5 ms·

From Rust to Ruby

127 points by xlii 5mo ago

lmm 5mo ago
"I have no idea if it works or not because I haven’t yet tried running it. But it's 5x shorter!"
- october8140 5mo ago
  The fact that it doesn't end with what happens when they run `rails server` makes me think they did it and didn't like the results.
- pahbloo 5mo ago
  Not a xkcd, but quite relevant: https://web.archive.org/web/20091015091833/http://www.hackles.org/cgi-bin/archives.pl?request=310 https://web.archive.org/web/20091015091833/http://www.hackle...
daemin 5mo ago
At first I thought this would be an interesting article, but as soon as they mentioned using an LLM to do the conversion I lost all interest. It's like saying "I wanted this done so I got my underling to do it, here is my story...". Like why would I bother to read it then, as it was clearly not you doing the conversion or putting any thought into it.
- eager_learner 5mo ago
  you sound jealous :)
  - shevy-java 5mo ago
    That's an assumption. How do you infer that from written text? I can not infer that. To me it is super-strange that one uses AI to come to the conclusion that language x is better than language y. In the past people spent some time using both languages for a while, before reaching any conclusion. With AI it seems insta-gratification or insta-evaluation now. I am beginning to see why Google ruined its search engine for real humans - those who control AI rule the world now. People aren't even noticing this how dependent they are becoming on AI in general.
    - eager_learner 5mo ago
      My experience tells me. You are disagreeing with me, but you don't give negative vibes in your comment. The other comment sounded too negative: << I lost all interest >> << why would I bother >> << putting any thought into it >> It could have been worded neutrally and still convey the same points of disagreement. Interestingly, look at their other comments, they are all contentious. I was also experimenting psychologically, to see what reactions I would get.
- pjmlp 5mo ago
  The biggest problem is that this is software development going forward. Programming languages don't really matter outside craft programming. As LLM improve, it will eventually be a matter to specify in which kind of language the specification should be generated. The UML and RUP crowd has had their vengeance.
  - daemin 5mo ago
    It doesn't have to be, we have the power to change it by just not using LLMs to generate code-like text sequences. But if anyone is having their revenge it is the "idea guys", not the UML jockeys.
    - pjmlp 5mo ago
      As long as upper management is measuring AI tools at work not much power is left. The whole idea with UML jockeys is that we no longer need brick layers, that is the whole point of software factory concepts, and stuff like Rational Unified Process. The only difference is using markdown this time around.
  - kajaktum 5mo ago
    That does not explain why people think their project that is 99% written by LLM is worth sharing.
    - xlii 5mo ago
      Post ain't about project written in LLM (and Rust one have 6 months in good ol' craft code) but about contrast between two variants. While personally I'm skeptical about LLM usage (and vibe coding in general) I'm not going to pretend it doesn't exist just on principle. I wouldn't risk rewrite 6 months worth of code to Rails but it's a perfectly good case for LLM conversion.
- oneneptune 5mo ago
  The biggest problem is the author didn't even bother to verify it. I've seen big multi-model ralph wiggum or whatevers do a conversion. Run for 6 hours. Upon manual inspection to understand how it handled some tricky calculations / logic I find stubs and hard coded truthy returns. So even if you ran a smoke test suite against it -- you'd think it successful...
- xlii 5mo ago
  The point isn't about writing it but seeing difference and making probably suboptimal choice. I mentioned in other comment that I reviewed it extensively. It's not a big project so outside of a few spicy bits it's mostly a web app. I'd say that saying "not putting thought into it" is unfair. I didn't push the button and YOLO. I did research about the tradeoffs and consequences. Snippets of Rust code vs Rails are the real thing and testability of Rust app is something I spent 2 months on. As LLM enthusiast would say: context matters ;)
october8140 5mo ago
I'm not sure any language + framework prioritizes developer happiness as much as Ruby on Rails.
- ch4s3 5mo ago
  I get a similar feeling from Elixir and Phoenix without the method_missing foot gun.
  - deleted 5mo ago
    [deleted]
- milch 5mo ago
  I don't think I've ever been unhappier than working on a Rails project. See a bug on the site - something is rendering incorrectly. grep to find the view. Great, there's a method that is being called to render the buggy section. Grep for the method name - 0 hits. Amazing, it's something that is synthesized somewhere and I have no idea where. Guess I'll stop what I'm doing and read docs for an hour. If you do nothing but use Rails all day, sure, but the whole convention over configuration thing is such a huge anti pattern to me.
  - deleted 5mo ago
    [deleted]
  - craigmcnamara 5mo ago
    method(:name).source is your friend
    - chao- 5mo ago
      `method(:name).source_location`, but yes. Ruby is very introspect-able and it is fantastic.
  - jimbokun 5mo ago
    I’ve had similar experiences with Spring Boot Java applications. Methods in stack traces that don’t exist in source code but are magicked into existence by annotations.
h4kunamata 5mo ago
From whatever to Go ... hype! From Go to Rust ... hype! From Rust to Ruby ... the new hype!?
- citbl 5mo ago
  With an LLM. So next week he can write about JavaScript and the next.
JSR_FDED 5mo ago
To count lines of rust code: fd . -e rs -uu | xargs cat | wc -l Why not just: find . -name '*.rs' | xargs wc -l
- cauterize 5mo ago
  Or tokei
encodedrose 5mo ago
