There’s probably a good explanation for this, but I don’t know it.

FWIW, in JVM Clojure ([1 2] nil) returns Execution error (IllegalArgumentException)… Key must be integer

% clj -A:cljs -M -m cljs.main -r
ClojureScript 1.10.773
cljs.user=> (set! *print-fn-bodies* true)
true
cljs.user=> (defn foo [x] (inc x))
#'cljs.user/foo
cljs.user=> foo
#object[cljs$user$foo "function cljs$user$foo(x){
return (x + (1));
}"]
cljs.user=>

oh interesting I was not aware of that, I will experiment with that, thank you!

Oh so that's only how it prints the function, is there a way to access that data?

(to run it through a pretty printer say?)

Oh ... it's literally just calling str on the function itself. So that's all that is needed to get the value. That makes perfect sense but was not at all apparent. Anyway thank you for your help!

I built this a while ago https://code.thheller.com/demos/shadow-grove/

on the right there is a JS Code tab to show the generated code

not its primary purpose but might help

I’d rather not use reader conditionals if possible since that will fail when connecting to older Clojure systems.

How hacky do you want to be? For example (mod 5 0) throws an error in clj but returns NaN in cljs.

Haha, I’d rather not be hacky if possible 🙂

The NaN behavior is in the docstring too. So this isn’t undocumented behavior.

Sure, but I don’t care about that distinction as much. This is for Cursive, so e.g. I don’t want to be setting things like locals clearing for CLJS REPLs.

I also need to detect Babashka as a REPL server type, so things like the mod hack start getting very fiddly very fast - I’d rather something a bit more definitive like *clojurescript-version* if I can make it work.

Would (resolve 'cljs.core/*clojurescript-version*) not work? Seems to work in my repls. Returns nil in clj and something in cljs

Hmm, you’re right, I’d swear I had tried that.

Ohhh, you know what? I did some initial testing using an in-browser CLJS REPL, and that doesn’t work there. But I think I can live with not supporting self-hosted CLJS for now.

That does work in Planck and Lumo, though - maybe http://clojurescript.io is funky for some reason.

Yeah, it fails in http://clojurescript.net, too. Still, I’m not too worried about that, I think we have a winner. Thanks!

don't use those pages. they are severely outdated and do not reflect the current state of CLJS

one quick way to test would be just (str #'assoc)

(str #'assoc)
=> "#'cljs.core/assoc"

(str #'assoc)
=> "#'clojure.core/assoc"

or work on the var directly but not sure they have the exact same API in CLJ/S

any core var you know exists in both dialects is fair game of course, doesn't have to be assoc

CLJS will always have cljs.core as ns

Interesting idea also, thanks!