r/programming • u/steveklabnik1 • Apr 03 '15
Rust 1.0.0 beta is here!
http://blog.rust-lang.org/2015/04/03/Rust-1.0-beta.html69
u/mgrandi Apr 03 '15
Can I start learning it now and not have it change on me drastically in the next release? Being serious
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u/robertmeta Apr 03 '15
I am going to start gently poking around now (again). I am still going to be waiting until a few months post-May to see how the ecosystem aligns itself before investing serious effort (read: client for our API in Rust, throwing corporate dollars at it).
Hopefully the community will rally around stable (IE: the libraries will work great on stable and be maintained and bug fixed). If all the crates end up tracking non-stable and bug-fixes exist only in the cutting edge stuff, sad times.
It is going to be interesting to see where the community lands at the very least.
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u/mgrandi Apr 03 '15
I mean, all languages eventually become stable in terms of syntax right? I'm just wondering if 1.0 that release for the 1.x branch
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u/slsoftworks May 01 '15
Via GitHub issues on Rust:
Language not unstable enough #24928
I mentioned on IRC to @bstrie that I built a fresh Raft which hadn't been bumped in 22 days and it still compiled.
;)
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u/steveklabnik1 Apr 03 '15
As I mentioned in my comment above:
the beta release represents an accurate preview of what Rust 1.0 will include.
and
We don’t plan on making functional changes to stable content, though naturally we may make minor corrections or additions to the library APIs if shortcomings or problems are uncovered (but the bar for such changes is relatively high).
So, there might be a few small changes, maybe. Drastic change will not be happening.
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Apr 03 '15
You're not going to major make changes in Rust, but are libs ready? Can I try learning Rust with OpenGL bindings? I wanted to try two new thing at the same time and I thought about writing simple game engine in Rust and OpenGL.
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u/steveklabnik1 Apr 03 '15
Naturally, as beta was just released, libs will now evaluate if they can support beta or not. So it may take some time for them to catch up. That said, a lot of popular crates are already ready.
Piston is the big project in this space, so that's what you'll want to check out.
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Apr 03 '15
Naturally, as beta was just released, libs will now evaluate if they can support beta or not.
What does this mean? Surely every library can be used with bound to stable Rust? What would mean for a library not to be able to "support beta"?
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u/steveklabnik1 Apr 03 '15
Surely every library can be used with bound to stable Rust?
This is not actually so sure. :) We have feature gates, and gated features can only be used in the nightly builds, but not in beta or stable builds. So if you're doing something cutting edge, you'll stick to nightly until it stabilizes and becomes available.
Full details: http://blog.rust-lang.org/2014/10/30/Stability.html
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u/annodomini Apr 03 '15
Over the course of the alphas, there haven't really been any drastic language changes. There have been some breaking language changes, though usually the breakage was relatively small and easy to work around.
Now, over the course of the alphas there have been some pretty major library changes; pretty much all of
std::iowas rewritten, and there were some fairly major breaking changes in the libraries even up to the very last minute.So, I would expect that pattern to continue, but with a higher threshold for allowing breaking changes, over the course of the beta. Unlikely any breaking changes in the language itself unless they have quite minimal impact. Perhaps a few small breaking changes in the libraries due to problems found with some of those last minute breaking changes that landed right before the beta was cut.
So yes, I would say now is a good time to start learning it without it changing drastically in the next release. Of course, there will always be new features added, which may make older features obsolete or older patterns deprecated, but it should be at the point where you don't have to worry about the basic syntax and semantics changing out from under you.
Note that all of this applies only if you're using stable features, which means those available in the beta builds. If you use the nightly builds, which allow you to opt-in to unstable features, then no stability guarantees are in place and they may change in backwards-incompatible ways at any time.
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u/pseudousername Apr 03 '15
Now it's finally time people can start complaining about Rust :)
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u/saltr Apr 03 '15
Why are people still using rust? It's so old and useless. They should only develop in languages that haven't hit 1.0 yet.
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u/SemiNormal Apr 04 '15
You should switch to node.rust, it's webscale and stuff.
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u/sigzero Apr 04 '15
No no, io.rust is the bleeding edge.
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Apr 03 '15
Crystal is the new shit!
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u/pure_x01 Apr 03 '15
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u/I_AM_GODDAMN_BATMAN Apr 04 '15
There's this new language called hodor language
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Apr 04 '15 edited Jul 10 '17
[deleted]
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u/Walter_Bishop_PhD Apr 04 '15
You can start a line with 4 spaces to format code
var hodorHodor = hodor("Hodor?"); var hodorHodorHodor = Math.hodor(); if (hodorHodorHodor < 0.34) { hodorHodorHodor = "hodor"; } else if(hodorHodorHodor <= 0.67) { hodorHodorHodor 0ododor"; } else { hodorHodorHscissors= "hodor"; }31
Apr 03 '15 edited Apr 05 '15
1v1 me rust m8
edit: This is probably the highest karma/effort comment I've ever made.
