Also worth noting that "translated from C++" Rust is totally fine as a starting point. You can incrementally make it more idiomatic later once the C++ side is retired. The Rust compiler will still catch whole classes of memory bugs even if the code reads a bit weird. That's the whole point.
> Way too many rewrites fail because people try to "improve" things during the port
I think the last one gets ignored easily but my favorite time to document code is when reading it (but the best time is when writing it). It forces you to think explicitly about what the code is doing and makes it harder for the little things to slip by. Given that Ladybird is a popular project I really do think good documentation is a way to accelerate its development. Good documentation means new people can come in and contribute faster and with fewer errors. It lowers the barrier to entry, substantially. It's also helpful for all the mere mortals who forget things
This is a HUUUGE reason code written in rust tended to be so much better than the original (which was probably written in c++).
Human expertise is the single most important factor and is more important than language.
Copy pasting from one language to another is way worse than complete rewrite with actual idiomatic and useful code.
Best option after proper rewrite is binding. And copy-paste with LLM comes way below these options imo.
If you look at real world, basically all value is created by boring and hated languages. Because people spent so much effort on making those languages useful, and other people spent so much effort learning and using those languages.
Don’t think anyone would prefer to work in a rust codebase that an LLM copy-pasted from c++, compared to working on a c++ codebase written by actual people that they can interact with.
This is the way. Coding assistants are also really great at porting from one language to the other, especially if you have existing tests.
I had a broken, one-off Perl script, a relic from the days when everyone thought Drupal was the future (long time ago). It was originally designed to migrate a site from an unmaintained internal CMS to Drupal. The CMS was ancient and it only ran in a VM for "look what we built a million years ago" purposes (I even had written permission from my ex-employer to keep that thing).
Just for a laugh, I fed this mess of undeclared dependencies and missing logic into Claude and told it to port the whole thing to Rust. It spent 80 minutes researching Drupal and coding, then "one-shotted" a functional import tool. Not only did it mirror the original design and module structure, but it also implemented several custom plugins based on hints it found in my old code comments.
It burned through a mountain of tokens, but 10/10 - would generate tens of thousands of lines of useless code again.
The Epilogue: That site has since been ported to WordPress, then ProcessWire, then rebuilt as a Node.js app. Word on the street is that some poor souls are currently trying to port it to Next.js.
Me too! A couple days ago I gave claude the JMAP spec and asked it to write a JMAP based webmail client in rust from scratch. And it did! It burned a mountain of tokens, and its got more than a few bugs. But now I've got my very own email client, powered by the stalwart email server. The rust code compiles into a 2mb wasm bundle that does everything client side. Its somehow insanely fast. Honestly, its the fastest email client I've ever used by far. Everything feels instant.
I don't need my own email client, but I have one now. So unnecessary, and yet strangely fun.
Its quite a testament to JMAP that you can feed the RFC into claude and get a janky client out. I wonder what semi-useless junk I should get it to make next? I bet it wouldn't do as good a job with IMAP, but maybe if I let it use an IMAP library someone's already made? Might be worth a try!
This is the biggest bottleneck at this point. I'm looking forward to RAM production increasing, and getting to a point where every high-end PC (workstation & gaming) has a dedicated NPU next to the GPU. You'll be able to do this kind of stuff as much as you want, using any local model you want. Run a ralph loop continuously for 72 hours? No problem.
Drupal is the future. I never really used it properly, but if you fully buy into Drupal, it can do most everything without programming, and you can write plugins (extensions? whatever they're called...) to do the few things that do need programming.
> The Epilogue: That site has since been ported to WordPress, then ProcessWire, then rebuilt as a Node.js app. Word on the street is that some poor souls are currently trying to port it to Next.js.
This is the problem! Fickle halfwits mindlessly buying into whatever "next big thing" is currently fashionable. They shoulda just learned Drupal...
Pardon me, and, yes, I know we're on HN, but I guess you're... rich? I imagine a single run like this probably burns through tens or hundreds of dollars. For a joke, basically.
I guess I understand why some people really like AI :-)
All of them are moving into the direction of "less human involved and agents do more", while what I really want is better tooling for me to work closer with AI and be better at reviewing/steering it, and be more involved. I don't want "Fire one prompt and get somewhat working code", I want a UX tailored for long sessions with back and forth, letting me leverage my skills, rather than agents trying to emulate what I already can do myself.
It was said a long time ago about computing in general, but more fitting than ever, "Augmenting the human intellect" is what we should aim for, not replacing the human intellect. IA ("Intelligence amplification") rather than AI.
But I'm guessing the target market for such tools would be much smaller, basically would require you to already understand software development, and know what you want, while all AI companies seem to target non-developers wanting to build software now. It's no-code all over again essentially.
Same thing.
Is that what you mean by IA?
For example, I type "for" and my editor guesses I want to iterate over the list that is the second argument of the function for which I am currently building the body. So it offers to complete the rest of the loop condition for me. Not only did it anticipate that I am writing a for loop. It figures out what I want to iterate over, and perhaps even that I want to enumerate the iteration so I have the index and the value. Imagine if I had written a comment to explain my intent for the function before I started writing the function body. How much better could it augment my intellect?
