I didn't get his cljs + rollup reference, what was he trying to say there?

that rollup is better than webpack at tree shaking?

Since JavaScript is single threaded (aside from workers) is there any difference of atom from volatile! ?

@heefoo yes. volatile! has no support for metadata, validators and watchers. if you don't need those, using it instead of atom will save a few memory bytes and a couple of predictable branches on assign

@leonoel thanks.

Hi! I'm having a ton of trouble getting a CIDER REPL to work with Figwheel in Spacemacs

Can someone recommend a best tutorial for setting this up, with working code examples? It seems like the Figwheel and CIDER docs are both slightly out of date and refer to each other for updates.

Even a working project.clj file would be great!

can you explain what you’re having an issue with specifically?

if you have configured figwheel correctly, you should be able to just cider-jack-in-clojurescript ( SPC m " by default) and pick figwheel and the name of the build you want to run

So: I cider-jack-in-cljs

And it appears that the REPL will start, and then I select either figwheel (old docs?) or figwheel-main (new docs)

are you using lein-figwheel?

Yeah, I believe so. My project file is here: https://github.com/kellyi/reagent-leaflet-sandbox/blob/master/project.clj

When I do Ctrl-C, Ctrl-K, it tells me that no REPL exists

Essentially I'm trying to replicate what I do in a regular Clojure CIDER thing which is... I have something like (+ 1 2) written in a file and I can ctrl-c ctrl-k to eval it

does it create a cider and nrepl buffer?

Let me check

you might even want to remove nrepl & piggieback from your dev dependenciesj

using cider-jack-in-cljs should inject the appropriate CIDER dependencies for you

Interesting. Ok, I'll try that out -- most of this was autogenerated from a lein template for a reagent frontend, so there's still some pieces I don't understand.

So it looks like it started a working CLJ CIDER REPL

And then there is another buffer that says "nREPL server started on port...." but is non-interactive

have you loaded your CLJS app in a browser?

wait, is there a CLJS and a CLJ CIDER REPL?

Yeah, and I see the figwheel REPL in the tmux pane in which I did lein figwheel

wait you did lein figwheel?

if you’re running figwheel already, then you’re not going to run cider-jack-in-cljs

Yeah, was that a mistake? That is how I've typically been starting the app

Oh okay. What am I supposed to run instead?

nothing. cider-jack-in-cljs should start figwheel for you

Interesting. Ok, so the CLJ REPL is coming from lein probably

you can connect remotely to the running lein figwheel process if that’s preferable. but they are separate workflows

Got it -- that makes sense

So I'll retry by not starting figwheel from the terminal, but doing cider-jack-in-cljs

! that totally worked. Thanks for explaining this!

🙂 sure thing! what cider-jack-in-cljs does is (when in a leiningen project): 1. Starts a Clojure REPL via leiningen, injecting piggieback and nREPL dependencies 2. Starts figwheel for building your app 3. Uses piggieback to inject the ClojureScript REPL with the build that you want into the Clojure REPL started in (1)

Awesome! That makes sense to me. Thanks again for all your help with this! I've been wanting to show off the REPL development with Reagent but couldn't figure out how to get it to work like it was in a Clojure project.