>But before I did so I researched first. I asked a few instances to analyse the project in terms of gains of complexity, stability, testability, etc., and while (obviously) stability would drop (no types in Ruby) it’s not that awful (Sorbet has types in Ruby!). Is it not a rage-bait argument to say that not having types implies less stability?
- lmm 5mo ago
  No? Maybe the industry can now talk maturely about tradeoffs like that rather than pretending they don't exist.
honeybadger223 5mo ago
Idk why people are shitting on you. So many LLM haters on here. It’s changed the game completely and some people just don’t want to accept it. I think this is cool. Verbosity of languages is important when it comes to coding with AI. I’ve found Go to be a happy medium.
- loktarogar 5mo ago
  If you replaced "AI" with "a developer" in this article, it might make more sense why it's being dunked on. It would be an article about someone telling someone to do something, and then when the work was done they were happy with the result. It's just a bit of a nothing all round
  - cwyers 5mo ago
    > and then when the work was done they were happy with the result It's worse than that -- they don't even know the result! They never tried to run it!
    - loktarogar 5mo ago
      oh yeah - in this case the result is that the code was smaller and they were happy with that. correctness was not a criteria
- xigoi 5mo ago
  They wrote a blog post about code that they have not even tried running. Whether it’s LLM-generated does not matter.
JSR_FDED 5mo ago
This defies belief. “I wanted to scratch a technical itch. My local AI completed the job in 30 minutes. I never pressed Start to see if it works, but I did write a blog post about it…”
- otabdeveloper4 5mo ago
  > This defies belief. Akshually it's pretty normal for 2026.
  - sevenzero 5mo ago
    Yup, since the rise of AI, I still didn't find any product built by it that's even remotely useful to me... People build prototypes a lot, but these are usually buggy and not worth putting money into.
- iririririr 5mo ago
  * it wrote a blog post
  - xlii 5mo ago
    I assure you Sir/Madam no LLMs were harmed in this post. Grammar would've been much better :)
- torben-friis 5mo ago
  It's the first article on the frontpage now, which means that it doesn't matter the project doesn't work because the readers didn't read. (Unless bot-pushed of course)
- xlii 5mo ago
  I did however review it over 5 hours. So ¯\_(ツ)_/¯
- citbl 5mo ago
  2016 check out my new JavaScript Library! 2026 check out the work I didn't write! 2036 how I've written 200 lines in this ancient Latin called C
digitaltrees 5mo ago
I built a set of gems (propel_rails) that takes the already terse Ruby on Rails code to the next extreme. It generates a set of top level classes like an API controller and some concerns that then create a full restful resource (model, controller, serializer, unit and e2e tests) with 0 boilerplate code. The controller ends up being only a list of all permitted attributes the api will accept because the restful actions are automatically generated. It’s a bit hard to fully describe but the meta programming power of Ruby really does make amazing things easy.
- nine_k 5mo ago
  This sounds like CRUD, distilled. I suppose it works in terms of your domain model?
  - digitaltrees 5mo ago
    It sets up automatic filters, sorting, multi tenancy, authorization, and uses “accepts nested attributes for” to make it more graphic like that simply crud
- dajonker 5mo ago
  I can find it on rubygems but the link there to GitHub returns a 404.
  - digitaltrees 5mo ago
    Ah. It’s currently private. I haven’t open sourced it yet :)
nine_k 5mo ago
If you can switch from Rust to Ruby, and it would make sense, choosing Rust in the beginning was a mistake.
- xlii 5mo ago
  Thats a great summary of the piece and a reason why I decided to share.
tail_exchange 5mo ago
[dead]
rtpg 5mo ago
I do wonder if it'll ever be possible to get Rust tests to feel as nice to write as, say, test suites in Python or Ruby. I might just be missing a lot of helpers, but a part of me really wants to use a test metalanguage that (for example) RC's everything, gives me implicit casts from strings to what ever type I need, and a bunch of other stuff. I've always found Rust object buildup to be pretty annoying.
- aabhay 5mo ago
  dbg! Is your friend
- ryanshrott 5mo ago
  [dead]
faangguyindia 5mo ago
People think Ruby is slower than Rust, they'll be surprised to know Ruby is actually now faster than python but slower than Go or Rust.
- Gigachad 5mo ago
  Speed has usually mattered less to me than memory usage. Most Ruby applications are speed limited by the database rather than Ruby. But when you have a bunch of background workers, every one chewing 2+ gb of memory stacks up. I wrote one production Rust service and more impressive than the speed was that the thing ran on 30MB memory.
  - faangguyindia 5mo ago
    I use Go for the same reason, but it seems php can use even less memory.
- latexr 5mo ago
  Why would someone who thinks Ruby is slower than Rust (which apparently includes you) be surprised it’s faster than Python? Why does one thing have to do with the other?
  - jasdfasd8 5mo ago
    I think they are jesting: https://news.ycombinator.com/item?id=48245262#48246312 https://news.ycombinator.com/item?id=48245262#48246312
c0balt 5mo ago
I'm sometimes amazed by project sizes, a 30k line codebase is small? I'm aware that the ceiling is high but 30k lines of code can encode so much information and behavioural nuance. Maybe this is just my backend/network focus with Golang though. Scaling beyond 10-15k lines of code always was quite intimidating as it is usually where I lose the ability to just keep a model of the codebase fully in my head.
- ramon156 5mo ago
  Heavily depends on what you're building. A SaaS app with multiple front ends will easily hit 30k.
shevy-java 5mo ago
