Clojurians Log v2

Anyone run into an issue where a :cljs reader conditional doesn’t fire on a build targeting the browser?

(defmacro dbg!
  [& forms]
  (let [f# #?@(:cljs [cljs.analyzer/*cljs-file*]
               :clj  [*file*])
        md# (meta &form)]
    `(let [res# ~@forms]
       (println (str res# " in " ~f# " line " (:line ~md#) " column " (:column ~md#)))
       res#)))

Macros do run in clj; they run at compile time.

there's some details here https://code.thheller.com/blog/shadow-cljs/2019/10/12/clojurescript-macros.html though nothing about this specifically.

I can't find the reference I'm looking for. but basically you can write code that runs at macro execution time that checks whether you're building for CLJS or CLJ, and can emit different code. but you can't use the reader macro #? syntax inside a macro.

Ah, interesting!

> (defmacro foo [key value] > (if (:ns &env) ;; :ns only exists in CLJS > `(cljs-variant ...) > `(clj-variant ...)) That perfectly solves my problem! Thanks a lot.

Oh wait actually it’s not working in cljc

In java clj

@jayzawrotny Also see https://github.com/cgrand/macrovich

Is it possible to create asynchrounous transducer?

Ok. It seems not possible after few tests 😛

Just checking something after watching some of @mfikes’s inferencing talk at Clojure/north last year… There’s a reference to hinting return types by adding metadata to the function, via:

(defn ^string f [x] (str "prefix" x))

(defn f (^long [] 42) (^String [x] (str "prefix" x)))

(defn ^long foo [x] (str "prefix" x))  ;; type hint is a lie
=> (+ (foo :x) 1)                      ;; but it hides the warning
"prefix:x1"

(defn bar ^long [x] (str "prefix" x))
=> (+ (bar :x) 1)
WARNING: cljs.core/+, all arguments must be numbers, got [string number] instead at line 1 <cljs repl>
"prefix:x1"

https://www.clojurescript.org/about/differences#_hinting

> Type hinting is primarily used to avoid reflection in Clojure. In ClojureScript, the only type hint of significance is the ^boolean type hint: It is used to avoid checked if evaluation (which copes with the fact that, for example, 0 and "" are false in JavaScript and true in ClojureScript).

I was following through on this because of Mike’s talk on type inferencing in ClojureScript, which is more recent work. You can see in the example I provided how this is used for checking the arguments to cljs.core/+

😳

Hello Everyone, I am new to Clojurescript, I have a shadow cljs application with Helix. Currently, I am having trouble while trying to add google recaptcha to the application. Any suggestions or guide would be appreciated

@singhamritpal49 you probably won’t find a guide. If you explain your problem, someone might be able to help you fix it