Hey y'all, gotta fresh toy here for ya: Kanaka's latest Mal over WASM, ported to ClojureScript and using tau.alpha for blocking reads, running in a browser REPL, producing a Mal REPL: Malhala https://github.com/johnmn3/malhala

i'm looking for a presentation of figwheel and reagent where you could follow along as tetris was implemented. does anybody have the link? i can't find it anymore 😕

found it! http://shaunlebron.github.io/t3tr0s-slides/#0

yeah, that one is amazing

Has anyone worked with Klipse as a library? I want to have some live-rendered snippets of reagent (as part of an interactive tutorial), but I want to call Klipse as a library from ClojureScript. Is this even possible?

if you find out, let me know, I’ve been meaning try this too

It’s tricky, because Klipse needs self-hosted CLJS, but I want the tutorial to be able to seamlessly reuse whatever lies around in my project which is compiled by shadow. I might have to look into actually using files…

Just watched the talk “functional programming in anger”, where David said that now you could require any npm lib, and there is no need to write externs manually. That’s cool. But I can’t figure out how to actually do this. Can someone please provide an example? Should you use foreign-libs, npm-deps, infer-externs etc? Also it would be awesome to include this into get started tutorial.

@romantsopin I think he was referring to https://clojurescript.org/guides/webpack and https://clojurescript.org/guides/externs

lol, can someone help, I've been up for a thousand years. what's the best way to just get a pretty print formatted string in cljs

so I have some json, I want to edit it in a textarea in my browser, and I want it to be pretty printed

(with-out-str (clojure.pprint/pprint the-thing))

oh json, you could convert it to clj first with js->clj

oh huh

if you want to edit it as json, I don’t know. you could look for some existing react lib for it, or use codemirror, I don’t know

still now what I'm going for

doing the pprint thing seems to just be adding escape slashes

@idiomancy if you just want pretty printed JSON and not EDN you can just use (js/JSON.stringify (clj->js {:some "data"}) nil 2)

no i mean its already json

but its like, I want it to look like this (I pasted it into an IDE and used the auto-reformat and pasted it back)

but instead, it looks like this:

(js/JSON.stringify the-json-obj nil 2)

whoa!

hey

look at that!

nil 2

I never knew you could pass additional args to stringify to control the formatting

the magic words

How do you require namespaces in cljs REPL? I tried (require '[my.namespace :as x]), but x/.... doesn't work.

should work

have you changed anything after the first load? then you could try: (require '[my.namespace :as x] :reload)

so here’s a good one: how do you convince someone who doesn’t know what they don’t know (and is convinced they’re right) to look into clojurescript when “nah man i dont like abstractions over raw js” is their line of thinking? react/redux “is the best thing” and re-frame is just silliness.

what do they value?

for example, I came from the react/redux world into Clojure(Script) because I was exploring things that were already being talked about by the people I respected in those communities: - immutability - hot reloading - new syntax

when I started trying out Clojure, it was because I had tried and struggled with those 3 things and had heard that Clojure(Script) had them all by default 🙂

essentially it was easy to do the things I valued + had found hard

but those values didn’t come from Clojure… I already had them from listening to Dan Abramov, Jordan Walke, etc.

well, presumably immutability because they keep the mental overhead of using {... spread, a: 1} syntax everywhere. or they use immer/immutablejs. they have a lot to setup to get hot reloading, but admittedly you usually only have to do that once. it’s like im missing a piece to make it “click”.

for them things like javascripts object equality by reference instead of value isn’t a problem 😞

I mean, for most people it isn’t. you might think it is, but to them you’re just inventing problems 😛

maybe if you related that to componentDidUpdate and having to use immer/immutablejs. I can’t imagine someone using immutablejs in anger and not wanting to burn their project to the ground.

it sounds like this person is happy. are you trying to convince them for some reason?

I’ve been through this recently @lwhorton. I think it’s impossible, because the things ClojureScript brings to the table manifest over a longer period of time, and they also require a considerable up-front investment. So people who feel productive in their local maximum are reluctant to change.

One argument I had is that Clojure incorporates into the language many concepts that in JS you need to have a framework for. E.g. the succession model with atoms that can replace redux entirely. Also a standard library.

In the end, it feels like you’re in a Monty Python sketch arguing about what the romans ever did for us.

one tactic I've used with a bit of success in that argument is to rebuild something - and not just a prototype, but a full reimplementation of some part of the app, real data and all - and then show (1) how much smaller and simpler the code is, and (2) how much more quickly I wrote it. the conclusions are either that these proposed tools are more powerful and allow us to do more with less code in less time, or that I'm way smarter and more productive than whoever wrote the original code, which seems unlikely.

both arguments fall apart if there's even one footnote on the reimplementation; it needs to be real.

because if there's even one tiny crack, it will become the explanation for everything, rather than the language.

(even if it's completely impossible for the tiny crack to cause the four-fold code size reduction, etc. etc. you can probably hear how many frustrating and circular arguments we had about this.)

(caveat, for honesty: I failed to ultimately persuade my team. there was an irredeemable "crack": Javascript is an officially supported language inside Google, and ClojureScript is not. never mind that both go through the Closure compiler and ultimately result in Javascript code for the user's browser to run.)

but I had converts, which is something.

@lwhorton I typically express shock along with a disingenuous attempt at empathy for those using raw js. OMG you actually live without core.async?

Hi, I'm trying to compute a d3 pack layout from some cljs data. It works quite well, but when I convert the result back with js->clj, I just get #object[Node [object Object]]... Any idea how to turn that into useful data again, or do I have to recurse through it myself?

json.stringify works on it, after I removed the parent field from it, which otherwise makes it circular -.-

define multimethods in runtime is a bad thing to cljs? example

(defmulti foo ...)
(defn main []
  (defmethod foo ... ))

@souenzzo any kind of runtime usage of def is discouraged

we certainly don't check for problems you might encounter doing that and don't have plans to

the one exception here is wrapping defs in some kind of conditional feature detection

but that's not def in def

defmethod is just sugar over (-add-method foo :val (fn [...] ...)) so you could use that directly instead too. defmethod doesn't actually def anything so I'd say its fine.

but imho its probably a code smell if you do that because you need access to extra state in the function definition. something that should probably be passed as an arg

well I would argue the problem here is unmanaged manipulation of global state - def and defmethod both do that - so I'd still argue probably not fine 🙂

unless you're doing something special that really calls for it anyway - I would avoid the pattern

Is there any guides on using ClojureScript’s browser events API? I found wrappers https://github.com/clojure/clojurescript/blob/master/src/main/cljs/clojure/browser/event.cljs but haven’t been able to locate any API docs

@jayzawrotny that ns exist primarily for historical reasons

just use Closure Library directly, goog.events etc.

Ah ok, thanks!