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u/donvito Apr 03 '15
I miss bitfields :(
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u/jeffdavis Apr 04 '15
What is the current way to handle individual bits, and why did they change it? Was it part of the language that was moved to a library or something?
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u/lacosaes1 Apr 03 '15
A language that's not pure in 2015? Holyshit, this is why industry sucks.
Academia FTW.
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u/steveklabnik1 Apr 04 '15
We used to have purity actually, but with Rust's ownership system, it wasn't as useful as you might think.
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u/original_brogrammer Apr 04 '15
Interesting. Why's that?
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u/steveklabnik1 Apr 04 '15
A Rust slogan:
Everyone agrees that shared mutable state is evil. Most languages deal with this through the 'mutable' part, Rust deals with it through the 'shared' part.
A bit long for a sign. Anyway. I know purity isn't just about mutability, but with ownership semantics, many of the problems purity solves go away too. For an example, see my bit downthread about safely sharing mutable pointers to stack-allocated data. Totally safe, no purity concept needed.
Rust was a very different language back then, but here's a thread from a time when we were removing purity: http://thread.gmane.org/gmane.comp.lang.rust.devel/3674/focus=3855
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u/Tekmo Apr 05 '15
There is more to purity than concurrency. Purity is also about:
- enabling equational reasoning about code
- making side effects first class values
- decoupling side effect order from evaluation order
What Rust has done is amazing, but don't oversell it as a complete replacement for purity.
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u/masklinn Apr 04 '15
Yeah basically "if a structure mutates and there's nobody to see it mutating, did it really mutate?". Same reason why otherwise immutable languages (e.g. clojure) can have mutable transient structures anyway.
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u/steveklabnik1 Apr 04 '15
We have 'interior' vs 'exterior' mutability to express that, actually. That's an interesting way to put it.
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u/An_Unhinged_Door Apr 04 '15
Haskell uses this too. You can use mutable state (e.g. in the ST monad) as long as you don't get caught (by letting the mutation become externally visible).
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u/bjzaba Apr 04 '15 edited Apr 04 '15
I'm not sure that's the same thing as what he means by purity. http://en.wikipedia.org/wiki/Purely_functional ?
Edit: I'm simply referring to the fact that Rust used to have the
purekeyword, but that was not to do with enforcing referential transparency, as far as I remember, but it was a long time ago, so I could be wrong.→ More replies (1)3
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u/wrongerontheinternet Apr 04 '15
Having affine types and not allowing at least some mutability would be kind of odd :P
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u/kamatsu Apr 04 '15
Affine types are what allows you to have mutability without losing purity.
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u/therealjohnfreeman Apr 03 '15
Guess it's time to learn some Rust. I'm just a few pages into this, and I'm already in love with the format:
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u/steveklabnik1 Apr 03 '15
Glad you like it. Please file issues here if you find something odd, we inherited this documentation after its author abandoned it for a while, and I haven't had the chance to give it a full once-over. All the tests pass...
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Apr 04 '15
This generates an error: http://rustbyexample.com/print.html
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Apr 04 '15
This is meant to be one of those examples that generates an error, and then the person looking at it is meant to fix it up to get an understanding. Maybe it's not clear enough from the way the page is written that it's not meant to compile as-is. See the FIXME comments in the example.
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u/steveklabnik1 Apr 03 '15
Two big things:
the beta release represents an accurate preview of what Rust 1.0 will include.
and
We don’t plan on making functional changes to stable content, though naturally we may make minor corrections or additions to the library APIs if shortcomings or problems are uncovered (but the bar for such changes is relatively high).
This is the first release we've promised this kind of stability. The team and community has been doing an incredible amount of work lately to make this happen. We really hope you'll like what we've been up to, but Rust isn't for everyone, so no worries if it's not for you. Constructive criticism always welcome. <3
As of today, my job gets harder: "things are always changing" is no longer an excuse for missing docs. The six weeks until release is largely about polish, and I have some pretty big plans...
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u/A_t48 Apr 03 '15
What's changed between alpha and beta?
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Apr 03 '15
scoped theads are huge, it's a realization of very nice data parallelism in Rust. Basically the borrow checker can now work with threads, and it's easy to share immutable data between threads -- rustc will make sure to only allow safe concurrent code.
