>I like that. I'm stealing it :)

You led me to finally track down the name of this feature in Bash: "brace expansion"! I often wish my non-techie friends recognized this syntax, along with sed replacement syntax for fixing typos.

> I was very excited with it at the beginning, but the few times I dipped my toe it was frustrating and slow.

Okay, it definitely can be slow to compile, especially with large blocks of type-inferencing ResultBuilder DSLs like SwiftUI or RegexBuilder. I find this mostly occurs when there's a type error within the DSL, and it often takes forever for the compiler to stop trying to do inference and give up with "Type of expression is ambiguous without more context" or simply "The compiler is unable to type-check this expression in reasonable time". But in practice I rarely run into this issue unless I'm creating a massive hierarchy that should be split into smaller components anyway. And I haven't really run into issues with runtime performance yet, though I haven't made anything too performance-critical with it. In any case, Swift makes it decently easy to call out to C/C++/Objective-C if you had a performance-critical routine.

What I like about the language:

It gives me the satisfaction of languages like Rust that let me express types and logic in a way that feels "correct". I rarely feel like I'm hacking stuff in due to deficiencies in the language. Swift encourages a standard approach of record types with polymorphism but still supports legacy NSObject-based stuff in a logical way, so I never feel like I have to jump through too many hoops if I need to touch dusty old frameworks.

I like the type inference, even if it's not perfect category-theoretic Hindley-Milner magic and gets stuck sometimes as mentioned previously.

I like the `guard` statement as someone who's done a lot of Go programming and always instinctively used early returns even when my CS professors told me it was a bad practice ;)

SwiftUI is really nice to use and is the only UI framework that I've ever enjoyed using (and am hoping to write it for my job soon)--it sometimes feels more like a UI prototyping tool to me because it's so straightforward, except that at some point while prototyping, you realize you've already made the finished UI without writing a dreadful mountain of glue code and interface files!

I really like the syntax in general, though I also appreciate Rust's terse symbol-based approach, I think the English-like labels actually work really well despite being a bit verbose. It definitely benefits from an editor with autocompletion, but I wouldn't say it's strictly necessary.

I appreciate the strict Unicode-correctness of the language that makes it harder to do bad stuff with strings.

I think the ARC-based approach to memory management is a good balance between Go's GC and Rust's borrow checker that makes Swift feel like a very pragmatic choice for lots of different problems (though UI was obviously first in mind).

I really like the ArgumentParser and RegexBuilder frameworks, and I think they're the best implementations of each in any language I've used.

In general, Swift just feels good to write and easy to read while being extremely powerful in what you can create with it, and coupled with the ease of use and fast feedback of SwiftUI, feels like a very complete approach to creating many different sorts of software, for my own use or to sell.