> So I had to take a look around to remind myself what Ruby and Ruby on Rails are doing nowadays. They’re doing quite well. Ah really? Well ... let's look at TIOBE. Now I am aware that TIOBE sucks, it makes little sense, but even with that in mind, the claim that ruby is doing that well is simply factually WRONG, at the least right now: https://www.tiobe.com/tiobe-index/ https://www.tiobe.com/tiobe-index/ Ruby is ranked 23. Rust is ranked 15. Again, TIOBE has tons of issues, people pointed that out, but I am pointing here more at a trend. If you look at the graph: https://www.tiobe.com/tiobe-index/ruby/ https://www.tiobe.com/tiobe-index/ruby/ It is more obvious. Now, I think ruby is a great language, I use it daily as the primary glue language to do literally everything. I call it the ultimate wrapper over C, which ruby ultimately is. But the claim "ruby is doing great" is just simply INCORRECT. And we haven't even gotten to RubyCentral mass-purging developers or adding random new corporate-driven rules to rubygems.org and what not. I never understood why I would be under 100k download restrictions when on github I have full control over my own (!!!) code. I call that an illegal hijacking attempt by RubyCentral (this was about a year before they mass-purged developers anyway, so I could nod my head wisely when that happened lateron, even though I had no advance knowledge, but it did not surprise me once the shopify corporate overlord pulled rank; and DHH sitting on the sidelines making joyful comments at the chaotic situation here on his blog. At that time I noticed that DHH indeed became a problem too). > There are some typing initiatives (Sorbet), and the language itself is terse as ever. No sane rubyist uses that typing crap, sorry. And matz isn't the biggest fan of slapping down mandatory types onto everything either. People whose brain is addicted to types, want them; I understand that problem. There is no way you can reason with them because they really WANT types. It's like someone starving for food; that person wants food. There is no way around that. Same with types for these people. And they want to change a language to that too. This is the annoying part. Many years ago I was surprised to hear haskell folks not wanting everyone. After that type addiction, I realise the haskell point of view: some people want to ruin languages. (You may debate whether types ruin ruby or not, but the main point here is that some people want to change a language into something that fits their brain more easily. Now I understand the haskell point of view, despite still thinking this is a snobbish elitist view of exclusion. But language integrity is also indeed important, so I understand that point of view these days.) > while (obviously) stability would drop (no types in Ruby) Absolute rubbish nonsense. Absolute. Totally incorrect claim made, from A to Z. But again, you can not reason with these type addiction people. Can't they go to PHP or some other language? Let's reword it more neutrally then. Which claims and proof support the claim that stability drops because of "no types in Ruby"? Because I never ever had that happen in any code I wrote in ruby in the last +20 years. Yes, you need to be able to query what is possible; often you may have to do .is_a? or .respond_to?. Yes, this is not the same as "advance" type checks. I am not saying types are useless either. What I am saying is that the claim of "you lose stability without types" is ABSOLUTELY RUBBISH NONSENSE. But the brain of type-addicted folks is already set towards "types everywhere". This is the problem. They are trapped in their world of assumptions. > So in the end it seems I have (licks finger and turns to the wind) 1.47x better outcomes if the app were a Ruby on Rails app instead. Now he is pulling numbers out of ... > I have a local LLM running on my (bought it for gaming pre-AI craze) 4090 Ti1 - I’m a free man with unlimited tokens2. So I thought: BRING IT ON! Ah - and AI already deadlocked his brain on top of that. So not even writing any ruby code but just using AI. And using Rails either. Well, you can write web-applications without rails too. And that works extremely well. That also was the first thing I did when I switched from PHP to ruby back then. And I still don't need or use rails either. > Since it is a relatively small project the conversion took ~30 minutes. I have no idea if it works or not because I haven’t yet tried running it. But there is one thing I checked, and stared at in horror So he used AI and still has absolutely no idea about anything. These people don't see a problem with that. Oldschool people didn't go that way. > That’s right folks! 77% decrease in line count; 4.49 lines of Rust code for each line of Ruby. Well, using python would also have led to a significant decrease, so that is not surprising. C and C++ and Java also require a lot more information. Types in particular require more syntax and words in general, so really - nothing surprising here. That ruby is succinct and still elegant (except for this type crap) is one reason why people often stick to ruby. > but I must say it’s looking clean and idiomatic for my dated eye. But he is using AI here. How does he know that it is clean and idiomatic? The ruby code I write is (to me) very simple and straightforward, typical OOP but simple and practical at all times (whenever possible). AI does not generate such code. And a ton of ruby code on the world wide web, written by humans, looks as if someone beat you silly with a club on the head, before you started to write anything. Even well-used projects such as rack - anyone looked at the source code? Or of sinatra? It looks as if someone was drunk when writing the code. I am biased myself though; for instance, I find Jeremy Evans typically writes elegant ruby code. zverok writes fascinating projects, but his writing style is totally alien to me - your mileage may vary. The point is that there is not really a unified "idiomatic" ruby code. Look at this