Rust Survey 2021 Results

Post by foldr » Thu, Feb 17, 2022, 7:52 AM UTC

anyfoo wrote: post #123

foldr wrote: post #83

Earlier quoted context omitted.

Out of curiosity, why do you find ScopedTypeVariables essential? I've written a fair amount of Haskell code and never once needed it.

Here's some explanation (not by me, found through search): https://blog.ocharles.org.uk/guest-posts/2014-12-20-scoped-t... And among other things, it also enables pattern signatures. The official docs at https://ghc.gitlab.haskell.org/ghc/doc/users_guide/exts/scop... are generally worth a read, they start out with an example of what lexically scoped type variables allow, and follow with the design principles for the…

Post by ldiracdelta » Thu, Feb 17, 2022, 3:49 PM UTC

kinjba11 wrote: post #130

ldiracdelta wrote: post #102

Earlier quoted context omitted.

One of the pieces of OO _inheritance_ I deeply miss in Rust is the ability to subclass a library class, override *one* function, and retain all the other functionality. Yesterday, I needed to tweak the behavior of one function on actix-identity's cookie and my option seemed to be to wrapper the original object and write the same interface for the entire object, passing through every function except the one I wanted t…

You don't necessarily need inheritance. Kotlin for example has a feature wherein all that forwarding boilerplate you had to write is automated. https://kotlinlang.org/docs/delegation.html

Post by chrismorgan » Fri, Feb 18, 2022, 1:18 PM UTC

j-pb wrote: post #87

nindalf wrote: post #71

Earlier quoted context omitted.

Serious question about Zig’s comptime - isn’t that just like Rust’s const fn, except every function is implicitly opted in to being const? Where this could be a problem - I write a comptime function, only using other functions that I’ve verified can be executed at compile time. But now the implementation details of those functions (that they’re comptime) has leaked to their definition. Now a change to the impl of tho…

Kinda, but much more than that and the ergonomics are quite different as the entire language is basically available. For example in Zigs comptime, types are first class citizens which can be queried and operated on. This gives you generics without a lot of type system magic, and even const generics over arbitrary types. All without a macro system or Turing-Complete type checking (similar in flavour to the DeBruijn cr…

  #[cfg(target_arch = "x86_64")]
  …

  #[cfg(target_arch = "aarch64")]
  …

  #[cfg(not(any(target_arch = "x86_64", target_arch = "aarch64")))]
  compile_error!("unknown arch!");