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Rust has editions to help with this. All code is backwards compatible (except soundness bugs) and if need be editions are added to allow adding breaking changes

Rust has editions to help with this. All code is backwards compatible (except soundness bugs) and if need be editions are added to allow adding breaking changes. The compiler still supports 2015 edition and will forever. You can even use different editions in the same project by importing crates that use a different edition, still overall creating a single binary. As an example of this one of the features they added was NLL (non-lexical lifetimes) which was designed to help iron out some of the annoying places the compiler couldn't see what you were doing was safe. One of the constraints they gave in implementing it was no changes to existing code that compiled, the way they did it as a non-breaking change was to ensure that the new system only allowed programs to compile that didn't compile before. It sounds like you aren't interested in Rust for other reasons but wanted to point out that language hears your concerns about breaking changes being the worst.

discreteevent 6y ago
That's interesting but I don't know if it helps with the parents concern. If I arrive into a project, the same reasons that made them choose rust mean that they have likely chosen the latest version of rust, with all its complexity and power. If I am inspecting code for safety that is doing low level things then I want to have a clear and simple (imperative) model in my head. I don't want to spend the review admiring how clever the author is. I want to know as directly as possible what is going on in the machine. In another domain the ability for the author to do clever things could make me very productive but it doesn't matter because the safety of low level code is not a concern.
- Guvante 6y ago
  "Newfangled features" and "don't be too smart for your own good" don't overlap as much as you imply. They aren't entirely orthogonal but very much so. C++'s `unique_ptr` is a "newfangled feature" but is not the latter (ignoring custom delete functionality). I tried to account for the discrediting of zero cost abstractions (which I buy) but I think you are adding the latter onto that which I didn't get from the person I was responding to. > I want to know as directly as possible what is going on in the machine Certainly not in multi-threaded code on an x64 machine (and IIRC ARM is trending in that way as well). There are too many abstractions to actually do that, the best you can do is understand the abstract machine of the language and the rough edges translating that into real machine code entails. > safety of low level code is not a concern I will remind you that in the case of Rust safety is where all of this comes from not productivity. Writing a mutex by hand is hard and you will make mistakes, here is a library construct to do it for you. It will be more complex than what you would write but it will be safer because others have worked with it. etc. etc. When working with minimal computation resources using "works for everyone" constructs stops being zero cost and starts being expensive both conceptually (what were the poisoning rules again?) and performance wise when the cost of providing your abstraction is hard (why can't I arena allocate an RC?) Those are the situations where Rust and even C++ have difficulty shining and C wins out. It provides so little you never have to pay for anything but what you absolutely need. But remember the things you lose out on are from every category you can think of, not just one. Performance, reliability and safety are all often sacrificed in some amount when writing custom code. When you write code instead of a random Joe in a garage you know who to blame when it blows up. When you write code instead of using the larger community code you give up the often great characteristics in every metric for your more fine tuned characteristics in some metric generally. Sorry that got wordy... TL;DR nothing about most low level languages up to things like Java and C# IMO stops you from having a simple imperative model in your head so using that to chose C over something else is missing the point.
est31 6y ago
You are still forced to upgrade your edition if you want to use certain libraries. I wanted to the newest versions of some async libraries and the update forced me to update my edition, otherwise I wouldn't have been able to use the libraries as they required me to use the async language feature. Also, editions are no response to the issue of new features being added to the language, changing what is considered idiomatic, okay, etc. If Rust turns out to evolve constantly like C++ has in the past, then it'll be hard to keep up with it, in addition to the great one time cost of learning it in the first place.
- steveklabnik 6y ago
  What specifically made you need to? Editions aren’t supposed to make you do that. I would be interested in hearing what we missed!
  - est31 6y ago
    Note that it wasn't a simple cargo update, but an update between two semver incompatible releases of the futures crate, from 0.1 which supported edition 2015 and provided combinators, to 0.3 which was built on the async/await feature, and required its use, because the combinators were removed. I guess it would have been hard to provide them compatibly to async/await but I'm not sure about it. Anyways, they weren't available, and as async/await is not available on the 2015 edition, I had to update the edition of the crate. The code got a lot simpler thanks to async/await so I'm very thankful for its existence.
    - steveklabnik 6y ago
      Ah yes, that makes perfect sense. I was thinking purely from the "you can still use the keywords because of the raw syntax" perspective, but in this case, that wouldn't quite work. Thank you.
      - est31 6y ago
        Yeah there is a raw r#ident identifier syntax, but no raw keyword k#kwd syntax.

