One of the best things of modern Swift is the introduction of KeyPath. It allows us to reference getters and setters as first class values in our code. With them you can simplify a bunch of code and make it less error prone. In this post I’m gonna evolve the groupBy function from GroupBy in Swift 2.0 to use this new functionality.
I discovered the Advent of Code from some retweet on the first days of December. I found them really interesting and original so I decided to give them a try. I know, they’re just programming exercises but they’re written in a nice story driven way!
I’ve always been a big fan of Linked Lists. Maybe is because it was one of the first data structures that I learn how to implement and they were my introduction to the fascinating world of pointers. Nowadays I hardly think about pointers in my daily work. In Objective-C you just treat them as the objects you want to message with, and in Swift the lovely * has disappeared. But I still feel nostalgic sometimes.
Getting C-level performance in Swift for numerical algorithms is quirky but not particularly difficult. If you limit yourself to value types (no classes or existentials), use unsafe pointers and tuples instead of arrays, use overflow discarding operators &+/&-/&* instead of normal +/-/*, use while or repeat/while for your loops, then Swift and clang C will generally compile to identical instructions.
I really recommend reading how Maxim made his FlatBuffer library 10 thousand times faster Swift.
The other day I had some spare time and I started exploring the idea of a Stack in Swift using protocols. For what? For fun.
2018/08/23: A new version of this post is available. Using KeyPath to simplify the call site and reduce possible mistakes.