for instance: https://github.com/ruby/ruby/blob/trunk/test/ruby/test_thread.rb#L191 https://github.com/ruby/ruby/blob/trunk/test/ruby/test_threa... The code was as follows (the link no longer worked, I bookmarked it some years ago and now I can not find the new code but I assure everyone that this was that way, because I stored it locally): t1&.kill&.join The safe navigation syntax has use cases, I am not denying that either. You can shorten some code significantly. But I find this syntax utterly horrible and decided that my code base will be protected against safe navigation horror. Of course this is a subjective opinion. But ruby syntax is not automatically great merely because it is ruby. You need to think what you want and even more importantly what you don't want. And why. > I can add types using Agents, so probably type safety can be alleviated Yikes. And the worst part is: type-addicted people can not modify their brain. I've never seen a type-loving person abandon this love for types. > Ruby/Rails is pretty much batteries+kitchen sink included, which beats 3GiB of compiled deps. Ok. Not disputing that. But that more says a lot about Rust than Ruby really. Because the main question should be why you need so much code in Rust for that. > Testing will be SO MUCH EASIER Not disputing that either. This is probably one of the strangest blog statements I have ever read. I think ruby is a great programming language, but this AI-powered transition is just ... strange. Basically he is not really using ruby. But praises ruby. While having AI generate the code. Am I the only one to find this extremely awkward?
preommr 5mo ago
> So in the end it seems I have (licks finger and turns to the wind) 1.47x better outcomes if the app were a Ruby on Rails app instead. Am I reading this right... did this number just come out of thin air? Is this just generated based on the vibes of the AI? Also, to just add them up and compare them like that is just compounding nonsense on nonsense.
- Ocha 5mo ago
  Tell me you haven’t actually taken engineering class by not telling me you haven’t taken an engineering class
  - Ocha 5mo ago
    Hint: weighted sum
    - kelnos 5mo ago
      Of what, though? A weird subjective pulled-out-of-the-ass rating system, with also pulled-out-of-the-ass weights? I think that's where GGP's confusion comes from.
shotgun 5mo ago
Next try Elixir.
ramon156 5mo ago
Hey I'm in the same boat! I love Go and Rust, they're wonderful languages with their own ups and downs. Sadly I never was able to build a SaaS app with either. Something about a square peg and a round hole... I could be very wrong, but there's a lot of gadgets that come with a SaaS tool, and I'm not inventing them. RoR is.. "good enough". I can opt-in types whenever, I can build things quick, the tooling is alright, etc. My first real job was PHP, and there were just too many gotchas there. Ruby seems to steer a bit more towards ecommerce, which intruiged me. And its good enough for Shopify, so...
zareith 5mo ago
Curious if there are folks (perhaps from ruby community) using crystal for medium/large projects. How has your experience been? I recently tried it out in a hobby project and was pleasantly surprised at how smooth the overall DX was, and how little memory it consumed.
- prmoustache 5mo ago
  Is there such thing as rails for crystal?
  - zareith 5mo ago
    Marten and Lucky come close. My use cases are fairly minimal though, and the adjacent ecosystem is not as well developed. You likely won't be able to get an out of the box integrated gems for shopping cart, blogging platform, newsletter, analytics etc. as you might for rails. If you are building something new from basic blocks, a lot of the foundational blocks seem to be good state. But again, my experience is very limited.
rballpug 5mo ago
Mounting Debian from LAN on GRUB as bootloader, which is typical for x64_86 motherboards. Iterating /src/ is transforming language in compiler.
wg0 5mo ago
Trigger alert - While it is good to signal your 900+ IQ to the peasants around you,many many smart and talented developers don't like rust so much so that they'll prefer writing their own programming language and their own compiler over writing single line of Rust. Jai and Odin come to mind with Jonathan Blow and Ginger Bill. Many many more folks that are capable of (and have) written widely used beautiful libraries and frameworks that are evidence of their creativity and depth but we don't want to waste space here. Rust however has a lovely Macho club a good brotherhood.
- maleldil 5mo ago
  The Rust community is as far from a "macho club" as it can possibly be.
IshKebab 5mo ago
> Rust is verbose It's really not that verbose. I rewrote a Python project in Rust. It was about 10% more lines of code. If they're seeing a bit difference it's definitely an outlier or they're doing something horribly wrong.
temphaaa 5mo ago
sorry for the bluntness, but you should have probably thought twice before hitting the send to Hacker News button, i didn't find this in any way interesting and i am definitively not a LLM hater
prakashn27 5mo ago
I always check hn comments before viewing the article . The comments alone saved me lot of time for not viewing the article
andrewmutz 5mo ago
Claude works in Rails apps extremely well. As the author of this blog points points out, Ruby allows you to get a ton done with minimal coding. Also, Rails uses convention over configuration, making Rails apps even terser. One hypothesis for the effectiveness of Claude writing Rails apps is its token efficiency. I ran across this project awhile back that attempts to measure and compare the token efficiency across projects, and Rails does really well: https://felipemrvieira.github.io/SyntaxTax/dashboard/ https://felipemrvieira.github.io/SyntaxTax/dashboard/
jt-hill 5mo ago
> I have no idea if it works or not because I haven’t yet tried running it. This should have been disclosed in the first paragraph