This is because, regardless of the current state of things, the endgame which will justify all the upfront investment is autonomous, self-improving, self-maintaining systems.
I want less ambitious LLM powered tools than what's being offered. For example, I'd love a tool that can analyse whether comments have been kept up to date with the code they refer to. I don't want it to change anything I just want it to tell me of any problems. A linter basically. I imagine LLMs would be a good foundation for this.
their valuations are replaced on getting rid of you entirely, along with everyone else
the "humans can use it to increase their productivity" is an interim step
I decided to create a Claude skill called "teach". When I enable it, Claude never writes any code. It just gives me hints - progressively more detailed if I am stuck. Then it reviews what I write.
I am finding it very satisfying to work this way - Rust in particular is a language where there's little space to "wing it". Most language features are interlaced with each other and having an LLM supporting me helps a lot. "Let's not declare a type for this right now, we would have to deal with several lifetime issues, let's add a note to the plan and revisit this later".
This link also has a comparison to Skills further down.
https://code.claude.com/docs/en/output-styles#built-in-outpu...
I used Claude to rewrite it in golang and extend its features. Now I have tests, automatic AIA chain walking, support for all the DER and JKS formats, and it’s fast. My bash script could spend a few minutes churning through a folder with certs and keys, my golang version does a few thousand in a second.
So I basically built a limited version of OpenSSL with better ergonomics and a lot of magic under the hood because you don’t have to specify input formats at all. I wasn’t constrained by things like backwards compatibility and interface stability, which let me make something much nicer to use.
I even was able to build a wasm version so it can run in the browser. All this from someone that is not a great coder. Don’t worry, I’m explicitly not rolling my own crypto.
The industry hasn't come up with a simple meme-format term to explain this workflow pattern yet, so people aren't excited about it. But don't worry, we'll surely have a bullshit term for it soon, and managers everywhere will be excited. In the meantime, we can just continue doing work with these new tools.
Operative word being “some”. The issue is that too many aren’t doing it that way.
> You dont just go “build thing”
Tell that to the overwhelming majority of posters discussing vibe coding, including on HN.
Thinking people who disagree with you hate you or hate the thing you like is a recipe for disaster. It's much better to not love or hate things like this, and instead just observe and come to useful, outcome-based conclusions.
* domain experts paying for tooling that will enhance their productivity
* capital/management class hoping to significantly replace domain experts
Software devs have been a famously tough market to sell tools to for a long time, so the better bet is B. Plus, the story on B is fantastic for fundraising; if there's a 10% chance that it checks out, you want some part of that as your capital portfolio.
I’ve been throwing codex at them and now they’ve all been rewritten in Go - cut down to about 10mb per process.
> We’ve verified that every AST produced by the Rust parser is identical to the C++ one, and all bytecode generated by the Rust compiler is identical to the C++ compiler’s output.
Is this a conventional goal? It seems like quite an achievement.
Porting a project from PHP7 to PHP8, you'd want the exact same SQL statements to be sent to the server for your test suite, or at least be able to explain the differences. Porting AngularJS to Vue, you'd want the same backend requests, etc..
No, they are quite terrible at doing that.
They may (I guess?) produce code that compiles, but they will, almost certainly not produce the appropriate combination of idioms and custom abstractions that may the code "at home" in the target language.
PS - Please fix your blockquote... HN ignores single linebreaks, so you have to either using pairs of them, or possibly go with italicization of the quoted text.
In my coding agent std::slop I've optimized for this workflow https://github.com/hsaliak/std_slop/blob/main/docs/mail_mode... basically the idea is that you are the 'maintainer' and you get bisect safe, git patches that you review (or ask a code reviewer skill or another agent to review). Any change re-rolls the whole stack. Git already supports such a flow and I added it to the agent. A simple markdown skill does not work because it 'forgets'. A 'github' based PR flow felt too externally dependent. This workflow is enforced by a 'patcher' skill, and once that's active, tools do not work unless they follow the enforced flow.
I think a lot of people are going to feel comfortable using agents this way rather than going full blast. I do all my development this way.
Would be curious to see more about how you save tokens with lua too.
Do you blog?
All my vibe coded projects are human directed, unless explicitly stated otherwise
And you might say that this is a hypothetical problem, one that is not practically occurring. Well, we had a similar problem like this in the recent past, that LLMs are close to _making actual_. When it comes to software patents, they were considered a _hypothetical_ problem (i.e. nobody is going to bother suing you unless you were so big that violating a patent was a near certainty). We were instructed (at pretty much all jobs), to never read patents, so that we cannot incriminate ourselves in the discovery process.
