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by NoahTheDuke 1723 days ago
Your post is a lot of fun! I have a fondness for these kinds of deep dives. That being said, I feel like comparing the initial unoptimized Clojure code to highly optimized Common Lisp is kind of unfair. I wonder how fast the Clojure code could run if given the same care. Maybe I'll give that a try tonight!
2 comments
eigenhombre 1723 days ago
That would be great! I agree it's not a fair comparison -- the post was meant more along the lines of, "how far can I push Common Lisp and learn some things?" rather than a strict comparison of performance of optimized code in each language. As I said, Clojure is fast enough for my purposes nearly all the time.
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NoahTheDuke 1722 days ago
I wrote it up here: http://noahtheduke.github.io/posts/2021-10-02-from-elegance-... I'm not a great writer, but hopefully you enjoy it!

I also found a small bug, that you'll want to use `(elt s (+ x 7))`, not `(+ x 8)`. `elt` is 0-indexed, so first and last of an 8 element list will be 0 and 7.

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ludston 1723 days ago
You're going to be severely constrained by the fact that idiomatic clojure code uses immutable data structures which cannot theoretically be as fast as mutable ones in sbcl. Even with transience, the Clojure hash map trie is an order of magnitude slower than sbcl's hash table.
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NoahTheDuke 1723 days ago
Of course. I don't mean to imply that optimized Clojure could match optimized Common Lisp, just that the disparity wouldn't be quite as stark. For truly speed-focused code on the JVM, you have to write speed-focused Java.
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