pjullah

; Clojure strings are Javascript strings
(def s "This is a string")

; Can access Javascript functions, using dot-prefixed notation
(.toUpperCase s)

; To retrieve an object property
(.-length s)

; Javascript supports method-chaining. To accomplish the same in Clojurescript we would nest the function calls, or better still

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(boot.core/merge-env! :dependencies '[[org.clojure/java.jdbc "x.y.z"][mysql/mysql-connector-java "x.y.z"]])

(require '[clojure.java.jdbc :as sql])

(def db-host "127.0.0.1")      
(def db-port 3306)             
(def db-name "cmdb")           
(def db-user "root")           
(def db-password "my-secret-pw")

pjullah

ctrl-b

d - detach

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(defn one
  [handler]
  (println "handler one")
  (fn [request]
    (println "request one")
    (handler request)))

(defn two
  [handler]
  (println "handler two")

pjullah

shift P # paste before cursor position
v # select range of text

# comment a visual selection
ctrl-v
select lines
shift-i
type character
esc - wait a second

pjullah

;; Lots of Clojure - http://matthiasnehlsen.com/

; best explanation of apply vs map - http://stackoverflow.com/questions/2311528/clojure-apply-vs-map
(apply F [1 2 3 4 5])
;translates to
(F 1 2 3 4 5)

(map F [1 2 3 4 5])
;translates to 
[(F 1) (F 2) (F 3) (F 4) (F 5)]

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; construct a map, using the keys from one vector, and the values from another

(zipmap keys vals)

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for i in {1..999}; do printf '%s\n' "row ${i}" "2011-03-11" ${i} true | paste -sd "," - ; done > data.csv

pjullah

fireplace

• cpr => (require ... :reload)
• cpR => (require ... :reload-all)

Evaluation

• :Eval (clojure code) => runs (clojure code) in repl
• cpp => evaluate inn-most expessions under cursor
• cp<movement> => evaluate text described by <movement>
• cqp => opens quasi-repl
• cqc => quasi-repl command line window

pjullah

(ns the-little-schema.core)

;;; Chapter 3 - Cons the magnificent

;; 1. Always ask null? as the first question in expressing any function
;; 2. Use cons to build lists
;; 3. When building a list, describe the first typical
;;    element, and then cons in onto the natural recursion