That is going to change soon (within a year). I have friend, whom I won't name, who is working on a project, using LLMs, to discover whether software (open source and proprietary) is likely to be violating a software patent from a patent database. And it is designed to be used, not by programmers, but by law firms, patent attorneys, etc. Even though it is not marketed this way, it is essentially a target acquisition system for use by patent trolls. It is hard for me to tell if this means that we will have to keep ignoring patents for that plausible deniability, or if this means that we will have to become hyper informed about all patents. I suppose, we can just subscribe to the patent-agent, and hope that it guides the other coding agents into avoiding the insertion of potentially infringing code.
(I also have a friend who built a system in 2020 that could translate between C++ and Python, and guarantee equivalent results, and code that looks human-written. This was a very impressive achievement, especially because of how it guarantees the equivalence (it did not require machine-learning nor GPUs, just CPUs and some classic algorithms from the 80s). The friend informs me that they are very disheartened to see that now any toddler with a credit card can mindlessly do something similar, invalidating around a decade of unpublished research. They tell me that it will remain unpublished, and if they could go back in time, they would spend that decade extracting as much surplus from society as possible, by hook or by crook (apparently they had the means and the opportunity, but lacked the motive); we should all learn from my friend's mistake. The only people who succeed are, sadly, perversely, those who brazenly and shamelessly steal -- and make no mistake, the AI companies are built on theft. When millionaires do it, they become billionaires -- when Aaron Swartz does it, he is sentenced to federal prison. I'm not quite a pessimist yet, but it really is saddening to watch my friend go from a passionate optimist to a cold nihilist.).
I don't know if it's a good fit. Not because they're writing a browser engine in Rust (good), but because Ladybird praises CPP/Swift currently and have no idea what the contributor's stance is.
At least contributing will be a lot nicer from my end, because my PR's to Ladybird have been bad due to having no CPP experience. I had no idea what I was doing.
Yeah that is the thing I struggle with. I am really happy for people falling in love with Rust. It is a amazing language when used for the right use case.
The problem is that had my Rust adventures a few years ago and I am over the hype cycle and able to see both the advantages and disadvantages. Plus being generally older and hopefully wiser I don't tie my identity towards any specific programming language that much.
So sometimes when some Junior dev discovers Rust and they get really obnoxious with their evangelicalism it can be very off putting. Really not sure how to solve it. It is good when people get excited about a language. It just can be very annoying for everyone else sometimes.
This rings very true, and I've actually disadvantaged myself somewhat here. I was involved in projects that made very dubious decisions to rewrite large systems in Rust. This caused me to actively stay away from the language, and stick to C++, investing lots of time in overcoming its shortcomings.
Now years later, I started with Rust in a new project. And I must say, I like the language, I really like the tools, and I like the ecosystem. On some dimension I wish I would have done this sooner (but on the other hand, I think I have a better justification of "why Rust" now).
I never fell in love with Rust or got particularly excited about adopting it. But, I just don't see a serious alternative (maybe Swift is fine for some cases but not in my field).
I believe Google's Rust journey was even more closely aligned with Ladybird: "we want memory safety, but with low impedance mismatch from C++". After like 5 years of trying to figure something like that out they seemed to go "OK actually fuck that we just have to use Rust and deal with the challenges it brings for a C++ shop".
Definitely isn’t one of those things that can be solved, but it’s helpful to be aware of and process on that basis. I think some personalities are likely disproportionately vulnerable to this behaviour, but I think it largely has a positive core of enthusiasm. It’s probably more a matter of those individuals growing in self awareness.
Perhaps we saw a big wave of that with rust because it meant a lot of things to a lot of different people, some more equip to express their enthusiasm with some self control than others.
And experience doesn't equal correct decision making. People just get traumatized in different ways.
Not anymore.
Next month it will be yet-another-language.
Eventually they come full circle and settle for either C or C++.
Not just volatility but also flip-flopping. Rust was explicitly a contender when they decided to go with Swift 18 months ago, and they've already done a 180 on it despite the language being more or less the same as it was.
Doesn't sound like it's some Fish-style, full migration to Rust of everything. Seems like they are just moving a couple parts over for evaluation, and then, going forward, making it an official project language that folks are free to use. They note that basically every browser already does that, so this isn't a huge shakeup.
> ... the entire port took about two weeks.
So he was ~halfway in when he made the Swift announcement.
if it works it works i guess, but it seems mad to me on the surface
I mean, they seem mostly to be against anything that isn't C++'s peculiar brand of Object Oriented Programming?
(also against women and immigrants, but that's a different story)
The Jakt -> Swift -> Rust pivots look like the same thing on a different level. The initial change to Swift was surely motivated by potential industry support gain (i believe it was a dubious choice from purely engineering standpoint).
It's awe-inspiring to see how a person can carve a job for himself, leverage hobbyists'/hackers' interest and contributions, attract industry attention and sponsors all while doing the thing he likes (assuming, browsers are his thing) in a controlling position.
Can't fully rationalize the feeling, but all of this makes me slightly wary. Doesn't make it less cool to observe from a side, though.
The truth is more simple: he's a good engineer and leader, people recognised that and offered him sponsorships, and the project took off by itself.
