macOS Apps in Rust (opens in new tab)

Rust codebases extend in size and scale to larger teams fundamentally better than C++ / C. Rust offers more leverage in building ambitious system software.

Since you mention Qt, imagine writing all of Qt in x86 assembly, vs. C++. "There's not particular reason this isn't doable." C++ to Rust is a similar jump. No silver bullets; just leverage.

Cross-platform toolkits — especially those aiming to abstract over native UI/UX patterns — are an ambitious, if not Sisyphean domain. Qt was about the best we could do in the C++ era, but a new era has dawned.

> “Abstracting” away the native GUI/UX seems to be a common pitfall for junior devs

I would like to know more about what you mean here; my description of a "virtual UI" that you bind to from the native toolkit is an abstraction to the UI - but it's not an abstraction like Flutter which tries to merge all native widgets into abstracted widgets. My concept still requires you to write multiple native entry points using the UI kits of the target platforms.

` (GTK entry || Cacao entry || Win entry) => Virtual UI => application logic `

The idea is that the virtual UI would be an in-memory representation of the UI (have virtual buttons, labels, etc). It would be the job of the entry to correctly represent/bind to that virtual UI with the relevant presentation tool kit. The output binary would be specialised to the platform/UI kit used in the source entry point.

It seems sensible on the surface to decouple the UI from the native presentation as it minimizes the requirements of the native side to constructing the UI and binding to the virtual UI - but I would love to hear your thoughts.

I have not tested this architecture outside of web development but I imagine adding new UI targets (like web assembly, QT, etc) would be easier as it wouldn't require any changes to the virtual UI or application logic and would be a matter of creating a new entry point representing the UI for the new target.

> then they learn why Qt exists

Does QT feel native on MacOS, Windows and Gnome?

> Yes it is [talked about]

Could be my personal echo chambers talking here - but multithreading is almost never spoken about and/or often intentionally disregarded in modern web/electron applications.

It sucks because so many applications are written using Electron or other similar web wrappers.

> there isn’t a particular reason this hasn’t been doable in C/C++ since forever - Rust isn’t some silver bullet

Not dismissing this, I was more impressed that Rust offers a thread safety guarantee through its ownership model making it interesting from a contributor scalability standpoint.

I was thinking that it might make it easier to have more engineers working on a high performance GUI project because it would be significantly harder to break.

As an example; I could imagine if a company assigned a team of TypeScript/JavaScript developers with different experience levels onto a GUI project written in something like Go, there would be a lot of thread safety issues and seniors would spend a lot of time combing PRs for thread safety issues.

Rust, while perhaps not as simple from a syntax/types/symbols standpoint, offers an interesting development modality for these sorts of projects. I would expect that it would result in a more hands off contributor experience.

> Electron is about as far removed from the philosophy of targeting platform native toolkits as one can get.

Sorry I wasn't describing Electron as targeting platform native decorations - just that it promises an OS agnostic UI framework (write once run anywhere) at the expense of a diminished native experience and poor performance.

My point was that it might be interesting to explore the idea that a multi-entry native toolkit application fulfils the same "write once run 'anywhere'" promise but without the downsides.

And why wouldn't a hybrid approach work? I.e. the majority of the code using the cross platform toolkit, and a small amount of code per platform using the native API.

I agree with your statement about modern toolkits being no better than Java, but Java is pretty good. I’d have no problem starting a new project with it today.

All that said, I’d much rather have a well written native application than a well written cross platform application.

Instruction for building apps in AppKit has always been kind of spotty. When I first started learning it alongside Objective-C in the 2000s, the best a beginner could really do was sift through random blogposts and mimic patterns seen in FOSS Mac apps. The best resources at that point were probably the various books on the topic (such as the Big Nerd Ranch Cocoa books I'd seen recommended frequently) but at that point I was a broke teenager so buying books was off the table.

I would like to at some point build a one stop shop for learning all the most pertinent parts of building a Mac app with AppKit and Swift, but that takes a lot of time… if it happens it'd probably be when I'm inbetween jobs so I can dedicate the resources required to make such a thing good.