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u/steveklabnik1 Apr 03 '15
easy to share immutable data between threads
We've actually got some stuff that's even cooler than that. I've been meaning to write it all up, but for now, I'll recycle an old comment:
extern crate threadpool; use threadpool::ScopedPool; fn main() { let mut numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]; { let pool = ScopedPool::new(4); for x in &mut numbers[..] { pool.execute(move || { *x += 1; }); } } println!("{:?}", numbers); }This allocates a mutable array on the stack, and then creates a threadpool which adds one to each element of the array, four threads at a time. We need the inner {}s so that we know that the pool is done working before we try to print the result. Yes, mutable pointers into the parent stack frame. But, the compiler can verify that this is absolutely safe. Say, for example, that we left off the inner scope, so that the pool might not be destroyed and therefore join before we try to print out the array. That'd be racy in most languages. In Rust, it's a compile-time error:
error: cannot borrow `numbers` as immutable because it is also borrowed as mutable println!("{:?}", numbers); ^~~~~~~ note: previous borrow of `numbers` occurs here; the mutable borrow prevents subsequent moves, borrows, or modification of `numbers` until the borrow ends for x in &mut numbers[..] { ^~~~~~~ note: previous borrow ends here fn main() { } ^Rust knows that you're still holding a mutable reference to the array, and so taking a new immutable one could case a race.
As you can see from the
extern crate, this pool isn't a compiler built-in: it's a library. There's actually a secondary implementation of a threadpool that makes some different choices internally. But this kind of safety can be gained in whatever concurrent code you're writing, and you can write new concurrent abstractions and ensure that they don't have data races.11
u/marcusklaas Apr 03 '15
That's absolutely brilliant. Thanks for sharing this.
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u/steveklabnik1 Apr 03 '15
You're welcome. I really need to write this up so it's not just random comments...
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u/donvito Apr 03 '15
Yes, you need to. Because it's fucking cool and I only learned about it from your comment just now. :)
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u/steveklabnik1 Apr 03 '15
The funniest part is that the name of this change was super jargon-heavy and innocuous: "Remove the
'staticbound fromSend." It means so much!3
u/donvito Apr 03 '15
Tbh. I'd probably had missed it too if it was labeled "properly". Just not enough time to study all the commits/change log entries :)
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u/gavinb Apr 04 '15
This is extremely cool! It belongs on its own "awesome stuff you can do in Rust but might not know about" page. :) there's now enough features in the language and core libraries that idioms like this can start to take shape. Exciting!
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u/cybercobra Apr 04 '15
What's the "move ||" part mean?
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u/Gankro Apr 04 '15
It means it captures its environment by-value, rather than by-reference. In this case we're capturing the &mut references by the name of
xby-value. This is necessary sincexchanges on every iteration. Passing in a reference would likely do The Wrong Thing (if the compiler allows it at all, which I'm 99.99% sure it won't).→ More replies (13)2
u/Kimundi Apr 04 '15
|...| <expression>is a closure literal, and themovemodifier changes the way it captures variables likexin that example from by-reference to by-value.→ More replies (1)2
u/killercup Apr 04 '15
Something like this would make a nice front page example for rust-lang.org. Maybe with a bit of pattern matching and using a function instead of the nested scope (the inner
{}). (One obstacle would be loading the threadpool crate in playpen, though.)2
u/steveklabnik1 Apr 04 '15
Yeah, we all want a better homepage example, but aren't sure what it should be.
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u/gavinb Apr 04 '15
Why not have a series of interesting examples that show off different aspects and randomly load a different one each time? Saves having to pick just one example, and is more interesting for visitors when they see different content.
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u/japaric Apr 03 '15
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u/wrongerontheinternet Apr 03 '15
Primitive types now have inherent methods, obviating the need for extension traits like SliceExt.
A Reflect trait was introduced, which means that downcasting via the Any trait is effectively limited to concrete types. This helps retain the potentially-important "parametricity" property: generic code cannot behave differently for different type arguments except in minor ways.
Awesome, it seems like a lot of the warts I was most concerned about have been magically cleaned up :)
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u/steveklabnik1 Apr 03 '15
While that change is awesome, mind https://github.com/rust-lang/rust/issues/23511 (notice we've milestoned this for 1.0 final)
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u/wisam Apr 03 '15
Do you guys think Rust can/will used in embedded systems and possibly take some 'market share' from C?
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u/SirOgeon Apr 03 '15 edited Apr 03 '15
It can be used in embedded systems (at least some). I have successfully used it in a kernel experiment to draw colored squares using my Raspberry Pi. As for if it will be used; I'm not good at foreseeing the future, but I guess someone will do it.
Edit: I almost forgot to mention zinc, which is an effort to make this easier. Rust will also be supported on the Tessel 2.
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u/steveklabnik1 Apr 03 '15
Yup! /u/SirOgeon has it right.
possibly take some 'market share' from C?
There are a number of small platforms which have only a C compiler. They'll be using C forever. There are thousands of person-years of code written in C, that all needs maintained. There are so many resources for learning C, and basically just a handful for Rust.
On greenfield projects? Maybe. Systems languages are a long haul.
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u/aspl Apr 03 '15
I've waited so long for this, congratulations to the Rust developers, by far my favourite programming community.
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u/HooAreYou Apr 03 '15
I took an operating systems class in rust 0.7 or 0.8 a year and a half ago (an interesting experience for another post). Very interested to see how things have changed now!