From Rust to Ruby

127 points by xlii 5mo ago

lmm 5mo ago

"I have no idea if it works or not because I haven’t yet tried running it. But it's 5x shorter!"

october8140 5mo ago
The fact that it doesn't end with what happens when they run `rails server` makes me think they did it and didn't like the results.
pahbloo 5mo ago
Not a xkcd, but quite relevant: https://web.archive.org/web/20091015091833/http://www.hackles.org/cgi-bin/archives.pl?request=310 https://web.archive.org/web/20091015091833/http://www.hackle...

daemin 5mo ago

At first I thought this would be an interesting article, but as soon as they mentioned using an LLM to do the conversion I lost all interest. It's like saying "I wanted this done so I got my underling to do it, here is my story...". Like why would I bother to read it then, as it was clearly not you doing the conversion or putting any thought into it.

eager_learner 5mo ago
you sound jealous :)
- shevy-java 5mo ago
  That's an assumption. How do you infer that from written text? I can not infer that. To me it is super-strange that one uses AI to come to the conclusion that language x is better than language y. In the past people spent some time using both languages for a while, before reaching any conclusion. With AI it seems insta-gratification or insta-evaluation now. I am beginning to see why Google ruined its search engine for real humans - those who control AI rule the world now. People aren't even noticing this how dependent they are becoming on AI in general.
  - eager_learner 5mo ago
    My experience tells me. You are disagreeing with me, but you don't give negative vibes in your comment. The other comment sounded too negative: << I lost all interest >> << why would I bother >> << putting any thought into it >> It could have been worded neutrally and still convey the same points of disagreement. Interestingly, look at their other comments, they are all contentious. I was also experimenting psychologically, to see what reactions I would get.
pjmlp 5mo ago
The biggest problem is that this is software development going forward. Programming languages don't really matter outside craft programming. As LLM improve, it will eventually be a matter to specify in which kind of language the specification should be generated. The UML and RUP crowd has had their vengeance.
- daemin 5mo ago
  It doesn't have to be, we have the power to change it by just not using LLMs to generate code-like text sequences. But if anyone is having their revenge it is the "idea guys", not the UML jockeys.
  - pjmlp 5mo ago
    As long as upper management is measuring AI tools at work not much power is left. The whole idea with UML jockeys is that we no longer need brick layers, that is the whole point of software factory concepts, and stuff like Rational Unified Process. The only difference is using markdown this time around.
- kajaktum 5mo ago
  That does not explain why people think their project that is 99% written by LLM is worth sharing.
  - xlii 5mo ago
    Post ain't about project written in LLM (and Rust one have 6 months in good ol' craft code) but about contrast between two variants. While personally I'm skeptical about LLM usage (and vibe coding in general) I'm not going to pretend it doesn't exist just on principle. I wouldn't risk rewrite 6 months worth of code to Rails but it's a perfectly good case for LLM conversion.
oneneptune 5mo ago
The biggest problem is the author didn't even bother to verify it. I've seen big multi-model ralph wiggum or whatevers do a conversion. Run for 6 hours. Upon manual inspection to understand how it handled some tricky calculations / logic I find stubs and hard coded truthy returns. So even if you ran a smoke test suite against it -- you'd think it successful...
xlii 5mo ago
The point isn't about writing it but seeing difference and making probably suboptimal choice. I mentioned in other comment that I reviewed it extensively. It's not a big project so outside of a few spicy bits it's mostly a web app. I'd say that saying "not putting thought into it" is unfair. I didn't push the button and YOLO. I did research about the tradeoffs and consequences. Snippets of Rust code vs Rails are the real thing and testability of Rust app is something I spent 2 months on. As LLM enthusiast would say: context matters ;)

october8140 5mo ago

I'm not sure any language + framework prioritizes developer happiness as much as Ruby on Rails.

ch4s3 5mo ago
I get a similar feeling from Elixir and Phoenix without the method_missing foot gun.
- deleted 5mo ago
  [deleted]
milch 5mo ago
I don't think I've ever been unhappier than working on a Rails project. See a bug on the site - something is rendering incorrectly. grep to find the view. Great, there's a method that is being called to render the buggy section. Grep for the method name - 0 hits. Amazing, it's something that is synthesized somewhere and I have no idea where. Guess I'll stop what I'm doing and read docs for an hour. If you do nothing but use Rails all day, sure, but the whole convention over configuration thing is such a huge anti pattern to me.
- deleted 5mo ago
  [deleted]
- craigmcnamara 5mo ago
  method(:name).source is your friend
  - chao- 5mo ago
    `method(:name).source_location`, but yes. Ruby is very introspect-able and it is fantastic.
- jimbokun 5mo ago
  I’ve had similar experiences with Spring Boot Java applications. Methods in stack traces that don’t exist in source code but are magicked into existence by annotations.

h4kunamata 5mo ago

From whatever to Go ... hype! From Go to Rust ... hype! From Rust to Ruby ... the new hype!?

citbl 5mo ago
With an LLM. So next week he can write about JavaScript and the next.

