gistfile1.txt

; my basic attempt at doing core.async in clojurescript adapted from
; http://rigsomelight.com/2013/07/18/clojurescript-core-async-todos.html
;

; project.clj
(defproject jsa "0.1.0-SNAPSHOT"
  :description "FIXME: write description"
  :url "http://example.com/FIXME"
  :license {:name "Eclipse Public License"
            :url "http://www.eclipse.org/legal/epl-v10.html"}
  :dependencies [[org.clojure/clojure "1.5.1"]
                 [org.clojure/core.async "0.1.0-SNAPSHOT"]
                 [org.clojure/clojurescript "0.0-1859"]
                 [jayq "2.4.0"]]
  :plugins [[lein-cljsbuild "0.3.2"]]
  :cljsbuild {:builds [{:source-paths ["src/cljs"]
              :compiler {:pretty-print true
                         :output-to "resources/public/compiled.js",
                         :externs ["resources/public/jquery-1.10.2.js"]
                         :optimizations :simple}}]}
  :repositories {"sonatype-oss-public" "https://oss.sonatype.org/content/groups/public/"})


; jsa/core.cljs
(ns jsa.core
  (:require [cljs.core.async :as async :refer [chan put! <! go]]
            [jayq.core :refer [$ append ajax inner css $deferred
                      when done resolve pipe on bind attr
                      offset] :as jq]))

(.write js/document "<p>Hello CLJS world!</p>")

(defn click-chan
  [selector msg-name]
  (let [rc (chan)]
    (on ($ "body") :click selector {}
        (fn [e]
          (jq/prevent e)
          (put! rc msg-name)))))

(defn app-loop []
  (let [in-chan (click-chan "a.click-me" :got-click)]
    (go
     (loop [count 1]
       (when-let [msg (<! in-chan)]
         (.write js/document (str "<p>Got " msg " click-" count "</p>"))
         (recur (inc count)))))))

(app-loop)

; brower console

Uncaught Error: Assert failed: <! used not in (go ...) block
nil compiled.js:14625
cljs.core.async._LT__BANG_ compiled.js:14625
(anonymous function) compiled.js:16457
jsa.core.app_loop compiled.js:16464
(anonymous function) compiled.js:16466

; analysis
;
; my only explicit use of <! is in the app-loop function and within a (go ...) block.
;
; searching I came across: http://martintrojer.github.io/clojure/2013/07/17/non-tailrecursive-functions-in-coreasync/
; which seems to be saying that core.async can handle loop/recur forms.
;
; i'm left rather puzzled but my experience of clojure, clojurescript, and core.async is minimal so far ... probably
; i've done something stupid. any help much appreciated.
;
; matt