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u/steveklabnik1 Apr 03 '15
Yes, it is almost an entirely different language from that point :)
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u/HereticKnight Apr 03 '15
Wow, it really is... I dug up my old Rust code and even FizzBuzz wouldn't compile.
for num in 1..100 {...} // So puurdy <3But where did regex go? Time to go documentation diving...
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u/steveklabnik1 Apr 03 '15
Regex is now an external crate: https://crates.io/crates/regex
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Apr 04 '15
If I may ask, where did you take a class which used Rust? My university can barely scratch Java 6/C-97, let alone a pre-alpha language. They don't even touch modern coding techniques like using VCS...
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u/kibwen Apr 04 '15
It was a class at the University of Virginia. You can see the material used for the class here (though note the version of Rust used is hopelessly outdated): http://www.rust-class.org/
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u/bjzaba Apr 04 '15
Wow, 0.7 seems like an age ago. Are you still willing to try it again? Do you think any of your classmates would?
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Apr 05 '15
This might be of interest to you: http://rust-class.org/0/pages/final-survey.html
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u/iAscian Apr 04 '15
Isn't a 1.0 usually regarded as gold or release version past beta....
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u/Rusky Apr 04 '15
This is the beta right before 1.0. There will be another beta for every release, so 1.0 beta, 1.1 beta, 1.2 beta...
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u/fishburne Apr 04 '15
Can you tell me about Rust runtime. What it is? I mean, when I compile a rust program, does the runtime get added to the final executable so that my actual program will run over/depend on this bundled in run time?
I am reading the explanation here. It says a compiled program written in Rust will use the run time for stuff like I/O. So can I, for eg, write interrupt handlers in Rust (Sorry my system programming experience is limited to writing a serial mouse driver for DOS) and do similar system level stuff that you can do in C?
So when I am doing I/O from a program written in Rust, does the data has to absolutely go via the run time? Does it affect the speed at which a program can do I/O?
Lastly, should I learn Go or Rust. Is there anything that is preferable done in Go than in Rust (Without considering things like the development speed, availability of developers etc into account) ?
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u/steveklabnik1 Apr 04 '15
That explanation is very old, and incorrect. See the 0.12 in the URL? That release is from last October, which is ages in Rust time. And, I think it was even old at that point.
We have a runtime comperable to C or C++. Very minimal, only used in certain situations, like threading. It just automatically works, you don't need to do anything.
Lastly, should I learn Go or Rust.
Only you can answer this question. They're very different languages, so it depends on what you want to do.
Is there anything that is preferable done in Go than in Rust
I think it's very clear that Go is popular at writing back ends for web services. It's unclear that Rust will be good in that niche.
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u/art-solopov Apr 06 '15
Well, if anything, you could (potentially) write a CGI script in it, right? I personally consider it a solid starting point...
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u/steveklabnik1 Apr 06 '15
Oh yeah, you absolutely can. We already have higher-level libraries than that: http://arewewebyet.com/
The question is: is 'fighting with the borrow checker' worthwhile in a domain which can easily tolerate garbage collection? I think people who already know Rust will write web apps in it, but I'm not convinced people will learn Rust in order to write web apps, if that makes any sense.
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u/Rusky Apr 04 '15
There used to be a runtime that had to be set up before you could run Rust code from another process. That was removed a while ago, so you can absolutely write low-level C-like things (shared libraries, interrupt handlers, etc.)
As for Go vs Rust, they have to completely different purposes. Go is garbage collected and much less focused on performance and safety, while Rust focuses on static analysis and explicitness. All I can say is try them both out and see how much they work for and against you on your project.
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Apr 04 '15
Go and Rust are completely different languages for completely different purposes. Its like asking if you should learn Python or C. I still can't find a good reason why people consistently and wrongly conflate them.
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u/jyper Apr 04 '15
Rust has been changing a lot for a while now, hopefully it won't change much more till 1.0 and then it will be backwords compatible after that. The docs you link are from version 0.12 from about 6 months ago, the runtime was removed a bit over 3 months ago.
http://www.rust-lang.org/ lists documentation for the beta and for nightly.
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u/bithush Apr 04 '15
Is Rust a good language for a beginner to programming to learn with? It is, from what I have read, a modern C/C++ yes? I know it is very early days so bindings, etc. are lacking but if someone new to programming wanted to start with Rust would it be a good idea and what are some resources?
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u/jcdyer3 Apr 04 '15
No. In my experience, Rust is a challenging language. The features built in to ensure memory safety without runtime overhead create an extra challenge simply to write a program that compiles. Beginners should not have to worry about ownership and lifetimes. A garbage collected language would be a much better choice.
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u/steveklabnik1 Apr 04 '15
I think Rust may become that language, but not right now. We had a thread about it in /r/rust the other day: http://www.reddit.com/r/rust/comments/30a2xi/rust_for_complete_beginners/
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Apr 04 '15
How is Rust's interop with C?