JSR_FDED 5mo ago

To count lines of rust code: fd . -e rs -uu | xargs cat | wc -l Why not just: find . -name '*.rs' | xargs wc -l

cauterize 5mo ago
Or tokei

encodedrose 5mo ago

>But before I did so I researched first. I asked a few instances to analyse the project in terms of gains of complexity, stability, testability, etc., and while (obviously) stability would drop (no types in Ruby) it’s not that awful (Sorbet has types in Ruby!). Is it not a rage-bait argument to say that not having types implies less stability?

lmm 5mo ago
No? Maybe the industry can now talk maturely about tradeoffs like that rather than pretending they don't exist.

honeybadger223 5mo ago

Idk why people are shitting on you. So many LLM haters on here. It’s changed the game completely and some people just don’t want to accept it. I think this is cool. Verbosity of languages is important when it comes to coding with AI. I’ve found Go to be a happy medium.

loktarogar 5mo ago
If you replaced "AI" with "a developer" in this article, it might make more sense why it's being dunked on. It would be an article about someone telling someone to do something, and then when the work was done they were happy with the result. It's just a bit of a nothing all round
- cwyers 5mo ago
  > and then when the work was done they were happy with the result It's worse than that -- they don't even know the result! They never tried to run it!
  - loktarogar 5mo ago
    oh yeah - in this case the result is that the code was smaller and they were happy with that. correctness was not a criteria
xigoi 5mo ago
They wrote a blog post about code that they have not even tried running. Whether it’s LLM-generated does not matter.

JSR_FDED 5mo ago

This defies belief. “I wanted to scratch a technical itch. My local AI completed the job in 30 minutes. I never pressed Start to see if it works, but I did write a blog post about it…”

otabdeveloper4 5mo ago
> This defies belief. Akshually it's pretty normal for 2026.
- sevenzero 5mo ago
  Yup, since the rise of AI, I still didn't find any product built by it that's even remotely useful to me... People build prototypes a lot, but these are usually buggy and not worth putting money into.
iririririr 5mo ago
* it wrote a blog post
- xlii 5mo ago
  I assure you Sir/Madam no LLMs were harmed in this post. Grammar would've been much better :)
torben-friis 5mo ago
It's the first article on the frontpage now, which means that it doesn't matter the project doesn't work because the readers didn't read. (Unless bot-pushed of course)
xlii 5mo ago
I did however review it over 5 hours. So ¯\_(ツ)_/¯
citbl 5mo ago
2016 check out my new JavaScript Library! 2026 check out the work I didn't write! 2036 how I've written 200 lines in this ancient Latin called C

digitaltrees 5mo ago

I built a set of gems (propel_rails) that takes the already terse Ruby on Rails code to the next extreme. It generates a set of top level classes like an API controller and some concerns that then create a full restful resource (model, controller, serializer, unit and e2e tests) with 0 boilerplate code. The controller ends up being only a list of all permitted attributes the api will accept because the restful actions are automatically generated. It’s a bit hard to fully describe but the meta programming power of Ruby really does make amazing things easy.

nine_k 5mo ago
This sounds like CRUD, distilled. I suppose it works in terms of your domain model?
- digitaltrees 5mo ago
  It sets up automatic filters, sorting, multi tenancy, authorization, and uses “accepts nested attributes for” to make it more graphic like that simply crud
dajonker 5mo ago
I can find it on rubygems but the link there to GitHub returns a 404.
- digitaltrees 5mo ago
  Ah. It’s currently private. I haven’t open sourced it yet :)

nine_k 5mo ago

If you can switch from Rust to Ruby, and it would make sense, choosing Rust in the beginning was a mistake.

xlii 5mo ago
Thats a great summary of the piece and a reason why I decided to share.

tail_exchange 5mo ago

[dead]

rtpg 5mo ago

I do wonder if it'll ever be possible to get Rust tests to feel as nice to write as, say, test suites in Python or Ruby. I might just be missing a lot of helpers, but a part of me really wants to use a test metalanguage that (for example) RC's everything, gives me implicit casts from strings to what ever type I need, and a bunch of other stuff. I've always found Rust object buildup to be pretty annoying.

aabhay 5mo ago
dbg! Is your friend
ryanshrott 5mo ago
[dead]

faangguyindia 5mo ago

People think Ruby is slower than Rust, they'll be surprised to know Ruby is actually now faster than python but slower than Go or Rust.

Gigachad 5mo ago
Speed has usually mattered less to me than memory usage. Most Ruby applications are speed limited by the database rather than Ruby. But when you have a bunch of background workers, every one chewing 2+ gb of memory stacks up. I wrote one production Rust service and more impressive than the speed was that the thing ran on 30MB memory.
- faangguyindia 5mo ago
  I use Go for the same reason, but it seems php can use even less memory.
latexr 5mo ago
Why would someone who thinks Ruby is slower than Rust (which apparently includes you) be surprised it’s faster than Python? Why does one thing have to do with the other?
- jasdfasd8 5mo ago
  I think they are jesting: https://news.ycombinator.com/item?id=48245262#48246312 https://news.ycombinator.com/item?id=48245262#48246312

c0balt 5mo ago

I'm sometimes amazed by project sizes, a 30k line codebase is small? I'm aware that the ceiling is high but 30k lines of code can encode so much information and behavioural nuance. Maybe this is just my backend/network focus with Golang though. Scaling beyond 10-15k lines of code always was quite intimidating as it is usually where I lose the ability to just keep a model of the codebase fully in my head.

