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Comment by 46Bit | Hacker News Reader

You have a point. I've done medium-sized C projects in my degree, but my professional background is mostly web.

I've been using Rust heavily for 10 months. I think that if you want to use it for web stuff you very much can, but the language is more immature than it might first appear. If the community keeps going the way it is, I hope to work with it commercially by 2020.

The most promising things I've read about it as a serious systems language are from Cambridge Consultants [1,2], but there's a lot of ongoing work to make it ready for embedded work.

[1] http://blog.cambridgeconsultants.com/wireless-product-develo...

[2] http://blog.cambridgeconsultants.com/wireless-product-develo...

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Why use Rust for web development? There are very few web back ends in the world that need the speed of C++ or Rust.

Java, C#, Go, Haskell, OCaml are much easier to ramp people up with and hire for.

If rust ever gets to the point where it's not much harder to write than java/c# then why not got for the fastest one and avoid performance death by a thousand cuts? A millisecond here and there can add up.

And then there's the environmental cost of slower code. How many tonnes of CO2 emissions are higher level languages responsible for daily?

> If rust ever gets to the point where it's not much harder to write than java/c# then why not got for the fastest one and avoid performance death by a thousand cuts?

Sure. If it's just as easy for the task then why not?

But I wouldn't recommend Rust for web development for the same reason I wouldn't recommend C++ for web dev: complexity. Obviously, this is entirely subjective but I don't think either language will ever be easier to write than Java or C#, especially for beginners.

I used to TA a freshman data structures class. I can't imagine ever going to a class of new programmers and trying to explain to them when to use Rc<RefCell<Vec<T>>> vs. Rc<Vec<RefCell<T>>>.

I'm not saying this makes Rust as easy as Java or C#, but I don't think `Rc`/`RefCell` types are the cause, nor for that matter the solution to the cause.

Idiomatic Rust makes single-threaded interior mutability very, very rare. I don't remember ever once encountering the dilemma of "Vec<RefCell<T>> vs RefCell<Vec<T>>", in my own code or elsewhere.

In fact, my current project (https://github.com/team-worm/spice) involves an HTTP server written in Rust. Like you suggest, managing state across requests was one of the harder parts (both for myself to work out fully and for a team member who started with no Rust experience to grasp).

However, much of that difficulty was intrinsic to the problem- the HTTP library we use is multithreaded, so for correctness we have to synchronize access to the state. Instead of discovering this by way of race conditions or hard-earned experience, Rust enforces it for us. Team members who have never used Rust before can be trusted to go in and work on the server without worrying about causing subtle concurrency bugs. They hit the brick wall of error messages instead.

> I used to TA a freshman data structures class. I can't imagine ever going to a class of new programmers and trying to explain to them when to use Rc<RefCell<Vec<T>>> vs. Rc<Vec<RefCell<T>>>.

I'm interested - how do you teach it? I would have thought that the type system could make these things easier to visualise rather than harder, but then I don't have teaching experience.

A friend pointed out some reasons, in particularly the safety stuff, that would make Rust unsuitable.

:-) I've been trying to keep the nuance in my comments here. When I said, "I think that if you want to use it for web stuff you very much can," I'd emphasise the, "if you want to."

At the moment a lot of hobbyists are doing web stuff in Rust. Commercially I think usage would be in the same vein as the common pattern of rewriting Ruby services in Go if it starts to limit performance.

Rust is also pretty attractive for use in AWS Lambda and Google Cloud Functions. It's ability to strictly control memory usage and make the most of CPU resources is really powerful in an environment where you're billed based on memory and CPU time.

If you've got a particularly hot lambda function, rewriting it in Rust is a pretty simple way to save a bunch of money.

Exactly. Sneak some Rust code into your business-critical systems for that extra job security! :)

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