Joda-Beans VS ponyc

That means I don't forget about fields (as can happen if you're just doing `person.setX()` all the time). It's easy to see what is what when reading it. I can delete fields I don't want to initialize at the time. Yes, maybe immutable objects are the One True Way, but C# lets me choose (I can label properties with an initializer `init` rather than a setter `set` and then they're immutable).

Kotlin offers stuff like this too because it's really useful toward creating code that's easy to create and maintain. Go also lets you initialize structs in a similar fashion.

Java has come back to us a decade or more late with records. They're not bad, but they're only offering one thing. They don't cover what C#, Kotlin, Go, and other languages have offered for so long.

The annoying thing about Java is that it doesn't feel pragmatic a lot of the time. It feels like the language hates stealing ideas from others. It's Java: people steal ideas from Java, not the other way around. People do crazy things just to get POJOs including Immutables (http://immutables.github.io), AutoValue (https://github.com/google/auto/), Lombok (https://projectlombok.org), Joda Beans (https://www.joda.org/joda-beans/), and maybe more. They generate lots of code at compile time or do funky runtime stuff.

It just feels like Java misses the pragmatic stuff and still kinda doesn't want to handle that. I feel a bit silly harping on things like POJOs and setting data on a new object, but that's a big part of day-to-day stuff and it definitely pushes users away from Java towards languages that seem "better" simply because they don't have Java's oddly strong attachment to not offering simple value objects. Yes, again, records do something - but it feels like Java ignored how people are using Kotlin, Go, C#, and more and didn't go for something that would have been as widely applicable and pragmatic as it could have been.

Java has a lot of great stuff like great GCs (yes), lots of cool research, great performance, and Project Loom is really exciting. I just wish the language would lean a little more practical.

I know I've been talking about properties a bunch, but let's look at Java. Java Beans are terrible - so terrible that the community has a number of workarounds. Immutables (https://immutables.github.io) lets you generate builders, Lombok (https://projectlombok.org) has their annotations that do runtime and IDE magic, there's Joda-Beans (https://www.joda.org/joda-beans/), there's the new Java Records if you want immutable-only and non-compatibility with lots of libraries, there are people using Kotlin for their data classes and Java for other things... Properties are this simple thing that lets C# work with the whole getter/setter pattern without being horribly annoying - there's just this weird { get; set; } thing that I can ignore because I don't care.

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/