IMHO it's the best language I've used a significant amount, without a close second (where my sample size of extant languages is Swift, ObjC, Python, JS, TS, PHP, Java, Kotlin, C#, Haskell).

It's the only language I've used where I have never asked "but why?". Every language feature and stdlib API just does what it says and acts in the way that makes the most sense. You're basically forced to handle every case (null, any type of error, switch cases, etc). It's highly dynamic, yet code tends to stay understandable. Apple is thoughtful about naming things and designing APIs. It's the only language I almost never need to write utility functions for - generally the type you're operating on has a method to do what you want, which you can easily discover with auto completion. Strings are sequences of graphemes, not code units or code points, and their API reflects this.

It's not perfect, but nothing else comes as close. One of the most prominent complaints - compile time explosion - really only happens in contrived examples where you're using a bunch of literals in one expression, which isn't realistic.

However, it's stuck in a single ecosystem. And let's not talk about some of the newer frameworks. Oh, and Xcode is a joke.

And the typesystem is built in a way that it does not really help you due to typechecking being so slow. Make an error/begin refactoring in ocaml: just follow the typechecker until you’re done. Make an error/begin refactoring in swift: you plan ahead because the typechecker will crash with a timeout or give you non-root-cause errors.

Yesterday I changed the signature of a method, and instead of complaining at the callsites I got a ”ambiguous method” error for a built in SwiftUI view modifier. Kinda hard to track down if you’re not completely aware of the changes you’ve made

XCode (and other tooling) being a joke and compile issues make it tough for me to think of it as my favorite, but the language itself is definitely nice to work with.

The compile time issues I have mainly come from TCA, but I still see them from time to time in normal code.

I have a few other syntax gripes, but largely see it as competitive with Typescript and Rust in terms of how nice it is to use. TS and Rust blow it out of the water with tooling, though.

> It's the only language I've used where I have never asked "but why?"

* But why I cannot use @Published and other decorators in protocol declarations?

* But why must generics always be a pain in the ass, compared to .net, even in the most recent versions? 5 ways to do things, never the one you need

* But why is the person that designed the if case let value = .variable syntax not flagellated in a public square?

* But why is modern concurrency and SPM so undocumented?

My two mains "why tf is this not built-in" are:

"Why are tuple not Hashable ?!"

Which means that you cannot have a tuple of Int `(1, 1)` as a key in a dict, and you have to make a struct that implement Hashable instead.

And

"Why do they not have a `.sum()` and I have to do `.reduce(0, +)` every time instead."

Or implement it yourself

    extension Sequence where Element: AdditiveArithmetic {
        func sum() -> Element { reduce(.zero, +) }
    }

It is not stuck on a single ecosystem and VSCode has an extension to use Swift in it. The Linux ecosystem is actually getting quite interesting tbh, and they even support embedded targets!