preach

Yep, it's incredible. What you lose in typing and borrow checking you absolutely gain back in absolute raw power

I'm currently working on a project that uses Tcl as its primary programming language. One of the great features about the Tcl interpreter is that it lets you introspect things like variables and procedures at runtime. You also get the full source code of procedures at runtime, even those that were themselves defined at runtime. Instead of the normal work flow of having Claude make changes, starting up a web service, testing the web service with some Javascript driver code, I instead work through Claude in Chrome and expose a web-based interpreter from within the running web service itself. I can instruct Claude to make changes at runtime and immediately after making that change, the code can be tested by Claude. Those changes can then be dumped to disk and reincorporated back into the base source code I have. Not something you'd want to expose to the wider internet, but it's let me move _very_ quickly and build out apps within minutes.

Which models have you found most take advantage of this kind of capability? Opus 5.5 and GPT-6 Sol and Astra seem to like to minimize their tool calls, blatting out a single edit with dozens of lines of code in it rather than editing a few at a time. And they virtually never use things like the Python REPL, even though they use Python all the time.

It seems sort of wasteful of tokens!

[delayed]

> It seems sort of wasteful of tokens!

This was referring to the LLMs' tendency to blat out hundreds of tokens into a single tool call, not to Clojure.

I don't think I'm missing the point. LLMs don't use Python's REPL because it's not that efficient, while properly built harness will eagerly utilize Clojure REPL if given a chance. Without "blating out hundreds of tokens".

You replied to my remark about the token efficiency of a behavior I've observed LLMs

in lisp the repl is the primary mode of development, you replace functions one at a time and only reload the whole system if you break structure layouts, and even then you don’t really restart the whole process (most of the time anyway, sbcl’s immobile code space is a bit of a pain) - agents can and do things by themselves, unprompted, which look like magic even if you’ve been piloting llms for as long as anyone here. I use gpt 6.1 sol for this, I’m sure opus would handle it perfectly, too.

It's ridiculous how stubborn programmers could be. They'd cling to their beloved Blub paradigms and almost cultishly refuse to accept clearly pragmatic takes, sitting just in front of their eyes.

Of course, there's no tool without flaws. Nevertheless, oh boy, how amazingly practical Lisp-dialects can be in reality (even with all their imperfections), it's just astounding. Sometimes I think maybe it is some kind of ego-defeating stance or whatever, maybe smart programmers just can't believe how the stupidly simple idea of Lisp can ever satisfy their galaxy-sized brains? To me, Lisp is like a boundless sea of incredible idea generation on the spot, turning it into practical reality like some magic. Effortlessly, painlessly, and with joy.

I don't know, maybe I had to go through the pain of learning the intricacies of a dozen different stacks, using them for years, only to discover Lisp later in my life. Perhaps I wouldn't know the difference otherwise?

Just the other day, I was watching a YT video, which I of course fully control directly from Emacs - that is very useful for taking notes. I can mute, pause, speed-up, rewind, toggle subs, etc. All while typing a message, a note, or while looking at a PR diff. I thought, "hmm, floating window would be nice". Without even missing a beat, I opened eca-emacs buffer, I didn't even have to type the prompt - I used speech-recognition. Agent then connected to my WMs REPL, tapped into the mpv, analyzed things on the fly and just built the solution, right there. I didn't even have to compile, restart, reload, refresh anything.

It's almost as if Lisp has been quietly waiting for this moment. LLMs and Lisp REPLs make such a great duo - if you're a programmer and haven't seen it in practice yet, you should seriously be experiencing deep FOMO right now.