kindlychung

(defn mapify
  "Return a seq of maps like {:name \"Edward Cullen\" :glitter-index 10}"
  [rows]
  (let [;; headers becomes the seq (:name :glitter-index)
        headers (map #(get headers->keywords %) (first rows))
        ;; unmapped-rows becomes the seq
        ;; (["Edward Cullen" "10"] ["Bella Swan" "0"] ...)
        unmapped-rows (rest rows)]
    ;; Now let's return a seq of {:name "X" :glitter-index 10}
    (map (fn [unmapped-row]

kindlychung

;; Given a vector of headers and a row, make a key-val pair for each column
(defn pair-cols
  [headers columns]
  (into {}
        (map
          (fn [header column] [header ((get conversions header) column)])
          headers columns
          ))
  )
(defn mapify

kindlychung

(defn comp1
  ([]
    ;; No functions provided, return identity
    identity
    )
  ([f]
    ;; A single function provided, return itself
    f
    )
  ([& fs g]

kindlychung

(defn tri*
  "Generates lazy sequence of triangular numbers"
  ([] (tri* 0 1))
  ([sum n]
    (let [new-sum (+ sum n)]
      (cons new-sum (lazy-seq (tri* new-sum (inc n))))
      ))
  )
(defn tri1*
  "Generates lazy sequence of triangular numbers"

kindlychung

(defn testcond 
      [a]
      (
        cond 
        (a > 10) "Greater than 10"
        (a > 100) "Greater than 100"
        else: "Very big!"
        )
      )

kindlychung

;; future runs on another thread, so it's asynchronous
;; in this case it returns
;(future (#(deliver result %&)
;          (+ 8 7)
;          (- 8 7)))
(defn call-service
  [arg1 arg2 callback-fn]
  (future (callback-fn (+ arg1 arg2)
                       (- arg1 arg2)))
  )

kindlychung

(defn echo-watch
  [key identity old new]
  (println key old "=>" new))
(def sarah (atom {:name "Sarah" :age 25}))
(add-watch sarah :echo echo-watch)
(swap! sarah update-in [:age] inc)

kindlychung

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Some code from Clojure Programming book [Chas Emerick et al.]
(def d
  (delay (println "Running...") :done!)
  )
(deref d)
@d

(defn get-document
  [id]

kindlychung

;; compound interest with the -> macro
(defn final-amount-> [principle rate time-periods]
  (-> rate 
      (/ 100)
      (+ 1)
      (Math/pow time-periods)
      (* principle)))
(final-amount-> 100 20 1)

kindlychung

(use 'criterium.core)
(def f1 (fn [x] (str "hello, " x)))
(def f2 (partial str "hello, "))
(def f3 (fn [& args] (apply str "hello, " args)))
(f1 1)
(f2 1)
(f3 1)
(bench (f1 "victor"))
(bench (f2 "victor"))
(bench (f3 "victor"))