Rust: A quest for performant, reliable software [video]

5 months ago (youtube.com)

Slides: https://docs.google.com/presentation/d/1SoDsm_m_pb_gS6Y98Hgh...

The most interesting slide IMO:

  The diaspora

  Mozilla laid off much of the Rust team in August 2020
    - Hacker News discussion https://news.ycombinator.com/item?id=24143819
  ~everybody landed at a big tech company
  Result: Rust knowledge well distributed around industry
  No one company dominates
    - In contrast to Java, Swift, Go, C#, Dart
  Strong sense of collaboration & common mission
    - You can really feel this at conferences

  • Regarding Go, does Google actually "dominates“? Google has a team for the development of the language but does that mean it dominates?

Nice! I've wanted to give a similar talk. My thesis is that Rust won on usability above all else. If you look at the semantics of Rust, it's essentially an ML style language with typeclasses and linear types. In some alternate history that's a PhD thesis by someone at Inria that exactly 4 people use. But by making the language actually usable with good errors, familiar syntax (yes, syntax matters!), and documentation, Rust got users. I don't want to get into an in depth comparison but if you look at the documentation of even the most popular functional languages, it's not even close. And they've had a head start of decades!

  • To be clear: Rust does not have linear types. Rust has affine types. An affine Goose can't destroyed more than once. However zero isn't more than one. A linear Goose must be destroyed exactly once. Austral would be an example of a language with linear types.

    In C++ if we destroy this Goose twice, probably everything catches on fire, whoops.

    In Rust or Austral if we attempt to destroy this Goose twice the code doesn't compile. No executable for you until you stop destroying the Goose twice.

    In C++ or Rust if we forget to destroy the Goose, the Goose-destroying code never runs. Hope that wasn't important.

    In Austral if we forget to destroy the Goose, the code doesn't compile. No executable for you until you ensure the Goose is destroyed.

    • I agree with you, but noting that "forgetting to destroy the Goose" is not done by not explicitly destroying it (in both C++ and Rust), rather by explicitly not destroying it (or other edge cases, such as `Rc` cycles).

  • Rust has a combo: people come for safety, stay for usability.

    Languages struggle to win on usability alone, because outside of passion projects it's really hard to justify a rewrite of working software to get the same product, only with neater code.

    But if the software also has a significant risk of being exploited, or is chronically unstable, or it's slow and making it multi-core risks making it unstable, then Rust has a stronger selling point. Management won't sign off a rewrite because sum types are so cool, but may sign off an investment into making their product faster and safer.

    • Generally speaking I was more prone to agreeing with Rust-haters, and thought the whole idea of how Rust lifetimes are implemented is flawed, and the borrow checker is needlessly restrictive. I also disagree with some other ideas like the overreliance on generics to do static dispatch leading to large executables and slow compiles.

      To be clear I still think these criticisms are valid. However after using the language in production, I've come to realize these problems in practice are manageable. The langauge is nice, decently well supported, has a relatively rich ecosystem.

      Every programming language/ecosystem is flawed in some way, and I think as an experienced dev you learn to deal with this.

      It having an actual functioning npm-like package management and build system makes making multiplatform software trivial. Which is something about C++ that kills my desire to deal with that language on a voluntary basis.

      The ecosystem is full of people who try to do their best and produce efficient code, and try to understand the underlying problem and the machine. It feels like it still has a culture of technical excellence, while most libraries seem to be also well organized and documented.

      This is in contrast to JS people, who often try to throw together something as fast as possible, and then market the shit out of it to win internet points, or Java/C# people who overcomplicate and obfuscate code by sticking to these weird OOP design pattern principles where every solution needs to be smeared across 5 classes and design patterns.

  • Not sure if I would follow that point about usability. For me usability means also how usable it is to new people. How usable is the language to a foreign person compared to e.g. Python, Go or even Java - or if you want to mention functional languages like F#?

    But besides that I am totally on your side, usability is great.