ramon156 5mo ago
Heavily depends on what you're building. A SaaS app with multiple front ends will easily hit 30k.

shevy-java 5mo ago

> So I had to take a look around to remind myself what Ruby and Ruby on Rails are doing nowadays. They’re doing quite well. Ah really? Well ... let's look at TIOBE. Now I am aware that TIOBE sucks, it makes little sense, but even with that in mind, the claim that ruby is doing that well is simply factually WRONG, at the least right now: https://www.tiobe.com/tiobe-index/ https://www.tiobe.com/tiobe-index/ Ruby is ranked 23. Rust is ranked 15. Again, TIOBE has tons of issues, people pointed that out, but I am pointing here more at a trend. If you look at the graph: https://www.tiobe.com/tiobe-index/ruby/ https://www.tiobe.com/tiobe-index/ruby/ It is more obvious. Now, I think ruby is a great language, I use it daily as the primary glue language to do literally everything. I call it the ultimate wrapper over C, which ruby ultimately is. But the claim "ruby is doing great" is just simply INCORRECT. And we haven't even gotten to RubyCentral mass-purging developers or adding random new corporate-driven rules to rubygems.org and what not. I never understood why I would be under 100k download restrictions when on github I have full control over my own (!!!) code. I call that an illegal hijacking attempt by RubyCentral (this was about a year before they mass-purged developers anyway, so I could nod my head wisely when that happened lateron, even though I had no advance knowledge, but it did not surprise me once the shopify corporate overlord pulled rank; and DHH sitting on the sidelines making joyful comments at the chaotic situation here on his blog. At that time I noticed that DHH indeed became a problem too). > There are some typing initiatives (Sorbet), and the language itself is terse as ever. No sane rubyist uses that typing crap, sorry. And matz isn't the biggest fan of slapping down mandatory types onto everything either. People whose brain is addicted to types, want them; I understand that problem. There is no way you can reason with them because they really WANT types. It's like someone starving for food; that person wants food. There is no way around that. Same with types for these people. And they want to change a language to that too. This is the annoying part. Many years ago I was surprised to hear haskell folks not wanting everyone. After that type addiction, I realise the haskell point of view: some people want to ruin languages. (You may debate whether types ruin ruby or not, but the main point here is that some people want to change a language into something that fits their brain more easily. Now I understand the haskell point of view, despite still thinking this is a snobbish elitist view of exclusion. But language integrity is also indeed important, so I understand that point of view these days.) > while (obviously) stability would drop (no types in Ruby) Absolute rubbish nonsense. Absolute. Totally incorrect claim made, from A to Z. But again, you can not reason with these type addiction people. Can't they go to PHP or some other language? Let's reword it more neutrally then. Which claims and proof support the claim that stability drops because of "no types in Ruby"? Because I never ever had that happen in any code I wrote in ruby in the last +20 years. Yes, you need to be able to query what is possible; often you may have to do .is_a? or .respond_to?. Yes, this is not the same as "advance" type checks. I am not saying types are useless either. What I am saying is that the claim of "you lose stability without types" is ABSOLUTELY RUBBISH NONSENSE. But the brain of type-addicted folks is already set towards "types everywhere". This is the problem. They are trapped in their world of assumptions. > So in the end it seems I have (licks finger and turns to the wind) 1.47x better outcomes if the app were a Ruby on Rails app instead. Now he is pulling numbers out of ... > I have a local LLM running on my (bought it for gaming pre-AI craze) 4090 Ti1 - I’m a free man with unlimited tokens2. So I thought: BRING IT ON! Ah - and AI already deadlocked his brain on top of that. So not even writing any ruby code but just using AI. And using Rails either. Well, you can write web-applications without rails too. And that works extremely well. That also was the first thing I did when I switched from PHP to ruby back then. And I still don't need or use rails either. > Since it is a relatively small project the conversion took ~30 minutes. I have no idea if it works or not because I haven’t yet tried running it. But there is one thing I checked, and stared at in horror So he used AI and still has absolutely no idea about anything. These people don't see a problem with that. Oldschool people didn't go that way. > That’s right folks! 77% decrease in line count; 4.49 lines of Rust code for each line of Ruby. Well, using python would also have led to a significant decrease, so that is not surprising. C and C++ and Java also require a lot more information. Types in particular require more syntax and words in general, so really - nothing surprising here. That ruby is succinct and still elegant (except for this type crap) is one reason why people often stick to ruby. > but I must say it’s looking clean and idiomatic for my dated eye. But he is using AI here. How does he know that it is clean and idiomatic? The ruby code I write is (to me) very simple and straightforward, typical OOP but simple and practical at all times (whenever possible). AI does not generate such code. And a ton of ruby code on the world wide web, written by humans, looks as if someone beat you silly with a club on the head, before you started to write anything. Even well-used projects such as rack - anyone looked at the source code? Or of sinatra? It looks as if someone was drunk when writing the code. I am biased myself though; for instance, I find Jeremy Evans typically writes elegant ruby code. zverok writes fascinating projects, but his writing style is totally alien to me - your mileage may vary. The point is that there is not really a unified "idiomatic" ruby code. Look at this for instance: https://github.com/ruby/ruby/blob/trunk/test/ruby/test_thread.rb#L191 https://github.com/ruby/ruby/blob/trunk/test/ruby/test_threa... The code was as follows (the link no longer worked, I bookmarked it some years ago and now I can not find the new code but I assure everyone that this was that way, because I stored it locally): t1&.kill&.join The safe navigation syntax has use cases, I am not denying that either. You can shorten some code significantly. But I find this syntax utterly horrible and decided that my code base will be protected against safe navigation horror. Of course this is a subjective opinion. But ruby syntax is not automatically great merely because it is ruby. You need to think what you want and even more importantly what you don't want. And why. > I can add types using Agents, so probably type safety can be alleviated Yikes. And the worst part is: type-addicted people can not modify their brain. I've never seen a type-loving person abandon this love for types. > Ruby/Rails is pretty much batteries+kitchen sink included, which beats 3GiB of compiled deps. Ok. Not disputing that. But that more says a lot about Rust than Ruby really. Because the main question should be why you need so much code in Rust for that. > Testing will be SO MUCH EASIER Not disputing that either. This is probably one of the strangest blog statements I have ever read. I think ruby is a great programming language, but this AI-powered transition is just ... strange. Basically he is not really using ruby. But praises ruby. While having AI generate the code. Am I the only one to find this extremely awkward?

