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Comment by narag | Hacker News Reader

I bought this book in paper time ago, put it aside (I bought half a dozen at the same time) and when I finally got to read it, I found out that I had brought the wrong version. Too late to return it...

A question: is any of the currently hot software written also in Lisp? I mean the LLMs, SD, etc.

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Grammarly posted an article a couple years ago about using Common Lisp: https://www.grammarly.com/blog/engineering/running-lisp-in-p...

As someone learning Common Lisp for fun and planning to use it in the web, I’m a little disturbed by the “we manually force garbage collection periodically” part of that article. I haven’t fully digested the commentary, so maybe I’m more concerned than necessary…

> more concerned than necessary.

I would say so, specially when you plan to use it for web dev (welcome!). Shinmera has released a game in CL heavily depending on CLOS (object system), and he says the GC is barely a matter.

https://raw.githubusercontent.com/Shinmera/talks/master/els2...

https://kandria.com/ (https://github.com/Shirakumo/kandria)

https://reader.tymoon.eu/article/413

I recognize your user name. Great work on the Lisp Journey site! Several times I’ve had a question and then found the exact same thought expressed on your site (along with an answer).

That's nice to hear, thanks for the feedback. I've been puzzled many times when starting out (or taking a not-so crowded path), so I'm glad the ones after me are having a better time.

Now, your time to build cool things and share in the process ;)

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(https://lisp-journey.gitlab.io/)

Looks like they wanted to configure a much larger heap than they needed just in case, but then to have the system pretend it doesn't exist, and do GC cycles at a much lower threshold. I'm surprised SBCL doesn't have parameters to be just tuned that way; if not, that could be upstreamed.

Going longer between garbage collection cycles could be worse in terms of caching and paging. Marking the live objects allocated in that generation is about the same, since that doesn't grow, but there is more garbage to visit and sweep. Sweeping a smaller memory area more frequently is going to be faster than sweeping a larger area less frequently, from the point or view of caches and TLB.

(Regarding my remark about live objects; with larger collection cycles, they could be spread in a wider VM footprint, even if their quantity doesn't grow. The image has a kind of "GC working set"; longer intervals mean that there is a longer working set. The data being transformed cycles through more memory locations.)

The corollary question: examples of companies who use CL: https://github.com/azzamsa/awesome-lisp-companies/

If you are interested in machine learning, check out Gabor Melis's library: https://github.com/melisgl/mgl. It's not an area I'm super familiar with, so I can't speak to it's feature set, but I believe he used it to win a machine learning competition some years ago.

I don't think anyone's written a transformer or diffusion model with it, could be a fun challenge.

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