does anyone use spyscope with clojurescript? even though I’ve added it to dependencies, the compiler can’t find it when I require spyscope.core. generally what debugging libraries do people like to use? i’m just using lots of prints

@lee.justin.m that reminds me somewhat of https://github.com/vvvvalvalval/scope-capture

I’ve used scope-capture some and have liked it. I used it a pretty basic level, but it was helpful to me for capturing locals environments at runtime

In the CLJS via figwheel + cider + piggieback repl I am getting an “analysis error” “at line 1" with really no information when trying to expand a macro:

----  Could not Analyze  <cljs form>   line:1  column:1  ----

The cljs repl analysis happening here seems opaque and it doesn’t give stacktraces or anything

I'm having trouble making a re-frame app run my init function when I load the page. How can I tell it what it should run first?

I have a function with ^:export metadata but it is ignored

I don't really want to put side-effects in my namespaces

who calls the function?

the point of :export is that something can now call it from the outside - I use a script tag in my shell html that calls the init to start the webapp

(after all the scripts are loaded of course)

and yes, not calling init from the top level of the ns is good - for example that makes testing more straightforward

hello all, what do you use in :optimizations to do not give problems with external js libraries?

@fabrao Anything but :advanced

@conan: Happy to help over in the #re-frame channel

Any tip how to remove the duplication from

(AWS.Credentials.
      (ggo/get creds "AccessKeyId")
      (ggo/get creds "SecretAccessKey")
      (ggo/get creds "SessionToken"))

(apply new AWS.Credentials 
   (map 
       #(ggo/get creds %) 
      ["AccessKeyId" "SecretAccessKey" "SessionToken"]))

right, apply doesn't work with constructors or methods

you can use a macro though

(defmacro make-creds [& sources] `(AWS.Credentials. ~@(map (partial ggo/get creds) sources))

or maybe the ggo/get has to happen in the cljs at runtime, which means constructing it differently

(defmacro make-creds [creds & sources] `(AWS.Credentials. ~@(map #(list 'ggo/get creds %) sources)))

Can anyone point me to an example of code that uses the cljs API (and specifically cljs.analyzer.api/analyze-file) to produce javascript from a cljs file?

@mac01021 cljs.compiler.api/compile-file does that

Thanks @thheller! But is there no way to get JS out as a string without using the filesystem?

you can yes but I don't think there is any official API for this.

what are you trying to do? compiling one file won't work since it will require a few others to also be available

I want to be able to take any cljs file on my classpath and obtain the corresponding javascript as a string (to serve as a web response, most likely) This weekend I very quickly got to the point where I had

(with-core-cljs nil (fn []
                        (analyze-file "us/quartyard/wat.cljs")
                        (println(all-ns)) ;; prints essentially what I expect.
                        (now what???)))

things are slightly more complicated than just serving one file though

to get the actual AST you’ll need the analyze result

analyze-file is mostly about populating the compiler env

But analyze expects a single form, while my namespace consists of a series of forms that should (I think?) all be incorporated into the same JS script.

There's no way to populate the compiler state and then extract the various analyzer results from it to emit the JS for each piece?

not sure what the actual API is but you'd usually open a tools.reader instance, read one, analyze, emit, repeat

interesting.

And then use some other mechanism to emit the JS for the core namespace (which any other script will have to rely on)?

forms-seq should help

things are slightly more complicated since everything has to be loaded on the client side in order

so you can't load one ns without having loaded cljs.core first

That's fine, as long as I can find a way to serve a copy of cljs.core so that the browser can load it

and things get way more complicated when including JS dependencies

I should be able to gather all the dependency cljs files and then analyze/`emit` them all, concatenating all emissions into a single JS file, right?

oh JS dependencies

not cljs dependencies, got it

Ok. I'll give it a shot. Thanks for the pointers!

Is there a spec for javascript datastructures (aka json)?

something like #js [1 2 3]

@escherize For your particular example array? 🙂

derp! 👌:skin-tone-3:

Also, throw in a bit of js/goog.isArrayLike for taste.

🍻 thanks Mike

No problem. That's the precondition used for checked aget, FWIW. https://github.com/clojure/clojurescript/blob/master/src/main/cljs/cljs/core.cljs#L445

now I have another one, I need to check that #js [1 2 3] === #js [1 2 3]. I know it’s not js/==.

ERROR in (get-works) (zzz/api_test.js:86:46)
expected: (js/== n #js [1 2 3])
  actual: #object[ReferenceError ReferenceError: Can't find variable: _EQ__EQ_]

Maybe (= (js->clj a) (js->clj b)) is good enough

@escherize goog.array/equals might fit the bill

^ and ~ 2 orders of magnitude perf boost https://gist.github.com/mfikes/2199d662d89626d26ffde1917acbbf9e

^ In short, avoid js->clj if perf is important