ponyc VS mrustc

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/

No, you don't. Existential proof: mrustc ignores lifetimes. Just flat out simply ignores. It changes some corner-cases related to HRBT, yet rustc compiled by mrustc works (that's BTW mrustc exist: to bootsrap the rustc compiler).

Incidentally C++ is the only way to bootstrap rust without rust today.

https://github.com/thepowersgang/mrustc

Well, there is mrustc[0], a Rust compiler that doesn't include a borrow-checker, so it's possible to compile (at least some versions of) Rust without a borrow checker, though it might not result in the most optimized code.

AFAIK there are some optimization like the infamous `noalias` optimization (which took several tries to get turned on[1]) that uses information established during borrow checking.

I'm also not sure what the relation with NLL (non-lexical lifetimes) is, where I would assume you would need at least a primitive borrow-checker to establish some information that the backend might be interested in. Then again, mrustc compiles Rust versions that have NLL features without a borrow-checker, so it's again probably more on the optimization side than being essential.

[0]: https://github.com/thepowersgang/mrustc

[1]: https://stackoverflow.com/a/57259339

> Maybe another memory safe language, but Rust has severe bootstrapping issues which is a hard sell for distros that care about source to binary transparency.

It is possible to bootstrap rustc from just GCC relatively easily, although it's a little bit time consuming.

You can use mrustc to bootstrap Rust 1.54: https://github.com/thepowersgang/mrustc

And from then you can go through each version all the way to the current 1.72. (Each new Rust version officially needs the previous one to compile.)

Have you tried this route : https://github.com/thepowersgang/mrustc ?

Mrustc supports Rust 1.54.0 today

There are three. The official one, mrustc (no borrow checker, but can essentially compile the official rustc) and GCC (can't really compile anything substantial yet). Only rustc is production-ready though.

That probably depends on what you mean by problematic. Having an ever increasing chain of dependencies isn’t the most desirable situation so there has been some work to trim the bootstrap chain. In 2018, when the blogpost I linked above was written, mrustc was used to bootstrap rust 1.19.0; now mrustc can bootstrap rust 1.54.0 so the chain to recent versions is much shorter than if all those intervening versions back through 1.19.0 needed to be built. https://github.com/thepowersgang/mrustc