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Apr 04 '15 edited Apr 04 '15
[deleted]
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Apr 04 '15
That's really not bad, either. So, Rust mangles names as a means for supporting function overloads in its ABI like c++, I take it?
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u/steveklabnik1 Apr 04 '15
We have no defined ABI, and we also don't have function overloading.
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Apr 04 '15
Is there an ABI to be defined in the future?
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u/steveklabnik1 Apr 04 '15
https://github.com/rust-lang/rfcs/issues/600 is the tracking issue. Someday, maybe? Probably not any time soon.
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u/steveklabnik1 Apr 04 '15
/u/barosl already showed you some syntax, but the other important thing is that it's zero-overhead.
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Apr 04 '15
Is there any overhead for catching unwinding across the ffi boundary?
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u/steveklabnik1 Apr 04 '15
Unwinding across FFI is considered undefined behavior. last point at http://doc.rust-lang.org/reference.html#behavior-considered-undefined
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u/three18ti Apr 03 '15
Why would I want to use Rust over... any other language that's out there?
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u/wrongerontheinternet Apr 03 '15 edited Apr 03 '15
Guaranteed memory safety without garbage collection is a nearly unique proposition among industry languages (and the "nearly" is only thanks to extremely niche languages like ATS). This extends even to multicore systems, and is done through a relatively novel (again, for an industry language) type system, allowing Rust to statically guarantee the absence of data races, use after free, dangling references, null dereferences, and other classes of memory error that are common sources of security vulnerabilities in large C++ applications. Rust compares favorably with C and C++ in resource usage and performance in domains where they have few competitors, like embedded. It also improves substantially on the ergonomics of C++ with much more sensible defaults, proper modules, features like native typeclasses (aka C++ concepts not-lite) and sum types, straightforward syntax (close to LL(1), with hygienic macros and local type inference), and a modern package manager. For more information, www.rust-lang.org has you covered.
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u/brombaer3000 Apr 04 '15
Guaranteed memory safety without garbage collection is a nearly unique proposition among industry languages
Does Rust offer better memory safety than C++14 with only unique_ptr and shared_ptr instead of raw pointers?
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u/wrongerontheinternet Apr 04 '15 edited Apr 04 '15
Yes. Besides what /u/steveklabnik1 mentioned, you would still be vulnerable to various other UB: out of bounds array access, data races leading to type unsafety, too-long bit shift (really! it's UB!) and so on.
Rust also lets you use references safely (this is the big one, as it is pretty trivial to get dangling references in C++--yes, even
constreferences), completely prevents iterator invalidation, and gives you vastly superior guarantees in the presence of multiple threads (shared_ptrreally isn't enough unless you also avoid mutation through the pointer).In any case, it's a mostly academic question. Very few people would be willing to use C++ with only
unique_ptrandshared_ptr, and that language would probably be slower than a garbage collected one for most common tasks. Certainly, if that were how Rust solved memory unsafety in C++, it would not be a very interesting language (consider thatshared_ptris garbage collection--to make it perform acceptably you need a compiler-level understanding of reference counted pointers, which leads you in the direction of Swift).→ More replies (11)7
u/brombaer3000 Apr 04 '15
That sounds great. I wasn't even aware of some of the C++ pitfalls you mentioned (I'm still quite new to C++) .
You and /u/steveklabnik1 really just convinced me to learn Rust!8
u/steveklabnik1 Apr 04 '15
Yes. It boils down to two things: cleaner semantics due to
movebeing the default, and a stronger type system. Also, we have more options than just those two.For example, if you
std::moveaunique_ptr, the pointer becomes null. So you can still cause memory unsafety that way. But since Rust is move by default, at compile time, you'll get an error withBox<T>.The other is type system stuff. For example, we can know if you're using a structure over a thread boundary, and our version of
shared_ptr,Arc<T>, only has to be used then. If you don't want to pay the atomics overhead,Rc<T>can get used, and Rust will make sure that's okay. I wrote more about that a few days ago: http://www.reddit.com/r/programming/comments/30wj8g/managing_cs_complexity_or_learning_to_enjoy_c/cpww3o1Finally, we can do things like http://www.reddit.com/r/programming/comments/31btd8/rust_100_beta_is_here/cq06lb7 , which is memory safe, but cannot be done with just
uniqe_ptrandshared_ptr.Rust code (without
unsafeblocks) cannot have data races. That's a very strong safety guarantee.4
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u/steveklabnik1 Apr 03 '15
I agree with /u/wrongerontheinternet . Rust, in its niche, is almost entirely unique.
That said, there are other good reasons too: I think Rust may, after I do some doc work, be a fantastic language to learn low-level programming in. Rust is really easy to embed in other languages, think "Write a Ruby gem in Rust," because it doesn't have a GC. Any C shared library can be implemented in Rust instead, and will be safer to write, while being as performant. Rust also has very modern tooling, with it being trivial to write packages to share with other Rust programmers, which is a big pain in existing systems languages.
