<? macro

macros.clj

(ns app.macros)

(prn "
  I'm trying to write the <? macro mentioned by David Nolan: 
  ... http://swannodette.github.io/2013/08/31/asynchronous-error-handling/ 
  It's my first CLJS macro and I'm not clear on how to write macros 
  in Clojure for ClojureScript.
  ")

; throw-err can't be defined in this file, because there is no `js` namespace in Clojure.
; It needs to be written in ClojureScript, but referenced from the <? macro. ???
(defn throw-err [e]
  (if (instance? js/Error e) (throw e) e))

(defmacro <? [expr]
  `(throw-err (<! ~expr)))