Inline Code Commentary

The code shown herein will only compile and link in Xcode 10 beta and run on iOS 12 beta and/or OS X 10.14 beta.

While working on a Swift protocol-oriented and generic linked list, I got to thinking about Apple’s “improvements” to version 4.2 of their flagship language. Since a linked list is a list, I thought, “Why not add a subscript to my linked list to facilitate finding specific nodes in my list?” I did that in Swift 4.1 and got what most developers would’ve expected, e.g., used linkedList["node4"] to get the node in the list associated with the keyword “node4.” With Swift 4.2, I can use the controversial new @dynamicMemberLookup language attribute and implement dot/member notation, like linkedList.node4 to get that same node in the list associated with “node4.” Big improvement, huh? Well, maybe. We’ll talk about how this new and improved subscript is more than just about syntactic sugar, but that the “driving motivation for this feature is to improve interoperability with inherently dynamic languages like Python, Javascript, Ruby and others.” Note that all code shown in this tutorial was written in two Xcode 10 beta playgrounds.

Continue reading “Swift 4.2 improvements? Member/dot syntax for subscripts. Trying it out in a protocol-oriented, generic linked list.”

Let’s talk about creating understandable and maintainable code in Swift 4, code that can be easily read by other programmers, can be readily debugged, can be reused, and can be enhanced and extended in the future. We’re going to limit today’s discussion to: 1) how best to come up with good names for functions and how best to name their arguments, parameters, and argument labels, and 2) how to use meaningful and descriptive variable (var) names — and constant (let) and enumeration (enum) names, etc. The goal is to create code that reads as to close to English as possible.

You may believe that this topic is overly simplistic or pedantic, but sometimes it’s the “little things” in life that really matter — especially when you have applications that are made up of millions of lines of code, made up of “little things” like function definitions and function calls.

Continue reading “Writing expressive, meaningful, and readable code in Swift 4”