01 Field notes

Thinking,
made visible.

Swift, architecture, Apple-platform internals, and the small product decisions that make software feel considered.

02 Latest essay

January 3, 2019 11 min read

Using a C file in a Swift Framework: an exploration

The problem While building a diagnostics tool, we shipped it as a single Pod containing only pure Swift code. The Swift code needed to call into a few system C library features — specifically, resolv.h from the …

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06 Testing Swift code that uses system singletons in 3 easy steps Original: Testing Swift code that uses system singletons in 3 easy steps Original author @johnsundell Most apps built on Apple platforms lean on … Jul 2018
07 Avoiding singletons in Swift Original: Avoiding singletons in Swift Original author & Copyright @johnsundell “I know singletons are bad, but…” — you hear it all … Jul 2018
08 Different flavors of dependency injection in Swift Original: Different flavors of dependency injection in Swift Original author & copyright: @johnsundell In previous posts we’ve looked at … Jul 2018
09 My favourite Mac apps A running list of the Mac apps I reach for. Every time I reinstall macOS, I forget to grab one or two of these and only notice once I actually need … Jul 2018
10 What is LLVM What is LLVM? The secret behind Swift, Rust, Clang, and more Understanding how a compiler emits native machine code makes it dramatically easier to … Jul 2018
11 In-app purchase If your app ships on the App Store, in-app purchase (IAP) is something you can’t really avoid. Last year’s spat between WeChat tipping and … May 2018