tiensonqin

cd ~
sudo apt-get update
sudo apt-get install openjdk-7-jre-headless -y

wget https://github.com/elasticsearch/elasticsearch/archive/v0.20.1.tar.gz -O elasticsearch.tar.gz
tar -xf elasticsearch.tar.gz
rm elasticsearch.tar.gz
sudo mv elasticsearch-* elasticsearch
sudo mv elasticsearch /usr/local/share

tiensonqin

;; named arguments from the joy of clojure
;; the clojure version just feels not elegant, why?

;; clojure version
(defn slope
  [& {:keys [p1 p2] :or {p1 [0 0] p2 {1 1}}}]
  (float (/ (- (p2 1) (p1 1))
            (- (p2 0) (p1 0)))))

(slope :p1 [4 15] :p2 [3 21])

tiensonqin

(defstruct item :title :current-price)
(defstruct bid :user :amount)
(def ^:dynamic history ())
(def ^:dynamic droid (struct item "Droid X" 0))
(defn place-offer [offer]
  (binding [history (cons offer history)
            droid (assoc droid :current-price (get offer :amount))]
    (println droid history)))
(place-offer {:user "Anthony" :amount 10})
(println droid)

tiensonqin

(def d (delay (println "Running>>>")
         :done!))

(deref d)

(defn get-document
  [id]
  {:content (delay (slurp "http://www.baidu.com"))})

(get-document "some-id")

tiensonqin

(defmacro futures
  [n & exprs]
  (vec (for [_ (range n)
             expr exprs]
         `(future ~expr))))

(defmacro wait-futures
  [& args]
  `(doseq [f# (futures ~@args)]
     @f#))

tiensonqin

;; Lists

(def l (list))
(cons 1 l)
(conj (conj l 1) 1)
(rest (conj l 1))
(pop l)

;; vectors
(def v [1 2 3])

tiensonqin

SET @center = GeomFromText('POINT(34 110)');
SET @radius = 30;
SET @bbox = CONCAT('POLYGON((',
X(@center) - @radius, ' ', Y(@center) - @radius, ',',
X(@center) + @radius, ' ', Y(@center) - @radius, ',',
X(@center) + @radius, ' ', Y(@center) + @radius, ',',
X(@center) - @radius, ' ', Y(@center) + @radius, ',',
X(@center) - @radius, ' ', Y(@center) - @radius, '))'
);
SELECT AsText(point)

tiensonqin

(defn memoize [f]
  (let [mem (atom {})]
    (fn [& args]
      (if-let [e (find @mem args)]
        (val e)
        (let [ret (apply f args)]
          (swap! mem assoc args ret)
          (prn @mem)
          ret)))))

tiensonqin

user> (+ 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M )
0.9M
user> (+ 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M )
1.0M
user> (+ 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1)
1.0
user> (+ 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1)
0.9
user> (+ 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1M 0.1 0.1M)
1.0

tiensonqin

102 
103 server {
104   listen 80;
105   server_name bookmarking.curtis.io;
106 
107   location / {
108     expires 24h;
109     proxy_pass http://localhost:3000/;
110     sendfile on;
111     proxy_redirect off;