preommr 5mo ago

> So in the end it seems I have (licks finger and turns to the wind) 1.47x better outcomes if the app were a Ruby on Rails app instead. Am I reading this right... did this number just come out of thin air? Is this just generated based on the vibes of the AI? Also, to just add them up and compare them like that is just compounding nonsense on nonsense.

Ocha 5mo ago
Tell me you haven’t actually taken engineering class by not telling me you haven’t taken an engineering class
- Ocha 5mo ago
  Hint: weighted sum
  - kelnos 5mo ago
    Of what, though? A weird subjective pulled-out-of-the-ass rating system, with also pulled-out-of-the-ass weights? I think that's where GGP's confusion comes from.

shotgun 5mo ago

Next try Elixir.

ramon156 5mo ago

Hey I'm in the same boat! I love Go and Rust, they're wonderful languages with their own ups and downs. Sadly I never was able to build a SaaS app with either. Something about a square peg and a round hole... I could be very wrong, but there's a lot of gadgets that come with a SaaS tool, and I'm not inventing them. RoR is.. "good enough". I can opt-in types whenever, I can build things quick, the tooling is alright, etc. My first real job was PHP, and there were just too many gotchas there. Ruby seems to steer a bit more towards ecommerce, which intruiged me. And its good enough for Shopify, so...

zareith 5mo ago

Curious if there are folks (perhaps from ruby community) using crystal for medium/large projects. How has your experience been? I recently tried it out in a hobby project and was pleasantly surprised at how smooth the overall DX was, and how little memory it consumed.

prmoustache 5mo ago
Is there such thing as rails for crystal?
- zareith 5mo ago
  Marten and Lucky come close. My use cases are fairly minimal though, and the adjacent ecosystem is not as well developed. You likely won't be able to get an out of the box integrated gems for shopping cart, blogging platform, newsletter, analytics etc. as you might for rails. If you are building something new from basic blocks, a lot of the foundational blocks seem to be good state. But again, my experience is very limited.

rballpug 5mo ago

Mounting Debian from LAN on GRUB as bootloader, which is typical for x64_86 motherboards. Iterating /src/ is transforming language in compiler.

wg0 5mo ago

Trigger alert - While it is good to signal your 900+ IQ to the peasants around you,many many smart and talented developers don't like rust so much so that they'll prefer writing their own programming language and their own compiler over writing single line of Rust. Jai and Odin come to mind with Jonathan Blow and Ginger Bill. Many many more folks that are capable of (and have) written widely used beautiful libraries and frameworks that are evidence of their creativity and depth but we don't want to waste space here. Rust however has a lovely Macho club a good brotherhood.

maleldil 5mo ago
The Rust community is as far from a "macho club" as it can possibly be.

IshKebab 5mo ago

> Rust is verbose It's really not that verbose. I rewrote a Python project in Rust. It was about 10% more lines of code. If they're seeing a bit difference it's definitely an outlier or they're doing something horribly wrong.

temphaaa 5mo ago

sorry for the bluntness, but you should have probably thought twice before hitting the send to Hacker News button, i didn't find this in any way interesting and i am definitively not a LLM hater

prakashn27 5mo ago

I always check hn comments before viewing the article . The comments alone saved me lot of time for not viewing the article

andrewmutz 5mo ago

Claude works in Rails apps extremely well. As the author of this blog points points out, Ruby allows you to get a ton done with minimal coding. Also, Rails uses convention over configuration, making Rails apps even terser. One hypothesis for the effectiveness of Claude writing Rails apps is its token efficiency. I ran across this project awhile back that attempts to measure and compare the token efficiency across projects, and Rails does really well: https://felipemrvieira.github.io/SyntaxTax/dashboard/ https://felipemrvieira.github.io/SyntaxTax/dashboard/

jt-hill 5mo ago

> I have no idea if it works or not because I haven’t yet tried running it. This should have been disclosed in the first paragraph