Articles about Swift, Cocoa, software design and programming.
In this article, I'm presenting CwlSignal. It is the latest Swift iteration of a library that I've been using for reactive programming for the last few years. CwlSignal is simple, fast, threadsafe and full-featured while offering a number of unique abilities.
Testing that actions are scheduled correctly over time is a pain. I'll show a way to test events scheduled over time, threads and other execution contexts with a "Debug Context Coordinator" that functions as a basic task scheduler but operates over a simulated version of time so that testing of invocation times and task interaction can be precise and free from changes due to host activity.
I take a look at what's involved in specifying the 'execution context' in which a function should be invoked. It's a complicated task due to how broad the term 'execution context' can be, as well as the fact that both function caller and function callee may have conflicting desires for how a function should be invoked.
Sep 22, 2016
I present an implementation of a a double-ended queue type (deque) in Swift and look at what is required to implement copy-on-write in an optimized way so that this double-ended queue is faster than Array when used as a first-in-first-out (FIFO) queue.
This is a quick look at the changes I needed to make to bring Cocoa with Love up to date for Swift 3 and the latest iOS 10 and macOS Sierra.
A concrete look at the languages studied by the Swift developers when designing Swift's approach to error handling. By comparing these to Swift, I'll try to better understand what balance the Swift developers sought on the topics of feature complexity, syntactic efficiency, abstraction, information signalling and safety.
In this article, I'll discuss the Result type in Swift as well as common variations in implementation and approach used for this data type. I'll also look at *why* the type was rejected for inclusion in the standard library and what effect that rejection is likely to have.
I look at usage patterns around timers including some problematic approaches that can make refactoring more difficult, cause strange bugs and otherwise create problems for maintainability.
Jul 12, 2016
One of the most annoying problems in Swift is when the compiler gives an 'Expression was too complex to be solved in a reasonable time' error. I look at why this error occurs, how to avoid it and talk about how this should be solved in a future compiler update.
Jun 25, 2016
Fun with a pushdown automaton (implemented as a single mighty switch statement) for parsing whitespace in Swift source files. The result is an Xcode 8 Source Editor Command extension for detecting and correcting whitespace issues in Swift files.
