I’m going through the “Clojure for the brave and true book”, and now I’m on the core-async chapter

at the end it gives an example of using channels to create a process pipeline

(def in-chan (chan))
(def upper-caser-out (upper-caser in-chan))
(def reverser-out (reverser upper-caser-out))
(printer reverser-out)

this is nice but my question is, is there a macro or some way to make this more readable?

it just feels to me that this can look more concise

if you don’t need the intermediate pieces:

(-> (chan)
    upper-caser
    reverser
    printer)

sort of like the -> macro?

awesome!

oh would that not work?

are upper-caser, reverser and printer functions?

yes, they take an in channel

then I think that should work

(defn upper-caser
  [in]
  (let [out (chan)]
    (go (while true (>! out (clojure.string/upper-case (<! in)))))
    out))

(defn reverser
  [in]
  (let [out (chan)]
    (go (while true (>! out (clojure.string/reverse (<! in)))))
    out))

(defn printer
  [in]
  (go (while true (println (<! in)))))

since presumably you need to be able to put stuff into the channel:

(let [c (chan)]
  (-> c
      upper-caser
      reverser
      printer)
  ;; put stuff into c here
  )

Does anyone know if there’s a way to do what I’m trying to do here? https://www.refheap.com/117586

Essentially do different work in the macro before actually emitting the output depending on whether it’s generating clojure code or clojurescript code?

(assuming a suitable namespaced-alist->map function)

I just need to replace the *clojure-version* test

@lgastako: thanks for your help!

no problem

is your problem the fact that clojure-version is not bound on the client?

does this help? http://stackoverflow.com/questions/4198549/in-clojure-how-can-i-test-if-a-a-symbol-has-been-defined

well, it’s more that even when generating clojurescript code, the macro itself is executing in a clojure environment (the compiler) and so clojure-version is always bound there… if I reference inside the emitted code then it’s bound/not bound accordingly and works great, but in this case I need to be able to filter out some bits incoming args depending on which type of code is being emitted

thanks, but unfortunately not in this case

I was able to get it working using this if-cljs macro that everyone else seems to use: http://blog.nberger.com.ar/blog/2015/09/18/more-portable-complex-macro-musing