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Comment by Wowfunhappy | Hacker News Reader

For everything. Swift is—at least in theory—a general purpose language, it's not exclusively for Apple technologies.

> First off, Swift has both memory & data race safety (as of v6). It's also a modern language with solid ergonomics.

> Something that matters to us a lot is OO. Web specs & browser internals tend to be highly object-oriented, and life is easier when you can model specs closely in your code. Swift has first-class OO support, in many ways even nicer than C++.

> The Swift team is also investing heavily in C++ interop, which means there's a real path to incremental adoption, not just gigantic rewrites.

https://x.com/awesomekling/status/1822236888188498031

https://news.ycombinator.com/item?id=41208836

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> First off, Swift has both memory & data race safety (as of v6)

But v6 is not released yet, right?

next month

> > First off, Swift has both memory & data race safety (as of v6) > But v6 is not released yet, right

As of Swift 5 there is zero data race protection and the process model (DispatchQueues if memory serves) is woefully. No advantage over fork and much more convoluted

I am well clear of the Apple development world now (thank goodness) but the tools were of very poor quality, albeit very nice looking, as of this time last year

For the sake of my friends still in the world I hope Swift 6 is better, but I fear the dumpster fire that is Xcode is too far gone to rescue.

The comparison with Rust demonstrates the utility of "design by committee ". Rust is far from perfect, but feels like the future where Swift feels like warmed up Objective C

> As of Swift 5 there is zero data race protection and the process model (DispatchQueues if memory serves) is woefully. No advantage over fork and much more convoluted

Swift Concurrency is the replacement for Dispatch and has been around since Swift 5.5 in (IIRC) 2021. It’s a completely different system, uses lightweight tasks (a la tokio in rust, or goroutines in go, etc), has a concept of “Sendable” for thread-safety a la rust’s Send, async/await, and a native `actor` type, among other things.

Swift 5.5 didn’t get all the way towards rust-style data race safety due to a few things they had to make warnings instead of errors (to avoid breaking existing code), and introducing keywords like `@preconcurrency` when importing frameworks that predate Swift Concurrency, to facilitate incremental adoption. They’ve also been adding more checks in each minor release to tighten things up.

IIUC Swift 6 is mainly going to turn all the warnings into proper errors and tweak some defaults so that you get proper data race protection on a default compile.

Point is, it’s totally inaccurate to say that Dispatch Queues is all that exists in Swift 5. You’ve had much better stuff for a while now (although SC still has a ton of issues worth discussing.)

> Swift 5.5 didn’t get all the way towards rust-style data race

When I experimented with it it was trivial for one thread to interfere with another. So Swift got nowhere towards data race safety. Still stuck in the 1990s

I know not what you mean "Swift Concurrency". When I was doing it all we had was DispatchQueue which was an obfuscation of `fork`. Quite shameful really.

I think the main point is that Swift is a failure.

"although SC still has a ton of issues worth discussing" once I would have cared, but this year (decade, century) I am just very glad putting meat in my fridge no longer depends on those rouges from Apple who treated me so badly when I was sweating so hard making software for their platforms (not to mention paying them so much money). In 2024, for a company like Apple, for their flagship developer offering, why would anyone still have "a ton of issues" with it?

Apple is now an example of why popularity is a terrible metric to estimate quality of technical offerings. What a shame. How far the mighty have fallen

Okay, so you're saying you don't know what Swift Concurrency is and they say Swift is a failure.

Swift has async/await built into the language with many compile time guarantees of thread safety.

> Okay, so you're saying you don't know what Swift Concurrency

I just looked it up. It is Swift's version of async/await. That is a different thing from threads. I know what that is, used it a lot, because using threads was such a nightmare in Swift.

> language with many compile time guarantees of thread safety

From two separate threads you can access the same memory. No trouble (apart from crashes memory corruption....) at all.

Async/await is always a bad idea, and without a garbage collector it is a nightmare (look at the mess Rust has gotten into). Whatever, async/await is no replacement for parallel programming with threads. It is a different beast.

> Whatever, async/await is no replacement for parallel programming with threads.

Is it not for the vast majority of use-cases?

Sure, you can use async/await without parallelism, via a single-threaded runtime to just get single-threaded concurrency, but with a multi-threaded worker-pool async/await-like tasks or fibers I think mostly cover the use-cases you'd have for parallelism?

You have to make sure that you e.g. don't starve other tasks via having no yield points in a task that does a lot of computation (if you're doing cooperative tasks which Swift is doing iirc), but that's not a big one, and can mostly be solved by the runtime too (e.g. Go had cooperative fibers for a long time, until they chose to introduce preemption).

> I just looked it up. It is Swift's version of async/await.

