Since February of 2026, I’ve been publishing a series of videos on implementing Swish, a Clojure-like Lisp in Swift using Claude Code. You can find it here.
Swish Logo
I used Common Lisp for a solid year in college, and really enjoyed it. I always wanted to use it professionally, but never really had the chance.
In the last few years, I’ve become kind of obsessed with Lisp. I don’t know why, but I keep trying to and wanting to use it in my Swift apps. So, I had written another version by hand, and had made a lot of progress, but stopped because it just seemed impractical.
Then I decided I needed to learn how to use Claude Code and writing a Lisp for Swift seemed like a good project. With AI assistance, I’m more likely to finish it and produce something useful, because creating a language is a lot of work and takes a lot of time.
Lisps are fascinating, in that their syntax and evaluation model are pretty simple, but you can do amazing things with them. That is why Lisp has lasted over 50 years and modern languages still haven’t caught up to them. They are just now getting macros, but nothing as elegant and simple as Lisp macros.
I plan to make Swish something where you can embed an interpreter in your Swift app or you can compile Swish code to Swift and link it into your app. It probably won’t ever replace SwiftUI or even the UI layer, but it could certainly be a good candidate for writing all your apps business logic. Use the Swift SDK for Android project and you could even put it in your Android apps.
It also makes a great extension language for your app in those cases where you want to give your users the ability to tweak the behavior of your app. Emacs is completely built around this idea. It uses is own variant of Lisp (Emacs Lisp) to basically implement the whole application.
On YouTube, please watch it, and if you enjoy it, Like and Subscribe, and comment what you want to see. There’s also a link to support my work and Buy Me a Coffee.