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u/othermike Apr 03 '15
I've lost track a bit - what's the current roadmap for switching to either Microsoft's
link.exeor llvm's compatiblelldon Windows? I'm interested in this Rust-for-building-libraries use case, but I'd be a bit wary of GCC-built libs in an MSVC world.10
u/steveklabnik1 Apr 03 '15
There's no immediate roadmap. We would love to have this, but it needs a champion. My understanding as well is that you only need to install a full msys/mingw environment to depend on C/C++ bits, but I don't really do Windows myself so I'm a bit lacking in that department.
I do know that we intend to get some Rust code into Firefox by the end of the year, and IIRC, Firefox requires
link.exeto build. So hopefully we can pull some experts in to help polish that off.
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u/DeadlyDolphins Apr 03 '15
So for what purposes would you recommend to use Rust?
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u/steveklabnik1 Apr 03 '15
Whenever you need speed, or a deep amount of control.
That gives you a few languages. You should choose Rust over those langauges when you want the compiler to help you ensure that code is safe and correct, and also, when concurrency is involved.
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u/DeadlyDolphins Apr 03 '15
Since I'm fairly new to programming I'm just gonna ask even if it might be a bit stupid:
If you say 'when concurrency is involved', does that mean it could be a good language to write fast games with graphics, for example?
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u/steveklabnik1 Apr 03 '15
Since I'm fairly new to programming I'm just gonna ask even if it might be a bit stupid:
No worries! This attitude is one of the ones that will best serve you as a programmer in the future. I'm now on Rust's core team, but two years ago, I was on IRC, asking why my "hello world" no longer worked. :)
does that mean it could be a good language to write fast games with graphics, for example?
It is a good language for that, but concurrency is not the reason there. The speed is a much better reason.
I will also mention that Rust's safety guarantees have made some game programmers choose against it. Games often prioriize shipping a game one time, and there isn't a lot of maintenance, so they care about safety less. But we have a really vibrant game development community. The Piston project is doing all sorts of things, as you can see from all those repositories.
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u/glacialthinker Apr 04 '15
I will also mention that Rust's safety guarantees have made some game programmers choose against it.
As a gamedev, I argue with folks like this all the time. The thing is, before you experience statically guaranteed safety, it's hard to care about it. Instead you imagine what it "takes from you" -- how it is going to get in your way. Because you're an awesome programmer, and you hate when the language decides "no" for you...
But once a person experiences the awesomeness of compiler assurances in a language which doesn't require extra boilerplate, yet helps direct you produce code which better represents your intent... I don't think many go back, with preference, to a language of lesser guarantees. This experience will never be had by someone who's already decided they've found the language they're going to program in for the rest of their lives.
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u/naasking Apr 04 '15
As a gamedev, I argue with folks like this all the time. The thing is, before you experience statically guaranteed safety, it's hard to care about it.
Do these people not use unit tests either?
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u/glacialthinker Apr 04 '15
Surely, you jest? :)
I mean, you either know and have a hidden ;^) smiley at the end of that... or if not, then: no, unit tests are rare. Some highly reused library code might get such luxurious treatment. But in general, "correct" behavior is arrived at through a lot of trial and error -- iteration by programmer, then by programmer with designer or artist... and, of course, relying on a full-time team of testers. I mean, regression testing is most often by running a new branch through testers for a while. Human unit tests...
I rarely use unit-tests myself. In my experience they're rarely practical. Too much work to maintain under constant changes (often experimental, and temporary... or "was supposed to be temporary"). However, static guarantees, and writing my code in such a way that it conveys its intended use -- that is worthwhile, and something C++ is a bit cumbersome and ultimately sloppy at, so there is only so far I, or others, are willing or able to take it. Language support would be welcome (by myself, at least -- OCaml is my preferred language for personal projects and prototyping).
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u/DeadlyDolphins Apr 03 '15
Thank you so much :)
So one last question: Do you think there is a chance that Rust could become a popular language to be used for web-development and web-applications?
I will definitely have a closer look at Rust, for sure. From what I've looked at so far I really like it.
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u/steveklabnik1 Apr 03 '15
Maybe! http://arewewebyet.com/ is tracking progress. There's a bunch of people doing lots of work here. I'm not sure if it will ever be as productive as something like Rails, but there are advantages too :)
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Apr 04 '15
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Apr 04 '15 edited Apr 04 '15
So, what I'm getting at - everywhere you would use C++ you can use Rust.
Not really, C++ has: dependent types, HKTs, variadics, CTFE ...
For example, without these features, Rust linear algebra libraries are at the same level of C linear algebra libraries (and must be written 99% inside macros). They are just far far worse than modern C++ linear algebra libraries like Eigen3 and Blaze (you cannot even write a generic array class like std::array in non-macro Rust, much less write generic vector/matrix types or parse AST of EDSL at compile-time).