Since you “just looked it up”, maybe don’t make blind assertions about something you clearly don’t know very much about?

It’s a lot more than async/await. It is a way to offer compile time guarantees about thread safety (through Sendable, which is part of SC), it’s an actor model (allowing shared mutable state to be isolated, leveraging async/await for coordination so that callers can pause if the actor is currently servicing another message) and a bunch more stuff.

I explained all this in my post you replied to, maybe read the whole thing before making wrong claims about stuff you spent 1 minute looking up?

> Whatever, async/await is no replacement for parallel programming with threads. It is a different beast.

Have you missed Tasks and Task Groups as well? And Actors? For now, they are an abstraction over threads, and IMO a good one. It’s actors + structured concurrency, borrowing from Kotlin‘s Coroutines and sprinkling some Erlang on top. Additionally, in Swift there is AsyncSequence + AsyncStream, a (woefully incomplete) Kotlin Flow alternative.

Async/await may or may not be a replacement for highly concurrent and parallel programming, depending on what is the execution model of the async runtime.

If Swift's model is anything like .NET's lightweight Tasks + async/await or Rust's async/await Futures and Tasks as implemented by Tokio or async-std, then it is such replacement.

Xcode 16 rewrote much of the autocomplete behaviors and the new engine is blazing fast in terms of UI blockage compared with 15, and stable. Everything to do with tagging etc not just completion itself.

Can you get the profiler to do anything useful? Even comprehensible?

We tried and tried but there was nothing we could use amongst the blinking lights and wonderful graphics.

Yes

I don't know if this is irony or you've been in Apple ecosystem way too long.

I had to do a very simple macOS app for my personal consumption recently and XCode dx is nothing to write home about. The only reason I finished the project there was that I couldn't set up vs code quickly for Swift/Cocoa project. I had to endure the slow compilation time, slow reaction time of the IDE UI. You make a change you keep seeing squiggly lines for a while, it's as though the UI is booting up each time. It was a horrible experience coming from IntelliJ and VS Code daily experience.

Computer is 32Gb Apple M1 Pro. Imagine what will happen on some 8Gb i5 macbook.

Xcode 16?

Swift is useless outside of macOS/iOS dev… the thing doesn’t even have namespacing. I don’t know for what reason someone would use it outside for Apple environment.

You can disambiguate two types with the same name from different libraries, e.g. `Factotvm.URL` and `Foundation.URL`. Do you mean something more full-featured? You are not prefixing types with three letters, if that's what you think has to be done.

I don't know if it's still the case, but there was an annoyance where you couldn't have a type with the same name as the package. But that is hardly a lack of namespaces.

You're right but this touches the hot stove.

HN majority doesn't like hearing that ladybird et al might just be wandering around, even if the goal is catnip for the bleachers, and we should be skeptical this is the year of multiplatform Swift, because it wasn't last year if you actually tried it. Or the year before last. Or the year before that. Or the year before that year. Or the year before that one.

I’m slightly more ambivalent than you about it. Swift is a nice language and has better ergonomics than C++ and I imagine a Swift codebase might find more contributors than a C++ one (maybe I’m wrong about that!)

I also think it’s separate from the dream of “multiplatform Swift”. For that you need a healthy package ecosystem that all works cross platform, Swift doesn’t have that. But a lot of Ladybird is written at a low enough level that it won’t matter so much.

Problem is Swift engineer supply is low, there's not a viable business case to learn Swift because it's not actually viable cross-platform for development unless you have $X00 million to throw at your macOS/iOS team to build it from scratch, platform by platform (to wit, sibling comment re: Arc Browser)

So best case we're looking at: Swift isn't ready yet, the next major version will be, and we can't build UI with it, so we'll put in the effort in to bootstrap a cross-platform ecosystem and UI frameworks. Or maybe we'll just do our business logic in it? It's a confusing mess that is irrational. Even with great blessings of resources. ex. $X00M that Arc has obtained one incremental platform after a year. And "all" they had to do was Swift bindings for WinRT and connect it to the existing C++ engine.

All of this is easy to justify if we treat it as an opportunity to shoot for how we wish software could work in theory, instead of practice. I hope I'm wrong but after being right the last few years, I'm willing to say it's naive wishcasting out loud, even though its boorish. I see it as unfortunately necessary, a younger me would be greatly misled by the conversations about it on HN. "We've decided to write the browser in Swift!" approaches parody levels of irresponsible resource management and is a case study in several solo engineer delusions that I also fall victim to.

