Braitenberg vehicle 2 and 3 - fear, agression, love

See: Vehicles Overview, Fear, Aggression, Love

Making some cybernetic, organismic machine animal simulations using Quil and Clojurescript.

The most canonical Braitenberg vehicles. 2 sensors, 2 motors, ray sources in the environment and different wiring make different behaviour.

I will deploy this soon.

Life coding Emacs, Clojure, Meow, screencast, programming, cybernetics, code, animals, bio computing, braitenberg, vehicles, love, fear, aggression, explore, system theory, control theory, simulation, toy, fun, little animals

Quil first experiments

Probably way too lengthy. You can watch how I spent last Saturday :)

Clojure REPL driven development showcase

The fruits of Clojure I

Making a knowledge base database keyword extractor with open ai chat api.


Primagen was recently checking out Uncle Bobs Clojure post, which did not mention the most important thing about Clojure. Interactive Programming is the big magic word my friends.

Related: Interactive Programming and Lisp overview.

#_(add-libs '{net.clojars.wkok/openai-clojure {:mvn/version "0.9.0"}})
(ns scratch
   [clojure.java.io :as io]
   [clojure.set :as set]
   [clojure.string :as str]
   [clojure.java.shell :as shell]
   [wkok.openai-clojure.api :as api]))

(def api-key (memoize (fn []
                        (str/trim (:out (shell/sh "pass" "private"))))))

(defn make-chat-completion [messages]
  (api/create-chat-completion {:model "gpt-3.5-turbo-16k"  :messages messages}
                              {:api-key (api-key)}))

(defn resp->message [resp] (-> resp :choices peek :message :content))

(def extract-keywords!
   (fn [file]
     (-> (make-chat-completion
          [{:role "system"
            "Extract the most interesting, essential keywords from the text.\n\nYou output edn vector format.\n\nExample: [\"AGI\" \"Timeline\"]"}
           {:role "user" :content "Doc:"}
           {:role "user" :content (slurp file)}])

(defn query [db key]
  (get db key))

(defn assert-keywords [db file extracted-words]
  (reduce (fn [res e] (update res e (fnil conj #{}) file)) db extracted-words))

(def the-db (let [db {}
                  kws (for
                          [file ["/home/benj/notes/20230126T094804--the-joy-of-clojure__clojure_code.org"
                          {:file file :keywords (extract-keywords! file)})]
              (reduce (fn [db {:keys [file keywords]}] (assert-keywords db file keywords)) db kws)))

  (spit "the-knowledge-db.edn" (prn-str the-db))
  (read-string (slurp "the-knowledge-db.edn"))

   (assert-keywords {} "foo" #{:a :b})
   (assert-keywords "foo2" #{:a :c})
   (query :c)))

Keywords: Emacs, Lispy, emacs lisp, livecode, screencast, how to emacs, Clojure, REPL, showcase, openai api, chat gpt, programming, code editor

Advanced cider jack-ins

As answwer to this cider issue on github.

;; jack-in-cmd allows you full control over the command that starts the nrepl server process

(defun my-cider-jack-in-prompt-cmd (jack-in-cmd)
  (interactive "sJack in cmd: ")
   (list :jack-in-cmd jack-in-cmd)))

;; I personally like to def a jack in function in elisp which I have somewhere,
;; for instance the readme of my project or dev.el

(defun ftlm-vehicles-make-nbb-nrepl-jack-in ()
   '(:jack-in-cmd "npx nbb nrepl-server"
                  :project-dir "/home/benj/repos/clojure/vehicles/")))

Keywords: Emacs, Lispy, emacs lisp, livecode, screencast, linux, rice, productivity, scripting, programming, Clojure, Cider, Clojurescript, Nbb, Babashka

Lispy how to to insert single brackets

A frequently asked question when using Lispy is how do I insert single brackets, quotes, parens?

The answer is quoted-insert, wich is bound to C-q by default.

It reads the next character and inserts it, bypassing your current keymap and such.

Keywords: Emacs, Lispy, emacs lisp, livecode, screencast, how to emacs, how to lispy, lispy tips, emacs tips

Repl into production example

Real world show case repl into production. This is the kind of thing where Lisp delivers.

Keywords: Emacs, stumpw, arch, Clojure, Datomic Cloud, AWS, EC2, discord bot, REPL, production, fun with computers

(let [server (nrepl/start-server
                :port 7000
                :bind ""
                :middleware cider.nrepl/cider-middleware
                :handler cider.nrepl/cider-nrepl-handler)]
    (reset! nrepl-server server))

Now we want to make an ssh tunnel to this machine to port 7000 on the server machine


Host support-bot-ec2
     HostName ec2-18-212-83-183.compute-1.amazonaws.com
     User ec2-user
     IdentityFile /home/benj/.ssh/ben-ec2-key-pair.pem
     LocalForward 7000 ec2-18-212-83-183.compute-1.amazonaws.com:7000


Opening the tunnel is as easy as:

ssh -i/path-to-key.pem -L 7000:ec2-X-X-X-X.compute-1.amazonaws.com:7000 ec2-user@ec2-X-X-X-X.compute-1.amazonaws.com where the X vals are your compute instances public DNS.



find instance find rules add inbound rule

failure modes

Network SSH p22: If your addresses are wrong, some error; if your path

to the pem key is wrong, quick auth error

Network TCP p7000: If you open up the ports on the wrong SG or source CIDER, etc., IIRW connection will fail quickly with some error, or silently after a long timeout

nRepl service: If you forget to start your nRepl server on the appropriate port, long timeout IIRW

Fast cider overlays

blazingly fast cider overlays and how I got them.

keywords: Emacs, performance, programming, fun, cider, clojure, eval, ovelays, fast, quick, zappy, blazingly fast


Bobscheme page.

Now I made a thumpnail, woar!

I also figured out that I can share -> embed on youtube. Then the iframe works (see above link).

Real world web app screencast

Adding a google drive list feature to my Clojure, Scittle, Reagent, Reitit app.

Real life Clojure programming. REPL-driven development. Emacs, meow, lispy, Clojure, Clojurescript.

The journey so far:


  • Show practical Lisp and Clojure programming, with Emacs
  • Show Emacs

I want to get good at explaining and showcasing what it means to program Clojure. What is repl-driven development, how to do it and how it presents itself to the mind? (its look and feel).

For instance,

  • evaluating little forms every 10 seconds.
  • Tricks like inline defs
  • Impressive stuff like live coding a whole app.

Currently, I still try out stuff and need to get over the initial awkwardness of making videos.

Frames of mind

I realized I have a completely different communication style when I present vs. when I try to develop. One of the next things to try is to actually present in a video. And then slowly bringing in more live coding maybe.

Role models:

  • The Primagen
  • System Crafters

Date: 2023-06-17 Sat 13:07

Email: Benjamin.Schwerdtner@gmail.com