@U01TLNH6ULD Another option is to have a user.clj file on your classpath (usually in a dev folder which is only added to the classpath via an alias/profile) and have it do that require:

(! 521)-> cat dev/user.clj 
(ns user (:require [clojure.string :as str]))
(! 522)-> cat deps.edn 
{:paths ["src" "resources"]
 :aliases
 {:dev {:extra-paths ["dev"]}}}
(! 523)-> clj -A:dev
Clojure 1.10.3
user=> (str/trim " x ")
"x"
user=> 

Clojure itself automatically loads the user ns at startup, so it will load a user.clj file if present.

How do I access the classpath on a Mac? I found these instructions: "Go ahead and open the *~/.profile* and make sure that the PATH variable is set and includes */usr/local/bin* and */usr/local/sbin*. You should have a line in the file that looks similar to the following, if not add it to the end of the file." but I'm not sure where to find ~/.profile

classpath is not related to shell path (which is what ~/.profile and PATH is about).

~ means "home directory". If you're in Terminal, ~/.profile will refer to your .profile file if it exists.

Alternatively /Users/<yourusername>/.profile if you're after the full path (at least on the version of macOS I'm using).

Ok - I see my Home directory when I open terminal. the "~" refers to this directory?

Correct.

If I use lein, is the classpath set somewhere automatically?

Thank you for that info - I see "~" all the time, and never knew what it meant

You can type

echo $PATH

Thanks

Which instructions are you trying to follow?

https://raphamorim.io/using-clojure-as-cli/

I was just using it to figure out what a classpath was

Hmm, I just installed brew per the HomeBrew home page https://brew.sh/ and then brew install clojure/tools/[email protected]

I don't remember needing to mess with .profile for that -- but my .profile has a lot of additional weird stuff in already...

And this advice is definitely wrong: "Donwload and unzip Clojure" -- that tutorial is a bad one to follow. It's very outdated.

https://clojure.org/guides/getting_started is the best place to start. Lots of tutorials out there are very out of date.

Thanks! You're always so helpful

for example map function produces lazy sequence.

(def x (map #(prn %) (range 10)))
;; => #'user/x
;; no prints
(def x (doall (map #(prn %) (range 10))))
;; 0
;; 1
;; ...
;; #'user/x

the difference between dorun and doall is in the result. former will return nil but later will return collection

what if we have any custom function in map which is not producing side effect? then dorun will be useful?

Without side effects, then dorun will be useless to you unless you want a space heater, as it discards the returned value. The purpose of dorun is to run through a side-effecting lazy sequence without consuming your memory.

doall is also going to be useless with a non-side-effecting function unless you really want the computation to happen immediately to prevent latency when looking up later elements.

doall is very useful when you want to do a for comprehension with side effects.

That helped, Thanks

mount looks good to me. re-render will mount one more time after each code reload. You might also want its opposite:

(defn ^:before-load unmount [] 
  (reagent.dom/unmount-component-at-node (.getElementById js/document "root"))
)

Here is the boilerplate template I use for CLJS projects: https://github.com/athomasoriginal/create-reagent-app

Maybe that can provide some guidance

is there a particular reason you use (defonce start-up (do (mount) true)) instead of just (mount)?

I this scenario, not yet. It’s meant for writing reloadable code. You want to control your side effects and that’s what this does

I add it so that whoever uses this templ has a place to put stuff that should not re-render

Creating a project with the figwheel-main template provides a very similar approach https://github.com/bhauman/figwheel-main-template This is what I use to start my own projects. It sets up some nice build profiles too

I tried this, but for some reason it still connects to the user namespace, that is how I can know that it is connected right (by seeing that it is in the project's namespace)? but even then, if I try (.log js/console "test"), it will say that there is no such namespace js

Ah! You are connecting to a clojure repl, not a clojurescript repl, hence the js ns is not defined. I don’t know how to connect to a cljs repl using deps and figwheel. I use shadow-cljs.

Thanks, I've found the answer. I just had to do cider-jack-in-cljs and choose figwheel-main and it works perfectly, as per the figwheel docs on using CIDER.

hi there!  I'm having the same problem connecting cider to a repl.  I'm following both  and , but it's not quite right!  I can get a repl started from within emacs/cider by running cider-jack-in-cljs, but I can't evaluate forms within the .cljs files which is my main goal.  Any advice?

Try to evaluate (type 1). If it returns object[Number] you have a cljs REPL. If it returns java.lang.Long, it's a clojure REPL.

If it works but you can't evaluate from the source buffer, look at how sesman works with cider. Especially sesman-link-with-buffer https://docs.cider.mx/cider/usage/managing_connections.html

Also remember that a cljs REPL has to be connect to a JavaScript runtime (browser or node)

@U2DART3HA many thanks! My repl does open correctly and links to the browser, with (type 1) returning #object[Number]; also entering (println "test") is reflected in the browser console.log.

This narrowed the problem down to evaluating forms from the buffer holding my .cljs files. This wasn't working. I checked the sesman pages and it helped my understanding, however my brief checks didn't reveal anything obvious.

Next I noticed a warning was showing when I opened .cljs files -- "[warning] something in your configuration activated 'clojure-mode' instead of 'clojurescript-mode' for this buffer. This could cause problems." My emacs configuration is unchanged from the excellent Daniel Higginbotham's https://github.com/flyingmachine/emacs-for-clojure/. I browsed through the config files in my .emacs.d dir (I'm a very basic emacs user so this is a stretch for me!!) and couldn't see any obvious culprits although I imagine there needs to be a clojurescript specific addition.

Embarressingly, all I needed to do in the end was enter m-x clojurescript-mode. I can now evaluate (type 1) in the .cljs file buffer. This works, so even though not "perfect" it will keep me right for now. I'm sure I'll make the minor amendments needed to my emacs config when I become more familiar with emacs. Thanks for your help!

Cider has three modes: - clojure-mode (clj) - clojurescript-mode (cljs) - clojurec-mode (cljc) The default configuration should map each file extension to the corresponding mode. If it doesn’t then probably something is overriding it. If your editor misaligns file extensions and repl types, you might also want to look at cider-set-repl-type. I havent found it in cider doc, but M-x describe-function RET cider-set-repl-type says

Set REPL TYPE to clj or cljs.
Assume that the current buffer is a REPL.

Thanks @U2DART3HA really helpful to know about cider-set-repl-type. Yes, I think I will need to get my default configuration properly set up for clojurescript as well as clojure files. I imagine it could get very complex very fast if I keep using a manual approach, ie entering clojurescript-mode for each and every .cljs file I have open.

We’re using firebase, I guess the config is in there, Thank you