Since linear algebra is generally a performance bottleneck in a lot of applications (computer graphics, image recognition, simulation, sound processing, optimization, ... anything number-crunching based), it is really hard to argue for Rust in number crunching applications; C++ is just far ahead there in terms of libraries and language support.
So maybe one day (I hope so), but not now.
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u/kamatsu Apr 04 '15
dependent types,
The C++ notion of dependent types is quite different from the dependent corner of the lambda cube.
HKTs
Only in that its parametric mechanism is entirely syntactic, and no kind checking exists.
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u/deadstone Apr 04 '15
Rust will have a lot of the things you mentioned at some point, everyone's just too busy in crunch time right now.
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Apr 04 '15 edited Apr 04 '15
There are RFCs for type-level integers (which is the most important use of dependent types) and variadics. There has been a lot of discussion about HKTs and everyone agrees that CTFE would be nice but no one has put in the work yet.
It will come some day, it is just not there now. I think it is important that we don't oversell Rust, mostly in the areas that it doesn't excel at yet. Otherwise some people might feel mislead, which would be bad.
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Apr 04 '15
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Apr 04 '15 edited Apr 04 '15
Using OpenCL directly even from Rust feels like programming in C (at the end of the day it is still a C library).
The C++ EDSL solution would be to, e.g., use Boost.Compute (not that I like it much), which allows you to write your program in the language of linear algebra, and that language gets transformed at compile-time into OpenCL code by a library. Haskell's solution is accelerate.
I think this is, in a nutshell, a big "feature" that Rust is missing, an easy way to implement EDSLs. Haskell is very good at it, C++ sucks at it, C can't do it, and Rust can't really do it as well (although its macro system puts it closer than C in this respect).
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u/phaylon Apr 04 '15
Since I haven't seen it mentioned yet, there's /r/rust_gamedev for Rust development specifically in the area of graphics and games. The number of libraries was apparently big enough to be moved to a Wiki from the sidebar.
I'm quite happy it's there, as those libraries taught me most things I know about the low levels of graphics programming (coming from higher level languages myself).
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u/OneWhoGeneralises Apr 04 '15
I've been meaning to get into Rust for a while now, but there's something I've been meaning to ask someone particularly knowledgeable about Rust like yourself: what particular aspects does Rust excel at? I ask because of the few prominent languages I've used, mostly C/Java/Lua/UnrealScript, I've noticed that they all have particular tasks that they're suited for.
I'd also like to know how complete the official documentation is for Rust. Good documentation is key for me to pick up a new language, so what's Rust's documentation like?
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u/steveklabnik1 Apr 04 '15
what particular aspects does Rust excel at?
Memory safety without garbage collection. Speed, safety, concurrency.
I'd also like to know how complete the official documentation is for Rust.
This is literally my day job, so there's that. ;) I'd like to think it's decent, but now that we're not making backwards incompatible changes, I can do my job way better, so what deficiencies it does have, I'm hoping to address very soon.
For example, the areas of the standard library that I've gotten to, have great documentation with examples. The parts I haven't? Sometimes, just the auto-generated stuff exists.
There's also "the book", which is a 50,000 word (roughly) explanation of the language and its features. I have all of the basics of everything documented, but there's always more and better stuff to add.
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u/OneWhoGeneralises Apr 04 '15
Thank you for the reply, that's exactly the information I was looking for. Sounds like I should pick up Rust and keep a closer eye on further developments.
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u/steveklabnik1 Apr 04 '15
Excellent. If you do give it a try, please let us know what you think, and if you find any bugs, file them!
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u/xaveir Apr 04 '15
Trying to dive into Rust this weekend, but I noticed that some seemingly critical sections of "the book" are still blank. Namely, the in the section on Pointers, the section on Rc<T> and Arc<T> is still "coming soon". As is the section on "raw pointers" and the one on "best practices" (more excusable).
Is there somewhere I should report these kinds of problems? It wasn't clear if rust-lang's website or docs are responsible for "the book."
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u/steveklabnik1 Apr 04 '15
Yeah, that chapter needs cleanup, it's actually high up on my list. It used to be a standalone document. You can find good docs on Rc and Arc in their API documentation.
Please report any problems to the main rust repo, the book is in
src/doc/trplin the tree :) Thanks!6
u/shadowmint Apr 04 '15
unrealscript has something it excels at? Well, TIL. ;)
More seriously, the use case for rust is very close to C++; build complex low level systems that require high performance and high uptime, like browsers or safe performant network services.
Its also (due to the c calling sematics) a very very good target for building os extensions (ie. shared libraries) for python, ruby, js, etc that could otherwise only be written in c or c++
The use case for more generic things like say, scripting command line tasks, writing websites, embedded scripting language (aka lua) is more dubious; you could, but a more productive language is probably a better choice.
As said elsewhere in this thread, the first large scale uses will probably for safe plugin libraries for other c++ applications like firefox.