If I recall correctly, part of this was around classes they had that replaced parts of the STL, whereas the Swift C++ interop makes assumptions about things with certain standard names.
We’re at the point where a solid test suite and a high-quality agent can achieve impressive results in the hands of a competent coder. Yes, it will still screw up, needs careful human review and steering, etc, but there is a tangible productivity improvement. I don’t think it makes sense putting numbers on it, but for many tasks, it looks like there’s a tangible benefit.
Wary of what?
Long read on the topic (quite funny, covers Cluely): https://harpers.org/archive/2026/03/childs-play-sam-kriss-ai...
IIRC he used to work on the Safari browser engine at Apple.
LLM and rust rewrite together. And it does work so hopefully they get more attention and build it so I have an alternative browser to use
Correct me if I’m wrong since I don’t know these two languages, but like some other languages, doing things the idiomatic way could be dramatically different. Is “cleanup” doing a lot of heavy lifting here? Could that also mean another complete rewrite from scratch?
A startup switching languages after years of development is usually a big red flag. “We are rewriting it in X” posts always preceded “We are shutting down”. I wish them luck though!
Out of all the languages rust takes inspiration from, id rank C++ at the top of the list.
That's the biggest difference to C++ and most mainstream languages, you simply can't do OOP (which in my books is a good thing) and it forces you more towards traits and composition.
Startups are not a good comparison here. They have a different relationship with code than software projects.
Linux has rewriten entire stacks over and over again.
The PHP engine was rewritten completely at least twice.
The musl libc had entire components rewritten basically from scratch and later integrated.
If you do a rewrite you essentially put everything else on halt while rewriting.
If you keep doing feature dev on the old while another "tiger team" is doing the rewrite port then these two teams are essentially in a race against each other and the port will likely never catch up. (Depending on relative velocities)
Maybe they think that they can to this LLM assisted tools in a big bang approach quickly and then continue from there without spending too much time on it.
Moving Ladybird from C++ to a safer more modern language is a real differentiator vs other browsers, and will probably pay dividends. Doing it now is better than doing it once ladybird is fully established.
One last point about rewrites: you can look at any industry disruptor as essentially a team that did a from-scratch rewrite of their competitors and won because the rewrite was better.
What's different today really is the LLMs and coding agents. The reason to never rewrite in another language is that it requires you to stop everything else for months or even years. Stopping for two weeks is a lot less likely to kill your project.
Ladybird appears to have the discipline to have recognized this: “[Rust] is not becoming the main focus of the project. We will continue developing the engine in C++, and porting subsystems to Rust will be a sidetrack that runs for a long time.”
It's about Netscape. By the time, Netscape had dominated the browser market. It was the leader and that means they had all the market share to lose. You can bet Microsoft's decision makers were very closely monitoring what those at Netscape were doing.
Today, practically nobody uses Ladybird. No one even knows it[1]. It's so behind and has nothing to lose. If you really want to rewrite, it's better to do it when you have nothing to lose.
[0]: https://www.joelonsoftware.com/2000/04/06/things-you-should-...
[1]: to quote Joel, "no one" means less than one million people.
the hard bit (borrow checker) has still to be done...
Testing has become 10x as important as ever.
I am already using low code tooling with agents for some projects, in iPaaS products.
I have the opposite opinion. As LLM become ubiquitous and code generation becomes cheap, the choice of language becomes more important.
The problem with LLM for me is that it is now possible to write anything using only assembly. While technically possible, who can possibly read and understand the mountain of code that it is going to generate?
I use LLM at work in Python. It can, and will, easily use hacks upon hacks to get around things.
Thus I maintain that as code generation is cheap, it is more important to constraint that code generation.
All of this assume that you care even a tiny bit about what is happening in your code. If you don't, I suppose you can keep banging the LLM to fix that binary blob for you.
IMO Rust will strike a very strong balance here for LLMs.
I've been doing a few projects that are definitely outside my comfort zone with LLMs and its fine. I can read the code but I just don't have the muscle memory to produce it.
I see the opposite. New languages have more difficulty breaking into popularity due to lack of enough existing codename and ecosystems.
I feel like you just know it’s doomed. What this is saying is “I didn’t want to and cannot review the code it generated” asking models to find mistakes never works for me. It’ll find obvious patterns, a tendency towards security mistakes, but not deep logical errors.
The part that concerns me is whether this part will actually come in time or not:
> The Rust code intentionally mimics things like the C++ register allocation patterns so that the two compilers produce identical bytecode. Correctness is a close second. We know the result isn’t idiomatic Rust, and there’s a lot that can be simplified once we’re comfortable retiring the C++ pipeline. That cleanup will come in time.
Of course, it wouldn't be the first time Andreas delivered more than I expected :).
The tests many of us use for how capable a model or harness is is usually based around whether they can spot logical errors readily visible to humans.
No one wants to work with this generated, ugly, unidiomatic ball of Rust. Other than other people using AI. So you dependency AI grows and grows. It is a vicious trap.
I don't like this bit. Wouldn't it be better to decide on a memory-safe language, and then commit to it by writing all new code in Rust, or whatever. This looks like doing double the work.