  • Couldn't agree more about the syntax. It may be "ugly" but it's just so much easier to mentally parse than ML-style syntax.

Here's an amusing anti-Rust talk: "Rust a language without poetry".[1] It's a reasonable critique, but the presentation is awful. It seems that someone took a paper and ran it through some AI program that provided text to speech and irrelevant images. Need to run it through a tool to extract the text, then discard the video.

"Every (lost) week spent refactoring to satisfy lifetime constraints..." Not wrong.

[1] https://www.youtube.com/watch?v=kLXXZddWCJU

  • That was amusing. It felt like those AI ads that YouTube sometimes feeds me, where a perpetual preamble promises to have a point and to get to it, which might have something to do with toe fungus or restoring virility but you’ll never know because the actual point is to lull you into a trance-like state of perfect thoughtlessness.

> "How Rust Won"

I love Rust, I'm a fan of writing it and I love the tooling. And I love to see it's (hopefully) getting more popular. Despite this, I'm not sure if "won" is the right word because to my very uneducated eyes there is still considerable amount of Rust not succeeding. Admittedly I don't write so much Rust (I should do more!) but when I do it always baffles me how tons of the libraries recommended online are ghost town. There are some really useful Rust libraries out there that weren't maintained for many years. It still feels like Rust ecosystem is not quite there to be called a "successful" language. Am I wrong? This is really not a criticism of Rust per se, I'm curious about the answer myself. I want to dedicate so much more time and resources on Rust, but I'm worries 5 to 10 years from now everything will be unmaintained. E.g. Haskell had a much more vibrant community before Rust came and decent amount of Haskellers moved to Rust.

  • I don't even write in Rust, yet I'm curious if those libraries you talk about are truly in "abandoned" state and not simply in "done" state? Some languages somehow managed to build thriving ecosystems of libraries where they don't require constant attention and perpetual churn like in JS and Python. I see it too often e.g., in Clojure, where lib authors even have to add "maintenance disclaimers" noting that the lib is good for what it was designed for and there are no plans to add new features and no known bugs or critical dependencies found, and the lib is not abandoned, and they update those notes periodically, just for the sake of showing any git activity.

    • No, many are truly abandoned.

      I have this all the time. Any new rust project and you have to wade through a bunch of once-great crates.

      But that's because rust is new. The initial surge over produced solutions to, say binary serialization, and under produced, say, good geodesy libraries. And many many were abandoned. Go to any of the "are we X yet" sites and you'll see many crates that are clearly not finished or advancing which were recently considered SoA.

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    • Any library in Rust comes with Cargo.toml file listing dependencies and their versions. Rust build system allows to use later versions of the libraries so presumably an application that uses an old library will have dependencies for the library updated.

      The problem is that sometimes library may need to pin a dependency version. Or a dependency was released with a newer major version update and do not back-port security fixes to older versions.

      So one cannot just use an old library. Its dependency list must carefully considered.

      Now this problem exists with any package management system. But in Rust it is more visible as the language still evolves quickly with non-trivial new features released often.

      Then the library authors may want to use newer language features on their API. Then they simply bump the library mayor version and maintain only that. So an old dependencies will not get updates.

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    • > I see it too often e.g., in Clojure, where lib authors even have to add "maintenance disclaimers"

      I think this is a peculiarity of Clojure. Clojure is optimized for simplicity and as the saying goes: "It seems that perfection is attained not when there is nothing more to add, but when there is nothing more to remove."

      I don't use Clojure these days. Maybe I should revisit the language. It has some really nice ideas.

  • It's such a surprising dichotomy! Rust tooling, language and low-level capability makes it my top choice in several domains. It strikes me as the best tool available in high-performance and low-level domains. I contrast this with your observation: most of the open-source software (libraries generally) I see in rust are of poor quality.

    I'm building a structural biology ecosystem in rust, split out into several libs, and a GUI program. Molecular dynamics, file format interop, API interaction, 3D viewer/dashboard/manipulation etc. I also do embedded in rust for work and personal projects. In both of these domains (High-performance scientific programming/GUI+3D, and embedded), I have had to write my own tooling. Nascent tools exist, but they are of too poor quality to use; e.g. easier to rewrite than attempt to work around the limitations of.

