proposal VS ponyc

The conclusion is pretty weird to me.

Go does rely on monomorphization for generics, just like C++ and Rust. The only difference is that this is an implementation detail, so Go can group multiple monomorphizations without worrying about anything else [1]. This form of hybrid monomorphization is being increasingly common, GHC does that and Rust is also trying to do so [2], so nothing special for Go here.

On the other hand, explaining variance as a lifted polymorphism is---while not incorrect per se---also weird in part because a lack of variance is at worst just an annoyance. You can always make an adopter to unify heterogeneous types. Rust calls it `Box`, Go happens to call it an interface type instead. Both languages even do not allow heterogeneous concrete (or runtime) types in a single slice! So variance has no use in both languages because no concrete types are eligible for variance anyway.

I think the conclusion got weird because the term "subtyping" is being misused. Subtyping, in the broadest sense, is just a non-trivial type relation. Many languages thus have a multiple notion of subtyping, often (almost) identical to each other but sometimes not. Go in particular has a lot of them, and even some relation like "T implements U" is a straightforward record subtyping. It is no surprise that the non-uniform value representation has the largest influence, and only monomorphization schemes and hetero-to-homogeneous adapters vary in this particular group.

[1] https://github.com/golang/proposal/blob/master/design/generi...

[2] https://rust-lang.github.io/compiler-team/working-groups/pol...

https://github.com/golang/proposal/blob/master/design/generi...

Go Team wanted generics since the start. It was always a problem implementing them without severely hurting compile time and creating compilation bloat. Rust chose to ignore this problem, by relying on LLVM backend for optimizations and dead code elimination.

Hold up, did the members actually push this forward or was support just often memed about and suddenly this proposal was made: https://github.com/golang/proposal/blob/master/design/43651-type-parameters.md

As far as I can tell, the consensus for generics was "it will happen, but we really want to get this right, and it's taking time."

I know some people did the knee-jerk attacks like "Go sucks, it should have had generics long ago" or "Go is fine, it doesn't need generics". I don't think we ever needed to take those attitudes seriously.

> Will error handling be overhauled or not?

Error handling is a thorny issue. It's the biggest complaint people have about Go, but I don't think that exceptions are obviously better, and the discriminated unions that power errors in Rust and some other languages are conspicuously absent from Go. So you end up with a bunch of different proposals for Go error handling that are either too radical or little more than syntactic sugar. The syntactic sugar proposals leave much to be desired. It looks like people are slowly grinding through these proposals until one is found with the right balance to it.

I honestly don't know what kind of changes to error handling would appear in Go 2 if/when it lands, and I think the only reasonable answer right now is "wait and find out". You can see a more reasonable proposal here:

https://github.com/golang/proposal/blob/master/design/go2dra...

Characterizing it as a "lack of vision" does not seem fair here--I started using Rust back in the days when boxed pointers had ~ on them, and it seemed like it took Rust a lot of iterations to get to the current design. Which is fine. I am also never quite sure what is going to get added to future versions of C#.

I am also not quite sure why Go gets so much hate on Hacker News--as far as I can tell, people have more or less given up on criticizing Java and C# (it's not like they've ossified), and C++ is enough of a dumpster fire that it seems gauche to point it out.

There will almost certainly not be a Go 2 in that sense. There is a Go 2 transition doc which extensively discusses what "Go 2" means. The conclusion is

As it says on that page - those were not proposals. They were draft ideas to get feedback on. You can see the list of proposals in this repository: https://github.com/golang/proposal

Approximately a year ago we faced with a necessity of limiting Go runtime memory consumption and started work on our own memory limiter. At the same time, Michael Knyszek published his well-known proposal. Now we have our own implementation quite similar to what has been released in 1.18, but there are two key differences:

For example, the actor's model is not used by a lot of languages, Pony (https://www.ponylang.io/) and Elixir are the only ones that I know, but they address the concurrency problem quite well, while it's a pain to deal with in other languages at large scale.

And that last point is critical. If the language flatly can't represent some concepts it uses, they have to be implemented somewhere else. I had a similar discussion with a proponent for Pony once- the language itself is 100% safe, and fully dependent on C for its runtime and data structures. One of Rust's core strengths is being able to express unsafe concepts, meaning the unsafe code can expose a safe interface that accurately describes its requirements rather than an opaque C ABI. Vale doesn't seem to do that.

"Exterior iteration. Iteration used to be by stack / non-escaping coroutines, which we also called "interior" iteration, as opposed to "exterior" iteration by pointer-like things that live in variables you advance. Such coroutines are now finally supported by LLVM (they weren't at the time) and are actually a fairly old and reliable mechanism for a linking-friendly, not-having-to-inline-tons-of-library-code abstraction for iteration. They're in, like, BLISS and Modula-2 and such. Really normal thing to have, early Rust had them, and they got ripped out for a bunch of reasons that, again, mostly just form "an argument I lost" rather than anything I disagree with today. I wish Rust still had them. Maybe someday it will!"

I remember that one. The change was shortly after I started fooling with Rust and was major. Major as in it broke all the code that I'd written to that point.

"Async/await. I wanted a standard green-thread runtime with growable stacks -- essentially just "coroutines that escape, when you need them too"."

I remember that one, too; it was one of the things that drew me to the language---I was imagining something more like Pony (https://www.ponylang.io/).

"The Rust I Wanted probably had no future, or at least not one anywhere near as good as The Rust We Got."

Almost certainly true. But The Rust We Got is A Better C++, which was never appealing to me because I never liked C++ anyway.

Pony or bust.

If you have a value in mutable storage, and want to treat it as an immutable parameter without copying it first, you will need to provide some way to guarantee that it won't be mutated while being treated as immutable! There doesn't seem to be a definitive best way to do that (although the likes of Pony make a try at it).

The love child of Erlang and Rust exists already: Pony.

https://www.ponylang.io

It really is the best of both languages... unfortunately, the main supporter of Pony seems to have stopped using it in favour of Rust though :D.

But if that's really what you want, Pony is your language. It definitely deserves more love.

You can actually try to have a magic language which "does not ignore decades of PL research" but you are likely to get either something broken or a project that is likely not going to release in our lifetime.

Never a bad time to plug Pony lang[1] - a safety-oriented actor-model language. In addition to the numerous safety guarantees, you also get a beautiful syntax and automatic memory management. Really a great language that often gets overshadowed by Rust's hype-turfing.

[1]: https://www.ponylang.io/