A guide to closures in Rust
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A guide to closures in Rust
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Re: A guide to closures in Rust
#2> I'll explain what the move keyword does later in the article. For now just trust me that it is needed for the code to compile.
That does not take a lot of trust, after a few rounds with that compiler. At least error messages are good with the Rust compiler. I've got very limited experience with Rust, but it does seem like a language with a massive threshold for beginners.
Re: A guide to closures in Rust
#3> I'll explain what the move keyword does later in the article. For now just trust me that it is needed for the code to compile. That does not take a lot of trust, after a few rounds with that compiler. At least error messages are good with the Rust compiler. I've got very limited experience with Rust, but it does seem like a language with a massive threshold for beginners.
It has a massive threshold for beginners for sure.
Personally I have a background in C/C++ and moved towards C#, Go, JS etc. With an interest in many more, but the above were my main languages for a decennia.
9 years ago I picked up Go, and have used it the most as my main language since then. 7 Years ago I picked up Rust, but only since 6 months ago really intensive (including publishing the guide that came out of my experience at https://rust-lang.guide/).
Over those 7 years I've only done a production project around the start of that journey and now since 6 months ago I'm writing production code in it again and haven't stopped since. But I've learned the language like 3 different times in that journey.
It's not an easy one to get into. A lot of things to wrap your head around, especially if your goal is to really master it, rather then just "woohoo I can compile my program". I still not master it, but I do feel now fluent in it and can express my ideas well. There are also no more fights with the language or its tooling.
Compared to that, Go(lang) is super easy to get into. Ridiculously easy. Perhaps too easy. You can give it to a programmer of any level, and they probably can ship their first feature that same day. The difference is however, that. First of all with Golang it's super easy to ship code with nil pointer exceptions in it or data races. I've seen it in the best code bases. And sure, plenty of people will tell if you do it "right" you'll have no issues. I've hear similar comments from ex-colleagues still in the C++ world as well. Secondly, Golang is very opinionated and if you derive in ideas or needs a bit from what they want you to do, you are in a bit of a problem. This has been slightly improved, but it's still very limited and still a lot of magic that only built-in features can perform. And thirdly, the language is very minmal (Golang). So codebases look very verbose very quickly. Also harder to express ideas (as error support is limited, and sum types are not a thing, neither are other things like pattern matchings). It's also a lot less "functional".
This is not to compare Golang vs Rust too much, even though I did. My point was more, and I probably butcher my own comment not making that point well, is that I think it's fair to have a massive threshold for beginners to get into a programming language. As long as in return it means you get a very powerful tool in rerturn to do some of your work. And Rust is def. such a tool. Many people boast about how peformant it is. And while that is true, it is for me for most projects more of an extra benefit rather than the things I really like it for. What I like with Rust is that it gives me really high confidence in my code (comparable to projects I've written in Elm and Haskell in the past). When my project compiles I really am pretty confident it will not give me runtime surprises beyond mistakes elsewhere (e.g. infrastructure choices). It's a very expressive language and pleasant to use in that way.
And then there is of course the fact that it is truly FOSS, has a very nice community, great documentation and a lot of excellent learning resources.
I am not a fanboy of much, neither of Rust, but I do really appreciate its existence and I am happy to use it where it suits. Yes it is a massive threshold, but one worth to pay.
Re: A guide to closures in Rust
#4I had a hard time with closures when doing async programming. Is that something one should avoid?
Re: A guide to closures in Rust
#5I had a hard time with closures when doing async programming. Is that something one should avoid?
I'd love to see a side by side comparison on how someone would use goroutines in Go vs tokio in Rust. Including with closures
Re: A guide to closures in Rust
#6I had a hard time with closures when doing async programming. Is that something one should avoid?
Async programming in Rust can still be a bit awkward.
They're working hard on it though. https://blog.rust-lang.org/inside-rust/2023/05/03/stabilizin...
We'll have Async traits in stable Rust after the summer (normally) and in 2024 they'll start working on supporting async closures :)
So if all is well, you're experience should start to become more pleasant next year. For now your closures will either have to return a future (without use of `async` keyword) or you better avoid it for now. Then again, hadn't really had the need for async closures, but I did had a big need for Async traits, as implementing Traits with manual futures was so far a big pain in the ass, and sometimes still not optimal. So I for one, welcome async traits with open arms.
Re: A guide to closures in Rust
#7The content is interesting but the use of ligature really put me off guard at first, and I am very familiar with Rust. I cannot imagine it being good for beginners to grok its syntax.
This has reminded me of https://news.ycombinator.com/item?id=35925821 recently reposted, which boils down to:
> if you’re preparing your code for others to read—whether on screen or on paper—skip the ligatures.
Re: A guide to closures in Rust
#8> I'll explain what the move keyword does later in the article. For now just trust me that it is needed for the code to compile. That does not take a lot of trust, after a few rounds with that compiler. At least error messages are good with the Rust compiler. I've got very limited experience with Rust, but it does seem like a language with a massive threshold for beginners.
It has a massive threshold for beginners for sure. Personally I have a background in C/C++ and moved towards C#, Go, JS etc. With an interest in many more, but the above were my main languages for a decennia. 9 years ago I picked up Go, and have used it the most as my main language since then. 7 Years ago I picked up Rust, but only since 6 months ago really intensive (including publishing the guide that came out of m…
> And sure, plenty of people will tell if you do it "right" you'll have no issues.
Go is inspired a lot by CSP, and allows you to apply CSP calculus when using goroutines and channels.
It doesn't make it impossible to make mistakes, but it does give you tools needed to reason about your concurrent program, which is more than can be said of most other languages' concurrency support.
Re: A guide to closures in Rust
#9I had a hard time with closures when doing async programming. Is that something one should avoid?
The lack of asynchronous closures does make it awkward, as you often need to put an `async move` block inside the closure for things to work correctly, which means the closure becomes an FnOnce and you have to work around that using clones.
It’s one of the worst corners of the ecosystem currently, and I’d very much recommend avoiding it.
Re: A guide to closures in Rust
#10> I'll explain what the move keyword does later in the article. For now just trust me that it is needed for the code to compile. That does not take a lot of trust, after a few rounds with that compiler. At least error messages are good with the Rust compiler. I've got very limited experience with Rust, but it does seem like a language with a massive threshold for beginners.
It has a massive threshold for beginners for sure. Personally I have a background in C/C++ and moved towards C#, Go, JS etc. With an interest in many more, but the above were my main languages for a decennia. 9 years ago I picked up Go, and have used it the most as my main language since then. 7 Years ago I picked up Rust, but only since 6 months ago really intensive (including publishing the guide that came out of m…
"And sure, plenty of people will tell if you do it "right" you'll have no issues."
My answer to that is always that if you are able to do it right in C or C++ (and maybe golang) you should not run into any issues with Rust. Especially you should not ever have to fight to borrow checker because it does the job you should be doing as a C/C++ programmer in your head anyway.