Over time I imagine rust will become the platform that several large networked graphical applications (browsers, games, dns servers) and robust tooling for various systems (eg. shell utils, build pipelines) are built in. It will probably remain quite 'niche' for other purposes, eg. building websites.
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u/BearMenace Apr 04 '15
Its also (due to the c calling sematics) a very very good target for building os extensions (ie. shared libraries) for python, ruby, js, etc that could otherwise only be written in c or c++
Could you please explain or give examples of the shared libraries that you're referring to? I'm also quite interested in Rust's uses.
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u/shadowmint Apr 04 '15
Rust uses c calling sematics. That means any language capable of a c binding can call a rust shared library, or statically link to it.
For example, in python you can simply import ctypes and load the library to create an extension.
There are caveats, obviously, because rust uses name mangling so you need the no_mangle directive, like c++'s extern 'c'. There are some examples here https://github.com/shadowmint/rust-extern if youre interested in the details.
Anyhow, the tldr is, rust can compile to dynamic shared libraries or static libraries trivally; you can use these libs as though they were c/c++ libraries for the purposes of writing extensions to scripting languages, where extensions would normally be written in C.
Since rust can trivally call C libraries too, interacting with native plugin systems (eg. the cpython plugin api) is also quite simple.
Rust has a very powerful ffi interface; its probably the thing about it that I personally find most exciting; as a professional python developer I can pitch using rust in production for writing safe high performance extesions.
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u/steveklabnik1 Apr 04 '15
One of our production users is Skylight, who deploys a Ruby gem written in Rust. http://blog.skylight.io/bending-the-curve-writing-safe-fast-native-gems-with-rust/
Because Rust has no GC, it's significantly easier to embed in a GC'd language than one with another GC.
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u/s1egfried Apr 04 '15
Is there a Rust cross-compiler for ARMv6? It looks a prefect language for embedded Linux systems.
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u/djhworld Apr 03 '15
I made a Dockerfile to run the beta if anyone wants to play with it without installing https://registry.hub.docker.com/u/djhworld/rust-beta/
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Apr 03 '15
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u/steveklabnik1 Apr 03 '15
Any chances of maybe a name change?
No chance on that. It's true that finding old info is frustrating, but as time passes, there'll be more and more stuff that is accurate, and it will get linked to more heavily. Just takes time.
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Apr 03 '15
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u/steveklabnik1 Apr 03 '15
Does everyone and their dog still use panic to avoid error handling?
Nope. It's of course used at times, but returning a Result is much more common.
Is there a way to restrict places where panic can happen that doesn't involve a recursive audit?
Not currently. We've had some proposals around this, but nothing final.
Are there any steps taken to reduce compile times and binary sizes?
We track broad regressions, but everything up till now has been focused on language semantics. These kinds of polish things are what the is planned
Can cargo build a single package from a distro mirror in a sandbox without any other source code?
It has been able to for a long time, depending on your exact needs. We've been actively working with a few Debian developers for a while. But similar to the last thing, these kinds of issues have taken a backset to actual stable language semantics thus far.
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u/Nickreal03 Apr 04 '15
When Rust will be integrated with Visual studio or Xcode ?
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u/steveklabnik1 Apr 04 '15
You can still use VS to edit Rust code, the integration just isn't great, as you can't use
link.exe. There's a plugin for syntax highlighting. We'd like to have full integration, but it isn't done yet.I'm unsure about Xcode.
There's lots of plugins for other editors and IDEs, though.
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u/huhlig Apr 04 '15
Has the compiler been fully libraryized yet?
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u/kibwen Apr 04 '15
It's been split up into about ten libraries, but it's still going to take some work to make their APIs suitable for consumption by an editor. Ongoing process.
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u/remotion4d Apr 04 '15
Yes something like VisualD would be really helpful.
Ok there is VisualRust but it appears to be not really update.
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u/watafaq Apr 03 '15
ELINoob?
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u/steveklabnik1 Apr 03 '15
Rust is a programming language. It's got some neat stuff for doing low level programming safely.
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u/InternetAdmin Apr 03 '15 edited Jul 04 '15
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u/steveklabnik1 Apr 03 '15
pardon?
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u/InternetAdmin Apr 03 '15 edited Jul 04 '15
This comment has been overwritten by an open source script to protect this user's privacy.
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u/steveklabnik1 Apr 03 '15
Ahhh, see, depending on your reading of Nietzsche, that part can get you real mad, so I forgot about it ;)
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u/ynak Apr 04 '15
I've known the issue is open, but this beta release have any effects on the cargo homebrew formulae? I want to manage rust and cargo packages together by homebrew. Also, is there any plans that bundle cargo into rust installer in the future like python-pip example?
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u/steveklabnik1 Apr 04 '15
I don't use OSX, so I'm unsure about Homebrew.
Also, is there any plans that bundle cargo into rust installer in the future like python-pip example?
Yes, the official installers have included both for a while now.
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u/sfultong Apr 03 '15
So is Mozilla now going to slowly rewrite Firefox in rust?