ithayer

// Demonstration of how easy it is for this to mess up your loops.

var txt = ["a","b","c"];

for (var i = 0; i < 3; ++i ) { 
   var msg = txt[i];
    setTimeout(function() { alert(msg); }, i*1000);        
}​

// Alerts 'c', 'c', 'c'

ithayer

# Should enable the little battery icon.
xfce4-power-manager

echo "Setting middle button emulation"
xinput set-int-prop 12 "Evdev Middle Button Emulation" 8 1 

echo "Turning off dual mode video"
sudo sh -c "echo OFF > /sys/kernel/debug/vgaswitcheroo/switch"

echo "Turhing off bluetooth"

ithayer

;; Start of what the above flow in clojure would look like.

;; Tokenization step.
(->> (clojure.string/split (slurp "/tmp/X") #" ") tokenize-word)

;; For debugging, just look at the first 100 words...
(->> (clojure.string/split (slurp "/tmp/X") #" ") tokenize-word (take 100))

;; or, look at some in the middle...
(->> (clojure.string/split (slurp "/tmp/X") #" ") 

ithayer

;; Install dependencies
lein deps 

;; Build my ClojureScript.
lein cljsbuild once

;; Start me listening on port 8888.
lein run

ithayer

;; All the visitors to my site.
#> (->> (all-visitors) count)
1000
;; Which browsers?
#> (->> (all-visitors) (map :browser) frequencies)
{:ie-10 50 :ie-9 250 :ie-8 200 :firefox 140 :chrome 360}
;; Average spend?
#> (let [spent (->> (all-visitors) (keep :spend))]
      (/ (reduce + spent) (count spent)))
123.12

ithayer

;; Simple mean function.
#> (defn compute-mean [xs] (/ (reduce + xs) (count xs)))

;; Check the average spend for firefox.
#> (->> (all-visitors) 
        (filter #(-> % :browser (= :firefox))) 
        (keep :spend) 
        compute-mean)
100.2

ithayer

;; Create a function that given visitors, computes 
;; the spend for each - here, just a random number.
user> (defgraphfn spends [raw-visitors] 
        (map (fn [_] (rand-int 10)) 
          raw-visitors))
#'user/spends

;; Create a function that given visitors, computes the 
;; browser for each - here, just randomly assigned.
user> (defgraphfn browsers [raw-visitors] 

ithayer

;; Update our 'browsers' function to print when it's run.
user> (defgraphfn browsers [raw-visitors] 
        (println "Running browsers on" (count raw-visitors) "visitors")
        (map (fn [_] (rand-nth [:chrome :firefox :ie-9]) )
          raw-visitors))
#'user/browsers

;; and run our computation graph lazily.
user> (defn all-visitors [] 
        (run-graph-strategy 

ithayer

;; Babbage provides some built-in simple accumulators.
user> (use 'babbage.core)
user> (require '[babbage.provided.core :as p])
nil

;; Create several sets of interest.
user> (def mysets 
        (sets  {:firefox? #(-> % :browser (= :firefox))
                :chrome?  #(-> % :browser (= :chrome))
                :ie?      #(-> % :browser #{:ie-7 :ie-8 :ie-9 :ie-10})

ithayer

;; In project.clj
:plugins [[s3-wagon-private "1.1.2"]]
:repositories {"private" {:url "s3p://mybucket/releases/" 
                          :passphrase :env 
                          :username :env}}

;; Gotcha 1: Using :creds :env didn't seem to work for me. 
;; Gotcha 2: Using a location of just s3p://mybucket didn't 
;;   seem to work, the releases/ directory is needed.