lisp-in-life VS primes-cpp

Still, my favorite has to be the LISP interpreter written in Conway's Game of Life written in LISP.

Almost forgot - Lisp In Life. Pretty sure I first saw that on HN. IMO the more amazing thing is the Life-based processor, once you have that, the rest is a matter of adding layers. But it's one thing to know someone could do it, quite another to see it in action.

https://github.com/woodrush/lisp-in-life

Run it in your browser here. Definitely worth zooming all the way in to get a sense of scale.

https://woodrush.github.io/lisp-in-life/

Everybody mentions this, and what's great is that it is a pretty natural solution to a lot of problems. I remember coming up with a version of it while writing an optimized prime-sieve[1], and was surprised when I later learned that it was some named technique.

In addition to just the basic loop-unrolling (which I'm pretty sure you usually don't need to do by hand with modern compilers), it works really well when you need to jump into the middle of a pattern. Like if you're sieving primes in a wheel-factorized array.

[1] https://github.com/patricksjackson/primes-cpp/blob/master/pr...

  // Here we're only checking possible primes after wheel-factorization