I suspect that'll also be what happens here. And if the use of Rust is successful, then over time more components may switch over to Rust. But each component will only ever be in one language at a time.
The Ladybird devs painted themselves in a corner when choosing C++ for a new web browser, with many anti-Rust folks claiming that "modern C++ was safe". Well...
Thankfully Servo has picked up speed again and if one wants a Rust based browser engine what better choice than the one the language was built to enable?
it is totally possible to use some strict subset of C++, which will be memory safe.
Why was there ever any expectation for Swift having good platform support outside Apple? This should have been (and was to me) already obvious when they originally announced moving to Swift.
Apple puts zero resources into making that claim reality, however.
But in the end I can't help but feel Swift has become an absolute beast of a multi-paradigm language with even worse compile times than Rust or C++ for dubious ergonomics gains.
Have you actually used .NET on Linux/macOS? I have (both at home and work) and there isn't anything that made me think it was neglected on those platforms. Everything just works™
[1] Swift was first created in 2010, 16 years ago and officially launched in 2014, 12 years ago, by a huge multi-billion dollar corporation. The same corporation has launched hundreds of products and services in the same time period. If they really wanted Swift to be cross platform at a competitive level (Java, .Net, Python, JS, etc), they would have done it by now.
I wonder what kind of tech debt this brings and if the trade off will be worth whatever problems they were having with C++.
The problem was strictly how cpp is perceived as an unsafe language, and this problem rust does solve! Not being sarcastic, this truly looks like a mature take. Like, we don't know if moving to rust would improve quality or prevent vulnerabilities, here's our best effort to find out and ignore if the claim has merits for now. If the claim maintains, well, you're better prepared, if it doesn't, but the code holds similar qualities...what is the downside?
My general thoughts on Rust:
- Excellent for short-lived programs that transform input A to output B
- Clunky for long-lived programs that maintain large complex object graphs
- Really impressive ecosystem
- Toxic community
They're not porting the browser itself to Rust, for the record.
Don't forget that the Rust ecosystem around browsers is growing, Firefox already uses it for their CSS engine[0], AFAIK Chrome JPEG XL implementation is written in Rust.
So I don't see how this could be seen as a negative move, I don't think sharing libraries in C++ is as easy as in Rust.
“the Rust ecosystem around browsers is growing” – in the beginning pretty much 100% of the ecosystem around Rust was browser oriented
Thankfully Servo is picking up speed again and is a great project to help support with some donations etc: https://servo.org/
Seems like a lot of language switches in a short time frame. That'd make me super nervous working on such a project. There will be rough parts for every language and deciding seemingly on whims that 1 isn't good enough will burn a lot of time and resources.
I use AI more and more. Goes like create me classes A,B,C with such and such descriptive names, take this state machine / flowchart description to understand the flow and use this particular sets of helpers declared in modules XYZ
I then test the code and then go over and look at any un-optimal and other patterns I prefer not to have and asking to change those.
After couple of iterations code usually shines. I also cross check final results against various LLMs just in case
There is an open PR (by simonw btw): https://github.com/minimaxir/hacker-news-undocumented/pull/4...
> classic HackerNews title shortening algorithm
Adding the "with help from AI" almost always devolves the discussion from that to "developers must adopt AI or else!" on the one hand and "society is being destroyed by slop!" on the other, so as long as that's not happening I'm not complaining about the editorialized title.
Personally, I can’t get meaningful results unless I use the tool in a true pair-programming mode—watching it reason, plan, and execute step by step. The ability to clearly articulate exactly what you want, and how you want it done, is becoming a rare skill.
> Ralph Wiggum loop
Ladybird is much further ahead in terms of actually rendering web pages that people use.
The biggest advantage to Servo was that it is written in Rust. This move begins to nullify that advantage as well.
Why exactly does Servo make more sense?
I hope they both succeed. But Ladybird is more likely to become a usable browser first.
But Rust doesn't have C++ interop at all?
Firefox is a mixed C++ / Rust codebase with a relatively close coupling between Rust and C++ components in places (layout/dom/script are in C++ while style is in Rust, and a mix of WebRender (Rust) and Skia (C++) are used for rendering with C++ glue code)
Yeah but, you can do the same in Swift
It also doesn't have the disadvantages of Swift. Once the promise of Swift/C++ interop is gone there isn't enough left to recommend it.
[1]: https://www.swift.org/documentation/cxx-interop/
[2]: https://www.swift.org/blog/improving-usability-of-c-librarie...
Firefox solves this partly by not using `std` types.
For example, https://github.com/mozilla/thin-vec exists in large part because it's compatible with Firefox's existing C++ Vec/Array implementation (with the bonus that it's only 8 bytes on the stack compared to 24 for the std Vec).
I don't think this is the right response because certainly a meaningful discussion could've definitely taken place and given how they were already open to other languages which was the reason why they picked Swift in the first place.
