AdventOfCode2022 VS clj-fast

Here are all my solutions.

The same approach as my Python solution — for each row, it tracks the left-most and right-most seen point for each sensor. Then it searches if there has been a gap between two sensors.

In the end, my solution, especially in the game logic part, is heavily based on the stuff you did.

Here is my repo.

Repo: Python and Clojure solutions

But to be honest, I like my Clojure solution even more.

IIRC clojure.core/merge is another needlessly slow implementation that gets used a lot. If you are leveraging that on hot paths you will probably see some benefit in writing your own variant or copying one (or adding a dep) from a lib that is faster. There are some explorations of these ideas in clj-fast with some early results and trends and plenty of interesting discussions in the issues.

Noticed that code compiled in a defn as opposed to raw evaluation of the body at the repl produces different bytecode (and impacts inlining / jit) in some cases https://github.com/bsless/clj-fast/issues/16 . Kind of a cousin to the original issue you raised.

Some interesting exploration in the clj-fast library and discussions in the issues there.

The only other weird performance regression with array looping code is if you test it at the repl vs inside a defined function that's called. Different bytecode emitted in each case for some reason, with the function wrapper version being substantially faster.