dustingetz

(ns contrib.ui.remark
  (:require
    ;["@hyperfiddle/remark-generic-extensions/lib/browser.min" :as remark-generic-extensions] ; works in node
    [clojure.set]
    [clojure.string]
    ; Refrain from contrib imports so this is more suitable for userland
    [goog.object]
    [prop-types]                                            ; used as js/propTypes.object
    [reagent.core]
    ;[remark] ; works in node

dustingetz

References — Electric Clojure

Electric Clojure implements a form of arrowized continuous time dataflow programming with extensions for network-transparent function composition.

• The Haskell School of Music: From Signals to Symphonies (2018) — best starting point and also a great intro to Haskell.
• The Essence of Dataflow Programming (2006) great category theory overview of dataflow programming; missing Applicative (2008), Free monad and Cofree comonad
• Push-pull functional reactive programming, Elliot (2009)
• Breaking down FRP, Jane Street (2014) — good concise comparision of many FRP aspects; missing discussion of discrete vs continuous
• [Compiling to Categories, Elliott (2017)](http

dustingetz

Multiplayer chat with presence – Electric Clojure

• 60 LOC: demo_chat_exdended.cljc

20230131.presence.edited.mp4

dustingetz

Missionary concept map

Missionary primitives fit into three categories:

Effect descriptions = pure functional programming which is about trees not graphs

• continuous flow, m/?< (switch)
• m/watch, m/latest, m/cp
• m/observe
• m/reductions, m/relieve

dustingetz

PostgreSQL hello world — Electric Clojure

How do I integrate a SQL database backend?

Easy:

• make an ordinary Clojure function query-pokemon-list for the query
• The query is blocking, and Electric Clojure is async, so use e/offload to move it to a thread pool.
  • (Don't block the event loop!)
• e/offload throws Pending until the query finishes, and then the exception "goes away"

dustingetz

Datomic web explorer

• Client API, tested on Datomic Cloud
• database entity browser
• server paginated infinite scroll
• streaming information model - displays incremental resultsets as they become available (useful for slow queries)
• automatic backpressure and cancellation of abandoned queries
• custom web renderers with dynamic queries

Code is not optimized yet – we are still learning the idioms.

dustingetz

HOWTO install #user/uri reader extension in Clojure/Script

We use #user/uri rather than unquaified #uri per Alex Miller comment in the Ask Clojure thread.

License: public domain

dustingetz

(defmacro future
  "Takes a body of expressions and yields a future object that will
  invoke the body in another thread, and will cache the result and
  return it on all subsequent calls to deref/@. If the computation has
  not yet finished, calls to deref/@ will block, unless the variant of
  deref with timeout is used. See also - realized?."
  {:added "1.1"}
  [& body] `(future-call (^{:once true} fn* [] ~@body)))
​
(defn future-call

dustingetz

List of Photon demos and content

Photon is a network-transparent Clojure/Script dialect for full-stack web application development. It uses macros to let you interweave client and server code in a single .CLJC file, so you can define a full-stack frontend/backend webapp all in one place. Photon is designed for stateful full-stack web applications with complex frontend/backend data sync requirements.

Newest demos:

• Datomic web explorer (Oct 2022)

Personal favorites:

• Photon infinite scroll over node_modules v2

dustingetz

Datomic database transaction browser coded in Photon, by nottmey

This fullstack web app is 239 LOC in a single file, coded with just fns in the straightforward/easy style of PHP. All client/server I/O is managed!

It took him 10 hours. Thank you Malte! #Clojure

20220529.Photon.Datomic.Viewer.-.Malte.Nottmeyer.mp4