I remember Andreas video where he talked about how people used rust in his codebase and they were so happy but later it became very difficult whereas they found with swift that it became easier to manage. That was the reason why they picked swift that time.
Certainly their goal wasn't to pick a popular language (because if that's what you want use python or JS) but rather a language that was relevant to what they were building.
So if D and Ada were relevant or not, that's the main point of discussion imo.
However, this is where d shines. D has a mature ecosystem. Offers first class cpp abi and provides memory safety guarantees, which the blog mentioned as a primary factor. And d is similar to cpp, low barrier for cpp devs to pick up.
But what I wanted to know was about evaluation with other languages, because Andreas has written complex software.
His insight might become enriching as to shortcomings or other issues which developers not that high up in the chain, may not have encountered.
Ultimately, that will only help others to understand how to write better software or think about scalability.
I agree that, this might be wrong behaviour and I don't think its any fault of rust itself which itself could be a blanket statement imo. There's nuance in both sides of discussions.
Coming to the main point, I feel like the real reason could be that rust is this sort of equilibra that the world has reached for, especially security related projects. Whether good or bad, this means that using rust would definitely lead to more contributor resources and the zeal of rustaceans can definitely be used as well and also third party libraries developed in rust although that itself is becoming a problem nowadays from what I hear from people in here who use rust sometimes (ie. too many dependencies)
Rust does seem to be good enough for this use case. I think the question could be on what D/Ada (Might I also add Nim/V/Odin) will add further to the project but I honestly agree that a fruitful discussion b/w other languages would've been certainly beneficial to the project (imo) and at the very least would've been very interesting to read personally
Attackers are surprisingly resilient to partial security.
While rust is nice on paper, writting complex software in it is mentally consuming. You can not do it for a long time.
Does this still get you most of the memory-safety benefits of using Rust vs C++?
The article fails to explain why. What problems (besides the obvious) have been found in which "memory-safe languages" can help. Do these problems actually explain the need of adding complexity to a project like this by adding another language?
I guess AI will be involved which, at this early point in the project would make ladybird a lot less interested (at least to me).
Why isn't that enough?
Well, what else is there besides the obvious? It's a browser.
So, even though they want the code base to be in Rust, they will continue writing new code in C++ and then translating it to Rust later to remove the C++ they just added.
There must be a really good reason for this, such as Rust doesn’t interop well with C++, otherwise this seems like a poor decision.
Yea, I'd bet it's that. Ideally, you'd want to stop writing C++ and continue with Rust on all new code, but Rust has stricter semantics, so the interop is somewhat "easy" in one direction, but very hairy in the other direction.
This means that in practice, you want to start porting from leaf components and slowly grow closer to the root, which stays in C++ for quite some time and just calls into Rust through C API (or something close to it).
If you're curious about the topic, there's a interop library called Zngur (https://hkalbasi.github.io/zngur/), which is built on this assumption. They have a pretty good explanation of the concrete problems on the homepage.
I am very interested to know if this time and energy spent actually improved memory safety.
Other engineers facing the same challenges want to know!
On the rust side, the question is how much `unsafe` they used (I would hope none at all, although they don't specify).
It seems like it is used mostly for FFI.
I am not trying to dunk on the effort; quite the contrary. I am eager to hear more about the goals it originally set out to achieve.
It could have been worse. C++ code naively converted line-by-line to Rust typically results in weird and unsafe Rust, but in this case it seems they've only been strict about the results being the same, not the structure of the implementation.
Rewrites have a very high risk of introducing regressions. Trying to fix bugs while rewriting will only make things harder, because instead of simply comparing outputs exactly, you'll have to judge which output is the right one. If you let the behavior significantly diverge during the rewrite, you'll just have two differently buggy codebases and no reference to follow.
It's much easier to make a bug-for-bug compatible copy, and fix bugs later.
This project, of all of them, throwing in the towel on AI makes me fear AI abstainers have no future.
they learn Rust
it takes a couple of years
it's not that hard.
I guess it's a long way off, since the LLM translation would need to be refactored into natural Rust first. But the value of it would be in that it's a real world project, and not a hypothetical "well, you could probably just...".
I'm confused about this part. What part of the browser did they want GC and inheritance for? I'd get it if they were writing the UI in this, but the rest of this post is about the JS engine. They weren't going to 1:1 map JS objects to Swift objects and rely on ARC to manage memory, were they?
You can model these with reference counting, but this turned out unfeasible in browsers. There's a great talk from when Blink (Chrome) transitioned from reference counting to GC, which provides a lot more details about these problems in practice: https://www.youtube.com/watch?v=_uxmEyd6uxo
> I'd get it if they were writing the UI in this, but the rest of this post is about the JS engine.
I think this might be the reason they started with the JS engine and not with some more fundamental browser structures. JS object model has these problems, too, but the engine has to solve them in more generic way. All JS objects can just be modeled as some JSObject class/struct where this is handled on the engine level.
DOM and other browser structures are different because the engine has to understand them, so the browser developers have to interact with the GC manually and if you watch the talk above, you'll see that it's quite involved to do even in C++, let alone in Rust, which puts a bunch of restrictions on top of that.
