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Four years with Rust

words.steveklabnik.com

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Re: Four years with Rust

#71

Post by [deleted] »

dbaupp wrote: post #58
Animats wrote: post #41

Rust as a language is now realizing the benefits of borrow checking. As the article points out, the syntax doesn't have to distinguish between move and assign. The borrow checker will catch a reuse of something already moved away. This turns out to be effective enough in practice that the syntax distinction isn't necessary. That wasn't obvious up front. Not having exceptions tends to generate workarounds which are ug…

> Rust as a language is now realizing the benefits of borrow checking. As the article points out, the syntax doesn't have to distinguish between move and assign. The borrow checker will catch a reuse of something already moved away. This turns out to be effective enough in practice that the syntax distinction isn't necessary. That wasn't obvious up front. Could you say a bit more about what you mean by "now"? You wri…

[deleted]

Re: Four years with Rust

#72

Post by stymaar »

steveklabnik wrote: post #42
Animats wrote: post #41

Rust as a language is now realizing the benefits of borrow checking. As the article points out, the syntax doesn't have to distinguish between move and assign. The borrow checker will catch a reuse of something already moved away. This turns out to be effective enough in practice that the syntax distinction isn't necessary. That wasn't obvious up front. Not having exceptions tends to generate workarounds which are ug…

? is already in stable Rust.

Is it ? According to [1] it should be available in 1.14, which is the current beta.

[1]: https://internals.rust-lang.org/t/all-the-rust-features/4322

Re: Four years with Rust

#73

Post by steveklabnik »

stymaar wrote: post #72
steveklabnik wrote: post #42

Earlier quoted context omitted.

? is already in stable Rust.

Is it ? According to [1] it should be available in 1.14, which is the current beta. [1]: https://internals.rust-lang.org/t/all-the-rust-features/4322

Must have been a bug, it landed in 1.13. I just tried it myself to triple check https://blog.rust-lang.org/2016/11/10/Rust-1.13.html

(1.14 is tomorrow, so even if that was true, I'm off by a day.)

Re: Four years with Rust

#74

Post by danjoc »

steveklabnik wrote: post #68
danjoc wrote: post #64

I really like the premise of Rust. Keep at it. For my purposes, it's still a bit too immature. Last time I looked at the big 7 things, most were still not done. https://mail.mozilla.org/pipermail/rust-dev/2014-June/010139... The RustDT plugin for Eclipse makes the edit/save/compile/flag errors loop a lot tighter for me as a beginner. The autocomplete seems incomplete though and there's no hover docs or ctrl-click thr…

A quick summary of where these are at: Internationalization / Localization / Unicode (ICU): yup, no real progress. Needs some domain experts to drive it. Date/Time : chrono is the most popular. HTTP: hyper has been good for a few years now, tokio will make it async soon. Crypto: there's lots of interesting work in this space, see ring and rustls. SQL: Diesel is the gold standard here. So, some progress! You're absolu…

Thanks for your reply Steve. You're a stand up guy. I'll look into some of these over the holiday. I want to give the new rustup a whirl.

Re: Four years with Rust

#75

Post by cesarb »

steveklabnik wrote: post #11
cpeterso wrote: post #6

It's interesting to see just how much the Rust language and libraries have evolved. Is there a wish list of breaking language changes waiting for a Rust 2.0 version?

We do have https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Ais... It is unclear if there ever will be a Rust 2.0. Even those that want it agree that unless it's incredibly easy to upgrade to from Rust 1.x, it's a non-starter.

Given what I've seen, I expect Rust 2.0 to be like C99, with Rust 1.0 being C89 (pre-1.0 is K&R C in this analogy). Even though there were a few non-backward compatible changes, it didn't fragment the C community.

Re: Four years with Rust

#76

Post by lacampbell »

Getting rid of the syntactic difference between moving and copying seems like a huge step backwards. Ditto with abandoning mailing lists for some wanky "already solved-as-a-service" web app.

Re: Four years with Rust

#77

Post by cyphar »

wyldfire wrote: post #27
cyphar wrote: post #13

Earlier quoted context omitted.

> Just my 2p for others learning: for me, Rc::RefCell was what I was missing, even after I thought I was up to speed. I started (and then stopped) learning Rust a few months ago (before their docs rewrite) and the borrow checker and concepts weren't explain in a way that I could understand. Programs wouldn't work at all, and when I read about Rc::RefCell I was scared because I wasn't sure how much garbage collection…

> So yeah. Rust definitely has problems for beginners. IMO Rust has the challenges that are very similar to all other languages have. But if you are trying to make the leap from a GC'd language like Java or Python to Rust without ever having written C/C++, you should expect to have to learn not only new language concepts but new programming concepts.

