i'm pretty sure there's a way to have a in-browser repl (e.g. in a popup window , with some limited backward scrolling ability) , to use with a in-browser clojurescript app .. but i'm having difficulties finding one... any good suggestions ?

(def name  (reagent.ratom/atom "Bear"))

(defn ask-for-forgiveness
  []           ;; <--- no props     
  [:div "Please " @name " with me"])   ;; notice that @

How does reagent knows which function to re-render when the depending ratom changes ?

it records derefs when converting hiccup -> react elements

Hello! who has an ide why this custom CLJS reader does'n work for me:

(ns ok.ok)

;; #js-object-record                                                                               
(defrecord JsObjectRecord
    [type data-map]) 

(defn js-obj-read-fn [arg]
    (println "reading function-----" arg (type arg)))

(cljs.reader/register-tag-parser! 'ok.ok/JsObjectRecord js-obj-read-fn)
(cljs.reader/read-string "#ok.ok/JsObjectRecord [1 2]")
(println (cljs.reader/read-string "#ok.ok/JsObjectRecord [1 2]"))

depending on which CLJS version you are using it might expect a string

(cljs.reader/register-tag-parser! "ok.ok/JsObjectRecord" js-obj-read-fn)

Huh. I'm trying it in my own namespace and it fails with No dispatch macro for h.. h is the first character in that namespace.

then you have the version that requires a symbol ...

I forgot which version that was changed but it was a breaking change

Yeah, I did use the symbol version. But it seems that a tag parser cannot return nil.

If I return nil it thinks that that's not a tag and tries to parse it as a dispatch macro.

hmm yeah dunno about that part

I use [org.clojure/clojurescript "1.10.597"] and for example this code works:

(cljs.reader/register-tag-parser! 'foo identity)
(cljs.reader/read-string "#foo [1 2]")

but for some reason when I namespace the symbols it stops, even if the namespace is already present (I created one just for the sample)

I just found out that the reading function is the problem - when I use identity it all works, but any function made by me drops that exception

hey people!! has anyone ever managed to play with cordova + cljs please ? I would be interested in some documentation on how to get them to work together!thanks in adv

the translation of foo.init().then(function(z) { z }); would be (.then (.init foo) (fn [z] z)) right?

yep

yep. Apparently the api returns some other thing that isn't a promise if you don't tell it to. A "librarly specific object". cool.

I am trying to have some calculations work out exactly the same between Clojure and Clojurescript, and the different implementations of numbers are biting me. Are there any libraries or quick fixes for this? Otherwise my first thought is to make my own 'Ratio' type and math functions to use cross-platform.

I feel like that question is going to be a rabbit hole 🙂

If it makes thinks any better, I don't have to mess with how numbers work everywhere they might be used in clojurescript, just in a limited 'scripting' scope I have total control of.

Often told JS isn’t multithreaded, but is anyone looking at bringing more over into CLJS utilizing Worker threads?

workers can't share memory so they aren't super useful for most stuff

in the shadow-cljs UI I moved all data processing to a worker and the "main" thread just queries it like a db. works ok but the tradeoffs are kinda annoying

Once I made a game where I tried moving the physics to a webworker, but it cut FPS from 60 to 20. Having to serialize everything all the time means it is useless for a lot (maybe even most) use cases.

will be cool if workers + wasm threads get to some point where we could pass immutable objects without serializing

yea, exactly

another big limitation is you cannot do DOM measurements in a web worker

I don’t know much but my first thought is that will always be impossible to do without coordinating with the main thread

well for example on other platforms, it is not problem to measure the size of a text with a certain font on a background thread. No reason one shouldn't be able to do the same in a web worker. I could see limiting which thread can modify the DOM, but what about DOM objects that are just in memory, not rendered on screen?

Is this something not shared on the browser? > Unlike child_process or cluster, worker_threads can share memory. They do so by transferring ArrayBuffer instances or sharing SharedArrayBuffer instances.

AFAICT SharedArrayBuffer is caught in limbo right now and isn’t supported by many browsers

So Node has actual shared memory but many browsers do not

doesn't seem like the most useful form of shared memory anyway