I watched some of his streams on the development of the JIT compiler (what this change set seems to replace) on one of his streams, and was blown away by the quality of Copilot generated suggestions/completions on an (under-represented) domain (x86 opcodes, etc). This was before Claude Code et al, and pretty early-on for LLM tooling.
The inevitable cleanup that will follow this could be done the same way. Refactoring like that can be done in more bite sized chunks, which makes it easier to review what is happening and control how it is done.
this entire project starts to look like "how am i feeling today?" rather than a serious project.
So far this is the first and only shift
EDIT: bramhaag pointed out the error of my ways. Thanks bramhaag!
i had high hopes for ladybird to become an alternative browser anyone with a working C++ compiler could build on whatever platform.
Given it's not launched and it's donor driven, I guess conserving developer time is a key priority? Dual track sucks lots of time?
I've translated it from Rust to V in 45 minutes. Works great:
https://github.com/medvednikov/libjs_v
Compiles in 0.2 seconds on my M5 (compared to Rust's 3.3 seconds).
Rust syntax is a PITA and investing a lot of effort in the language doesn’t seem worth the trouble for an experienced C++ developer, but with AI learning, porting and maintenance all become more accessible. It’s possible to integrate Rust in an existing codebase or write subparts of larger C++ projects in Rust where it makes sense.
I was recently involved in an AI porting effort, but using different languages and the results were fine. Validating and reviewing the code took longer than writing it.
> Porting LibJS
> Our first target was LibJS , Ladybird’s JavaScript engine. The lexer, parser, AST, and bytecode generator are relatively self-contained and have extensive test coverage through test262, which made them a natural starting point.
> Results
> The requirement from the start was byte-for-byte identical output from both pipelines. The result was about 25,000 lines of Rust, and the entire port took about two weeks. The same work would have taken me multiple months to do by hand.
How long until Ladybird begins to impact market dominance for Chrome and Firefox? My guess: Two years.
From what I can tell from HN, Brave seems to be popular with those users who hate Google but for whatever reason hate Mozilla even more, and I suspect those will be the most likely users to switch.
That's a lot of people contributing.
How many of them will be less willing to contribute in the future, and less productive when they do if a sizable portion is in Rust? Maybe there'll be more contributions and maybe there'll be less. I don't know. If you've managed to develop a community of 1200 developers who are willing to advance the project why upset the applecart?
Ah, but I see they actually haven't done that to most of their code, so maybe it's just a bit of pandering to the hype and fashion.
There is no evidence of that coming from this post. The work was highly directly by an extremely skilled engineer. As he points out, it was small chunks. What chunks and in what order were his decision.
Is AI re-writing those chunks much faster than he could. Yes. Very much so. Is it doing it better? Probably not. So, it is mostly just faster when you are very specific about what it should do. In other words, it is not a competitor. It is a tool.
And the entire thing was constrained by a massive test suite. AI did not write that. It does not even understand why those tests are the way they are.
This is a long way from "AI, write me a JavaScript engine".
Personally my sweet spot for LLM usage is for such tasks, and they can do a much better job unpacking the prompt and getting it done quickly.
In fact, there's a few codebases at my workplace that are quite shit, and I'm looking forward to make my proposal to refactor these. Prior to LLMs, I'm sure I'd have been laughed off, but now it's much more practical to achieve this.
In ~5 hours of prompting, coding, testing, tweaking, the STL outputs are 1:1 (having the original is essential for this) and it runs entirely locally once the browser has loaded.
I don’t pretend that I’m a frontend developer now but it’s the sort of thing that would have taken me at least days, probably longer if I took the time to learn how each piece worked/fitted together.
I imagine LLMs do help quite a bit for these language translation tasks though. Language translation (both human and programming) is one of the things they seem to be best at.
Helps me.
In the hands of experienced devs, AI increases coding speed with minimal impact to quality. That's your differentiator.
Would be as bad as being in a cult.
I'm no mind reader, and certainly no anthropologist, but I suspect that what separates humans from other (non extinct) animals, is that we compulsively seek caves that we can decorate with moving shadows and static symbols. We even found a series of prime numbers (sequences of dots, ". ... ..... .......") in a cave from the _ice age_. Mathematics before writing. We seek to project what we see with our mind's eye into the world itself, thereby making it communicable, shareable. Ever tell someone you had a dream, and they believed you? You just planted the seed for a cult, a shared cave. Even though you cannot photograph the dream, or offer any evidence that you can dream at all.
The industrial and scientific revolutions have distanced our consciousness from this idea, even as they enabled ever more perfect caves to manifest. Our vocabulary has become corrupted and unclear. We started using words like "reality", and "literally", and "truth", when we mean the exact opposite.
The conspiracy theorists and cultists, are just people who wandered into a new cave, with a different kind of fire, and differently curved walls, and they want to tell people from their old cave that they have found a way out of the cave into reality -- they do not yet realize (or do not want to accept), that they live in a network of caves, a network of different things in the same category.