    I'm at a loss. When I talk to people online about embedded rust, I find people discussing design patterns I think are high-friction (Async and typestates), and few people describe projects.

    I think part of the problem is that it has acquired a group of people who design APIs and write libs without applying these libs to practical problems, which would expose their shortcomings.

    • I can agree to an extent that API designers sometimes (often?) over engineer for imagined problems.

      At the same time, I've been working on an embedded Rust project and trying Embassy for the first time and it is _amazing_.

      First of all I've had good logging and debug support with probe-rs. Secondly, being able to do ergonomic DMA transfers with async/await syntax feels like cheating. The core goes to sleep until your transfer finishes and an interrupt fires which wakes up the core and continues your async state machine, which the compiler built for you from your async code.

      Distinct tasks can be split up into separate async functions, the type system models ownership of singleton hardware well (you can't use Pin 8 for your SPI bus there, you already "moved" it to your I2S peripheral over there!), and it all comes together with pretty minimal RAM usage, efficient use of the hardware, and low power consumption if you're mostly waiting on data transfers.

      I'd be happy to talk more about practical problems if you want to get specific.

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    • You're last quote hits the nail on the head. I've found that good libraries are written by people actually solving the problem and then open sourcing it. pytorch, numpy, eigen, ros, openssl, etc. these all came from being trying to actually solve specific problems.

      I think rust will get those libraries, but it takes time. Rust is still young compared to languages with a large amount of useful libraries. The boost project in c++ started in the 90s for example. It just takes time.

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    • PDF handling came to mind as absolutely horrible experience. If you want to make a pdf, the choices were either: 1. Very low level, getting into the nitty gritty implementation details of PDF. 2. Very High level, only suitable to make the equivalent of a word document with very little control of layout 3. Typst, which is nice externally but honestly very difficult to use as a library. 4. mupdf over C FFI can get you mid-level pdf generation. Mid level as in you control layout but aren't using an editor to inspect the generated raw instructions in a PDF. Then you have unsafe everywhere or time spent with FFI making basic wrapper/abstraction negates the benefits.

      Oh and for the first 3 the relevant docs for using it in this way are out of date and you will need to look at source code.

  • I think you can say Rust won. There's enough investment from big tech and enough demonstrated value that it won't go away. And compared to functional languages with similarly sophisticated type systems? Rust has gained more users in the past 10 years than probably all of those other languages combined. That's not a fluke. Rust has pulled off making functional programming mainstream

  • By any standard of language development rust "won" in that a decade after creation it has a thriving ecosystem and companies using it exclusively. The White House named it by name.

    I would say it won like it won the lottery, not like it won the tournament.

    • I'm not sure how a programming language can win other than having a thriving ecosystem and seeing use, as you point out. The current USA government removed the “Back to the Building Blocks: A Path Toward Secure and Measurable Software.” report and fired the people responsible though. So for all we know the current White House might be betting on PHP.

      As professional developers, however, I think there is also the job market to consider. It obviously depends on where you live in the world, but in my area there have been 0 Rust jobs for 5 years. There are plenty of C++ jobs, there are even a few Zig jobs once in a while. Go on the other hand has seen an explosive growth, though probably as a replacement for C# and Java rather than for C++.

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  • I've been writing Rust professionally for 3+ years and, to me, Rust has won.

    These days I write almost everything in Rust and there are only two outlier situations;

    - Environments where I can't use Rust effectively. Web (wasm is great but it's not there yet), Apple, Cloudflare workers/Cloudfront edge functions.

    - Use cases where there aren't good tools for Rust (like web scraping, pdf manipulation, that sort of thing)

  • I personally would love to see a heavily moderated, curated, security hardened crates repository as an alternative to crates.io that contains only well-maintained, security audited, organizationally vetted crates.

