I have never used Swift, but I can confirm that writing a Lisp is a lot of fun in something like C or Go. I especially like the fact that you can build in so much raw power by implementing Lisp macros for example.

Take it a step lower and do one in assembly and it is even more fun. I almost have enough code together to say that I'm doing one in RISC-V assembly. At this point I have already accidentally picked up a more intuitive understanding of how a lisp compiler works.

https://github.com/marcpaq/arpilisp