During the early 2020s, we did a lot of talking about the disappearance of "consensus reality". This is scientific terminology mapped over the idea of caves and cults. You can tell, because the phrase is an oxymoron. It is not reality, if it requires consensus. It is fantasy, it is fiction, it is a dream. The cave has indeed become so widespread that we even _call_ it reality.
If you speak language, and read words, you are participating in a cult (we even call caves that had a kind of altar in the center a cult -- in Eurasia, there was a cave-cult called _the cult of the bear_, which had a bear skull placed in its center during the last ice age, and I would not be surprised if people spoke to it, with the help of hallucinogens). The only question is whether the cult is nourishing you or cannibalizing you.
To the person you are responding to (user ocd): your cave (ladybird, your hypothetical tv-series), no longer nourishes you like it once did. Maybe find a new cave, build a fire in it. Unlike a television series, you can fork a code base. You make it into the perfect cave, just for you. And if another person likes this cave, chooses to sit by the fire with you, well, now you have a cult.
Naturally this will be somewhat critical, but I need to first put things into context. I do believe that we really need an alternative to Google dominating our digital life. So I don't object that we need alternatives; whether Ladybird will be an alternative, or not, will be shown in the future. Most assuredly we need competition as otherwise the Google empire moves forward like Darth Vader and the empire (but nowhere near as cool as that; I find Google boring and lame. Even skynet in Terminator was more fun than Google. Google just annoys the heck out of me, but back to the topic of browsers).
So with that out of the way ... Ladybird is kind of ... erratic.
Some time ago, perhaps two months or three, Andreas suddenly announced "Swift WILL BE THE FOREVER FUTURE! C++ sucks!!!". People back then were scratching heads. It was not clear why Swift is suddenly our saviour.
Ok, now we learn - "wait ... swift is NOT the future, but RUST is!!!". Ok ... more head-scratching. We are having a deja-vu moment here... but it gets stranger:
"We previously explored Swift, but the C++ interop never quite got there, and platform support outside the Apple ecosystem was limited. Rust is a different story."
and then:
"I used Claude Code and Codex for the translation. This was human-directed, not autonomous code generation"
So ... the expertise will be with regards to ... relying on AI to autogenerate code in ... Rust.
I am not saying this is a 100% fail strategy, mind you. AI can generate useful code, we could see that. But I am beginning to have more and more doubts about the Ladybird project. Add to this the breakage of URLs that are used by thousands or million people world-wide (see the issues reported on the github tracker); or also the fact that, once you scale-up and more and more people use ladybird, will you be able to keep up with issue trackers? Will you ban more people?
In a way it is actually good that I am no longer allowed to make comments on their repository because I can now be a lot more critical and ask questions that the ladybird team will have to evaluate. Will ladybird blend? Will it succeed? Will it fail? Yes, it is way too early to make an evaluation, so we should evaluate in some months or so, perhaps end of this year. But I am pretty certain the criticism will increase, at the least the moment they decide to leave beta (or alpha or whatever model they use; they claimd they want a first working version in this year for Linux users, let's see whether that works).
God grant me the serenity
to accept the things I cannot change;
courage to change the things I can;
and wisdom to know the difference.
(courage to change the things I can;):- I think that this line must've given Andreas the strength, the passion to make the project reality.
but if AI made the change. Would the line be changed to courage to prompt an all powerful entity to change the things I asked it to.
Would that give courage? Would that inspire confidence in oneself?
I have personally made many projects with LLM's (honestly I must admit that I am a teenager and so I have been sort of using it from the start)
and personally, I feel like there are some points of curiosity that I can be prideful of in my projects but there is still a sense of emptiness and I think I am not the only one who observes it as such.
I think in the world of AI hype, it takes true courage & passion to write by hand.
Obviously one tries to argue that AI is the next bytecode but that is false because of the non deterministic nature of AI but even that being said, I think I personally feel as if the people who write assembly are definitely likely to be more passionate of their craft than Nodejs (and I would consider myself a nodejs guy and there's still passion but still)
Coding was definitely a form of art/expression/sense-of-meaning for Mr Andreas during a time of struggle. To automate that might strip him of the joy derived from stroking brush on an empty canvas.
Honestly, I really don't know about AI the more I think about it so I will not pretend that I know a thing/two about AI. This message is just my opinion in the moment. Opinions change with time but my opinion right now is that coding by hand definitely is more meaningful than not if the purpose of the project is to derive meaning.
The project's use of AI now echoes that - it's not being used to create new features, it's used for practical, boring drudge work of translating between two languages. So still very much on brand.
They ported an existing project from CPP to Rust using AI because the porting would've been too tedious. I don't think they're planning on vibe coding PRs the way you're imagining.
I'm not sure how I'd feel if I woke up and found a system I worked on had been translated into an another language I'm not neccessarily familiar with. And I'm not sure I'd want to fix an non-idiomatic "mess" just because it's been translated into a language I'm familiar with either (although I suspect they'll have no problem attracting rust developers).