    For organizations that have regulatory, safety, strong security etc concerns (a market Rust is a natural fit for) this could be critically important. But even more so I would just use it. I am tired of my `cargo tree` rapidly turning into an exploding maze. I don't want 3 different MD5 or rand or cryptography or http packages used in one static linkage, and I don't want them bringing in an exploding maze of transitive dependencies of their own.

  • I feel like Rust hasn't won yet - it needs to transition from the cool technology people because of the hype, novelty and the clout it affords them to the pragmatic boring technology people use because it's the best tool for the job.

    In this stage, the unique standout features are given a lot of limelight, and people are a bit more forgiving with usability failings and library shortcomings, as that can be fixed later.

    If they fail, they'll be relegated to the 'perpetually misunderstood' pile, like Haskell has.

    Node/Ts has made the transition a while ago, Go's ride was a bit more bumpy (most ppl agree the language is good, but channels are a bit of an acquired taste).

    I think Rust is in the process of making the jump. I think language devs and library maintainers are a bit more responsive to the borrow checker usability gripes (rather than the knee-jerk 'you just don't get it' reaction) and the ecosystem expands in both depth and breadth. Imo the question of Rust making it is more of a 'when' than 'if', but it's not there yet.

  • It's quite the opposite. The number of high-quality maintained libraries is growing.

    Rust keeps growing exponentially, but by Sturgeon's law for every one surviving library you're always going to have 9 crap projects that aren't going to make it. Unfortunately, crates.io sorts by keyword relevance, not by quality or freshness of the library, so whatever you search for, you're going to see 90% of crap.

    There was always a chunk of libraries destined for the dustbin, but it wasn't obvious in the early days when all Rust libraries were new. But now Rust has survived long enough to outlive waves of early adopter libraries, and grow pile of obviously dead libraries. The ecosystem is so large that the old part is large too.

    https://lib.rs/stats#crate-time-in-dev

    Rust is now mainstream, so it's not a dozen libraries made by dedicated early adopters any more. People learning Rust publish their hello world toys, class assignments, their first voxel renderer they call a game engine. Startups drop dozens of libraries for their "ecosystem". Rust also lived through the peak of the cryptocurrency hype, so all these moon-going coins, smart contract VMs and NFTs exchanges now have a graveyard on crates.io.

    When you run into dead libraries in Python or Java you don't think these languages are dying, it's just the particular libraries that didn't make it. JavaScript has fads and mass extinctions, and keeps going strong. Rust is old enough that it too has dead libraries, and big enough that it has both a large collection of decade-old libraries, as well as fads and fashions that come and go.

  • I agree with the sentiment somewhat. Some rust libraries are dying, while some great new ones thrive (recently found iroh and wgpu to name a few). Everyone wants to write a game engine or some fun project and then abandon it, but no one wants to write a game. No application software has really "cemented" itself in the global ecosystem. Except for maybe ripgrep?

    I would like to see support for more compilers (https://rust-gcc.github.io/), more interoperability with C/C++, better support for cross-compilation. Maybe less reliance on crates.io, static linking, and permissive licenses.

    Still, I see Rust as the natural progression from C++. It has enough momentum to flatten all competitors (Carbon, Zig, Nim, Go) except scripting languages

    • > Still, I see Rust as the natural progression from C++

      I don't; Rust has its niche but currently can't replace C++ everywhere.

      From what I'm aware of, Rust has poor ergonomics for programs that have non-hierarchical ownership model (ie. not representable by trees), for example retained mode GUIs, game engines, intrusive lists in general, non-owning pointers of subobjects part of the same forever-lived singleton, etc.

      > Go

      To displace Go you must also displace Kubernetes and its ecosystem (unlikely, k8s is such a convenient tool), or have k8s move away from Go (not gonna happen considering who developed both)

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    • Rust will not "flatten" Go. They have some overlap but generally don't serve the same purpose and don't appeal to the same crowd. Go's popularity is undeniable, both in open source and in the industry. Outside of major shops and the odd shady Fintech startup, there are still very little Rust jobs out there. It's not necessarily bad, it's just the nature of it. Rust adoption is a slow thing because it addresses problems faced by slow moving software.