It's genuinely impossible for me to imagine anyone in my social circle of Apple devs, going back to 2007, who would think writing a browser engine in Swift is a good idea. I love Swift, used it since pre-1.0, immediately started shipping it after release, and that was the right decision. However, even given infinite resources and time, it is a poor fit for a browser engine, and an odd masochistic choice for cross-platform UI.

> Problem is Swift engineer supply is low, there's not a viable business case to learn Swift because it's not actually viable cross-platform for development

The Swift business case is that in many situations native is strongly preferable than cross-platform. Excluding some startups that wants to go to market super fast and consulting companies that have to sell the cheapest software possible, usually the benefits of native outweighs the ones of cross platform.

For this reason now there are plenty of companies of all sizes (faangs included) that build and maintain native apps with separate iOS/Android teams. There are very good business reasons to learn Swift or Kotlin in my opinion.

Right -- no one read my comment and thought I meant Swift was unnecessary or businesses don't use it. Contextually, we're discussing Swift for cross-platform dev.

I'm glad you know what everyone thinks while reading your comments.

Well I was trying to be kinder than just leaving you downvoted and confused why. I guess I shouldn't have bothered, my apologies. Hope your week gets better!

I wonder what convinced Andreas Kling to abandon his own language Jakt [1] in favour of Swift.

In the long run, it would be good to have high-level languages other than Java that have garbage collection (at least optionally) and classes, and that are still capable of doing cross-platform system development. I don't know if Swift fits that bill, besides cross-platform ecosystem (a la Java), submitting the language for ISO standardization (not just open sourcing one implementation) would be a good indication of being serious about language support.

[1] https://github.com/SerenityOS/jakt

You might be powerfully dry here, imparting a Zen lesson. If not, or if you, dear reader, doesn't see it: it is worth meditating on that there was a language, an OS, and a web browser. Then, on common characteristics in decision-making that would lead to that. Then, consider the yaks that have to be shaved, the ISO standardization / more than one implementation hints at this.

One of the major differences between ladybird as part of serenity and ladybird the separate project is using 3rd party libraries. When what you are building are is for fun and you build everything yourself it makes sense to also build a language.

Ladybird as a separate project has the goal though of something usable in the shorter term. So similarly with switching to 3rd libraries for things I don't think it makes sense to spend potentially years first building the language before building the browser.

> In the long run, it would be good to have high-level languages other than Java that have garbage collection (at least optionally) and classes, and that are still capable of doing cross-platform system development.

> and has better ergonomics than C++

It is unfair to compare a twenty first century language with one from the 1980s

Rust is the proper comparison

The only advantage Swift has is an easier learning curve , but the ergonomics of Rust are far superior than Sift's

It’s not really a question of fairness. The existing codebase is C++, the new stuff is Swift. Hence the comparison.

I’ve written both Rust and Swift while being an expert in neither. I wouldn’t say Swift has no pluses in comparison, reference counting is often a lot easier to reckon with than lifetimes, for one. I’m actually curious what a large multithreaded Swift codebase looks like with recent concurrency improvements. Rust’s async story isn’t actually that great.

> Rust’s async story isn’t actually that great

I agree. People's perspectives differ. It abhor `async/await` in Rust. It has poisoned the well IMO for asynchronous Rust programming. (I adore asynchronous programming - I do not need to pretend my code is synchronous)

But that is taste, not a comment on poor engineering!

The lack of the borrow checker in Swift is what makes it approachable for newcomers, as opposed to Rust which is a harsh mistress.

But reference counting is such a silly idea. Swift really should have a garbage collector with a mechanism or subset to do that very small part of programming that cannot be done with a garbage collector. That would have been design!

I fear that Swift is going to get a borrow checker bolted on - and have the worst of both worlds....

I don’t think Apple would want to sacrifice the determinism that refcounting provides for garbage collection. iOS apps are still more buttery smooth than Android in many cases.

Reference counted objects have deterministic lifetimes, like Rust or C++. Garbage collected languages don't have that. Essentially a reference counter automates some* of the ideas of the borrow checker, with a runtime cost as opposed to a compile time one.

The great thing about automatic reference counting is you can elide the incrementing and decrementing a lot of the time. Stronger guarantees, such as saying "this object is single-threaded" lead to even more optimizations.

I mean this year we did have the porting of Arc browser to windows. I use it my gaming PC and it is starting to feel like it has a similar level of polish to the MacOS version.

https://speakinginswift.substack.com/p/swift-meet-winrt

https://speakinginswift.substack.com/p/swift-tooling-windows...

Now that’s not an engine but the UI.

Objective-C had some minimal adoption outside of Apple (probably due to NextStep nostalgia), so if Objective-C managed to get some traction, Swift will do it to, probably.

However, Apple's history is very much stacked against Swift becoming a mainstream language outside of Apple's platform.

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