Swift (Day 1) - Ecosystem, Language Primitives, Resources

I wanna make an app. iOS for starters (it's what my friend and I have). Have several ideas, have friends with several ideas. Wanna blog about the process, so here we go.

• Ecosystem: XCode + Swift + SwiftUI.

  • XCode is a nice IDE so far - a lot of shortcuts map over from my IntelliJ experience, and the auto-compiling preview functionality + different compilation targets has been smooth and transparent.

  • I'm not gonna mess with UIKit at all.

  • I'm sad that Android uses Kotlin, I wanted to learn Kotlin. But both ecosystems are fairly locked, what with Android being a Kotlin + Jetpack Compose world.

  • Cross-platform builds seem crippled by the usual suspects - lack of investment from the native platforms, complex access and abstraction to native primitives, native performance greatly exceeding cross-platform, etc. Options include Dart + Flutter (also from Google), and Kotlin Multiplatform. For now, I'll stick to the native platforms.

• Language Primitives: Swift has a lot of them! This is a really "feature-rich" language - I'm gonna miss Go. Some ones that have stuck out:

  • Multiple initializers (designated, overloaded, convenience)

  • Extensions (like Scala's implicit classes, it seems)

  • Internal + external function argument names (a new one for me, not sold yet)

  • Guard statements (safe unwrapping is nice)

  • Protocols (composable + inheritable, embedded generics via associatedtype)

  • Structs AND classes (small differences)

  • Actors, async / await, queues too

  • Attributes galore (@MainActor, @inlinable, @preconcurrency, @frozen etc.)

  • So many ways to modify access, concurrency, optimizations via properties / access control (things like nonisolated, fileprivate, static, etc. -- they all map to relatively sane, known concepts, but yeesh).

• Learning: good resources so far.

  • ChatGPT-4o is my first line of inquiry for exploration. Super useful so far.

  • The Swift book seems well-done.

  • Apple has good resources including tutorials.

    • I've started with the Develop with Swift tutorial - lots of basics, but well-done.

    • Swift Playgrounds are useful for a lot of sample apps.

  • The Exercism #48in24 challenges will be good for brushing up basics (with Golang too!).

  • I found some Swift repos I want to use as references, listed here.

  • This list of open-source iOS apps will be useful for perusal; filter for most stars with "swiftui" tag:

curl -o apps.json "https://raw.githubusercontent.com/dkhamsing/open-source-ios-apps/refs/heads/master/contents.json"

jq '.projects | map(select((.tags | index("swiftui")) and .stars != null)) | sort_by(-.stars)' apps.json > filtered_apps.json

Lots to learn and do! Let's see how this goes.