discreteevent 6y ago

That's interesting but I don't know if it helps with the parents concern. If I arrive into a project, the same reasons that made them choose rust mean that they have likely chosen the latest version of rust, with all its complexity and power. If I am inspecting code for safety that is doing low level things then I want to have a clear and simple (imperative) model in my head. I don't want to spend the review admiring how clever the author is. I want to know as directly as possible what is going on in the machine. In another domain the ability for the author to do clever things could make me very productive but it doesn't matter because the safety of low level code is not a concern.

Guvante 6y ago
"Newfangled features" and "don't be too smart for your own good" don't overlap as much as you imply. They aren't entirely orthogonal but very much so. C++'s `unique_ptr` is a "newfangled feature" but is not the latter (ignoring custom delete functionality). I tried to account for the discrediting of zero cost abstractions (which I buy) but I think you are adding the latter onto that which I didn't get from the person I was responding to. > I want to know as directly as possible what is going on in the machine Certainly not in multi-threaded code on an x64 machine (and IIRC ARM is trending in that way as well). There are too many abstractions to actually do that, the best you can do is understand the abstract machine of the language and the rough edges translating that into real machine code entails. > safety of low level code is not a concern I will remind you that in the case of Rust safety is where all of this comes from not productivity. Writing a mutex by hand is hard and you will make mistakes, here is a library construct to do it for you. It will be more complex than what you would write but it will be safer because others have worked with it. etc. etc. When working with minimal computation resources using "works for everyone" constructs stops being zero cost and starts being expensive both conceptually (what were the poisoning rules again?) and performance wise when the cost of providing your abstraction is hard (why can't I arena allocate an RC?) Those are the situations where Rust and even C++ have difficulty shining and C wins out. It provides so little you never have to pay for anything but what you absolutely need. But remember the things you lose out on are from every category you can think of, not just one. Performance, reliability and safety are all often sacrificed in some amount when writing custom code. When you write code instead of a random Joe in a garage you know who to blame when it blows up. When you write code instead of using the larger community code you give up the often great characteristics in every metric for your more fine tuned characteristics in some metric generally. Sorry that got wordy... TL;DR nothing about most low level languages up to things like Java and C# IMO stops you from having a simple imperative model in your head so using that to chose C over something else is missing the point.

est31 6y ago

You are still forced to upgrade your edition if you want to use certain libraries. I wanted to the newest versions of some async libraries and the update forced me to update my edition, otherwise I wouldn't have been able to use the libraries as they required me to use the async language feature. Also, editions are no response to the issue of new features being added to the language, changing what is considered idiomatic, okay, etc. If Rust turns out to evolve constantly like C++ has in the past, then it'll be hard to keep up with it, in addition to the great one time cost of learning it in the first place.

steveklabnik 6y ago
What specifically made you need to? Editions aren’t supposed to make you do that. I would be interested in hearing what we missed!
- est31 6y ago
  Note that it wasn't a simple cargo update, but an update between two semver incompatible releases of the futures crate, from 0.1 which supported edition 2015 and provided combinators, to 0.3 which was built on the async/await feature, and required its use, because the combinators were removed. I guess it would have been hard to provide them compatibly to async/await but I'm not sure about it. Anyways, they weren't available, and as async/await is not available on the 2015 edition, I had to update the edition of the crate. The code got a lot simpler thanks to async/await so I'm very thankful for its existence.
  - steveklabnik 6y ago
    Ah yes, that makes perfect sense. I was thinking purely from the "you can still use the keywords because of the raw syntax" perspective, but in this case, that wouldn't quite work. Thank you.
    - est31 6y ago
      Yeah there is a raw r#ident identifier syntax, but no raw keyword k#kwd syntax.