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    • I find a lot of Rust libraries "seem" dead, based on github activity, but looking into it, they are actively used in many projects. I think Rust projects just tend to have less open issues, and don't need to be maintained as often. This is also the case internally at my company.

  • Also there is a certain npm feeling, every time I try out some trendy project, endless list of crates being compiled, even more interesting is seeing some being compiled multiple times.

    • I agree it is a problem. Though in my experience it's still not as bad as NPM. I still know what most of the dependencies do, even when there are hundreds. And you usually get hundreds of dependencies only for things that simply do a lot. E.g. one of my projects has hundreds of dependencies but that's because it includes wasmtime, which feels fairly justified.

      In NPM you often get thousands of dependencies for things that should be simple like Vue.

      Another factor is that projects are often split into many crates for compile time & modularity reasons, e.g. Gix is dozens of crates.

      The "two versions of a crate" is actually a great thing. In other ecosystems like Python you would be simply unable to build the project at all because you can only have one version of any dependency.

      The one thing that I think is a big problem is where you have splits in the ecosystem, e.g. anyhow vs snafu, or Tokio Vs Smol. Once your project gets to a certain size you end up including every vaguely popular error handling crate. I think that's one of the big downsides of a small standard library which I haven't heard anyone mention.

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  • The talk touches on this notion specifically. The author notes that it's intentionally clickbait.

  • I would guess the intent is that it won the argument. In 2015 if you'd asked WG21 why you can't have this model of safety for C++ you'd be told it's a pipe dream and they only standardize things which can be realised.

    Because we won the argument now that doesn't work. When you say "it's a pipe dream" you're either ignorant or a liar, so, in 2025 WG21 didn't say this can't be realised - when they were shown proposals to do exactly this - they said well, we think we can achieve the same goals via a different route which suits us better, we just need more time.

    Whether you believe that or not is a different conversation, but Rust won the argument.

I’m glad not completely off with my bet 5 years ago that Rust will get larger chunk of the market. With the spread of AI Rust feels like a good candidate among Typescript and Python giants in a an era of coding assistant tools that needs a good nudge like Rust compiler.

  • As a counterpoint, Rust is one of the languages that AI is worst at writing - currently, at least.

    Perhaps there could be a future where the compiler/checker will be able to integrate more closely with whichever agent is attempting to write Rust - more closely than the current paradigm, where a hapless Claude repeatedly bashes its head into the borrow checker to no avail.

    • I think I disagree with this sentiment. I’ve found AI to be poor at one-shotting rust but give it a short agentic loop running `cargo check` and it can often produce code more solid than that created with a dynamically typed language.

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    • > Rust is one of the languages that AI is worst at writing - currently, at least

      Everyone makes similar statements about AI, Ai is currently bad at this or that. I find it quite good to write Rust. Can you give a concrete example of what AI failed to write for you

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I once read an interview with Guido van Rossum where he was asked what the point in time was when he realized that Python took off. He said, never, it just slowly but continuously grew.

This stuck with me. I hope we can say the same thing about Rust 10, 20 or 30 years from now.

  • Python was my first language and that is precisely how it felt. I would be at a convention or conference and mention python and it seemed like people didn't care, had a negative opinion or just didn't use it. It was treated as something only semi-programmers did, like people whose job wasn't actually programming, business analysts or scientists.

    Then one day python was suddenly top of the charts, probably post python 3 (old timers hated it but it really improved ergonomics) but not immediately so. Rather later on when they fixed the performance loss from 2->3 (which looking back as a primarily Rust coder now, was a hilarious argument that community had internally because even my worst, most quickly cobbled together rust code beats some of my best python code at the same task performance wise).

I was wondering where I recognized your name before, before I realized you're the linebender guy.

Hello! Big fan of your UI research