck with only mainstream imperative languages. I wouldn't be half the computer programmer, that I am today, without going the SICP and Scheme way. I also worked through The Little Schemer. What an impressive little book it is!

So it is far from what you claim. In fact even a little exposure to Scheme once upon a time can make all the difference.

Re: Racket v9.0

#89

Post by wduquette »

zem wrote: post #58
wduquette wrote: post #30

I first experimented with Lisp back in the mid-80’s, and have returned to it time and again—not as a language for serious projects, but just as a way of learning new techniques and new ways to think about writing software. I’ve tried using Racket on a number of occasions going back to way before it was called that, and something about the software just puts me off. Perhaps I could get past that if I stuck with it, bu…

when you say "software" do you mean the language features or the tooling?

The tooling.

Re: Racket v9.0

#90

Post by zelphirkalt »

linguae wrote: post #23
dleary wrote: post #16

Earlier quoted context omitted.

Everyone gets to choose which language they use for their personal projects. Where are all the Racket personal projects? N.B. I say this as someone who personally contributed small fixes to Racket in the 90s (when it was called mzscheme) and 00s (when it was called PLT-Scheme).

I view Racket as an academic language used as a vehicle for education and for research. I think Racket does fine in its niche, but Racket has a lot of compelling competitors, especially for researchers and professional software engineers. Those who want a smaller Scheme can choose between plenty of implementations, and those who want a larger language can choose Common Lisp. For those who don't mind syntax different…

I wish Standard ML had a strong ecosystem and things like a good dependency manager/package manager. I really liked it. But there is even less of an ecosystem around it than some other niche languages, and I've gone into the rabbit hole of writing everything myself too often, to know that at some point I will either hit the limit of my energy burning out, or the limits of my mathematical understanding to implement something. For example how to make a normal distribution from only having uniform distribution in the standard library. So many approaches to have an approximation, but to really understand them, you need to understand a lot of math.

Anyway, I like the language. Felt great writing a few Advent of Code puzzles in SMLNJ.

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