I'm a programmer that has been using C for at least 8 years, and I've been developing in Go for the past 4 (as well as a couple of years of Python here and there). The point is that I have experience in quite a few programming languages, and I am familiar with the programming concepts you're referring to.

I do not agree that Rust's challenges are the same challenges with other programming languages. Because Rust will not let you even play with the langauge unless you understand how to write safe programs (which is a concept that is defined in Rust). So there's a whole bootstrapping problem of "how the hell do I play with this thing to understand it if I can't play with it until I understand it fully". C, C++, Python, Go -- none of them have this issue. They will let you write bad code and won't stop you from running it (which I admit is not a good thing, I'm just saying that Rust's strengths are not without their downfalls).

Re: Four years with Rust

#78

Post by olauzon »

isuraed wrote: post #20
mr_luc wrote: post #4

For those of us who are getting to the party 3 years late, thank you. Just my 2p for others learning: for me, Rc::RefCell was what I was missing, even after I thought I was up to speed. I was fine using Channels for inter-thread communication and I never needed Arc, but use of Rc is common in the Rust ecosystem and a lot of my early fights with the borrow checker weren't fights I needed to have. In situations where i…

What kind of application s would Rust be an appropriate for? What languages is it largely meant to replace/improve on.

I've been using Rust to process fairly large amounts of streaming financial data. I am using Protocol Buffers (and evaluating Cap'n Proto) for network serialization and Kafka for buffering/queuing, and overall the library support is quite good.

Previously I was using JVM languages for this purpose, but grew weary of the resource footprint, and especially the unpredictable GC pauses. I am aware of the Azul JVM which removes GC pauses and of various Java techniques to avoid GC altogether, but switching to Rust provided a GC-less model from the ground-up, a powerful type system, and familiar functional programming facilities at no cost.

Re: Four years with Rust

#79

Post by Animats »

dbaupp wrote: post #58
Animats wrote: post #41

Rust as a language is now realizing the benefits of borrow checking. As the article points out, the syntax doesn't have to distinguish between move and assign. The borrow checker will catch a reuse of something already moved away. This turns out to be effective enough in practice that the syntax distinction isn't necessary. That wasn't obvious up front. Not having exceptions tends to generate workarounds which are ug…

> Rust as a language is now realizing the benefits of borrow checking. As the article points out, the syntax doesn't have to distinguish between move and assign. The borrow checker will catch a reuse of something already moved away. This turns out to be effective enough in practice that the syntax distinction isn't necessary. That wasn't obvious up front. Could you say a bit more about what you mean by "now"? You wri…

Never read "smallcultfollowing" before.

The "implicitly copyable" problem is amusing. That was dealt with by Wirth in Modula 1 with the rule "if the programmer can't tell, it's up to the compiler". Thus, non-writable objects could be passed either by reference or by copy, depending on object size. This was up to the compiler. The usual rule was that anything up to 2 words in size was copied. Since the called function couldn't change the value, it didn't matter.

This avoids philosophical gyrations. You want a rule that says you can copy ints and floats, for performance reasons. Trying to reach that via type theory makes it harder. It's an optimization.

Re: Four years with Rust

#80

Post by msbarnett »

isuraed wrote: post #20
mr_luc wrote: post #4

For those of us who are getting to the party 3 years late, thank you. Just my 2p for others learning: for me, Rc::RefCell was what I was missing, even after I thought I was up to speed. I was fine using Channels for inter-thread communication and I never needed Arc, but use of Rc is common in the Rust ecosystem and a lot of my early fights with the borrow checker weren't fights I needed to have. In situations where i…

What kind of application s would Rust be an appropriate for? What languages is it largely meant to replace/improve on.

> What languages is it largely meant to replace/improve on.

I think it's great for any problem area where you'd instinctively reach for C. System utilities, bare metal development, etc. Stuff where you care about the precise layout of memory but would prefer that a simple but non-obvious mistake didn't end up as a high-profile CVE.

> What languages is it largely meant to replace/improve on.

C. It has C's straightforward machine model in mind, like C its memory behaviours are entirely predictable, it's entirely explicit about error handling (no hidden paths of errors exiting functions as in C++).

It improves on C by adding strict checking to make managing memory safely and avoiding race conditions tractable problems.

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