ghoseb

;;
;; NS CHEATSHEET
;;
;; * :require makes functions available with a namespace prefix
;;  and optionally can refer functions to the current ns.
;;
;; * :import refers Java classes to the current namespace.
;;
;; * :refer-clojure affects availability of built-in (clojure.core)
;;   functions.

hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

astoddard

(-> [jay john mike chris]
    (->> (filter (comp (partial = "new york") :current-city)))
    (->> (group-by :employer))
    (update-in ["drw.com"] (partial map :name)))

nblumoe

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

john2x

Clojure Destructuring Tutorial and Cheat Sheet

(Related blog post)

Simply put, destructuring in Clojure is a way extract values from a datastructure and bind them to symbols, without having to explicitly traverse the datstructure. It allows for elegant and concise Clojure code.

Vectors and Sequences

alandipert

alan@alanputer:~/Desktop$ tree
.
└── jars
    └── upcase-2.0.0.jar

1 directory, 1 file
alan@alanputer:~/Desktop$ boot repl
nREPL server started on port 50498 on host 127.0.0.1 - nrepl://127.0.0.1:50498
REPL-y 0.3.5, nREPL 0.2.8
Clojure 1.6.0

ohanhi

Learning FP the hard way: Experiences on the Elm language

by Ossi Hanhinen, @ohanhi

with the support of Futurice 💚.

Licensed under CC BY 4.0.

Editorial note

micha

(defn throttle [c ms]
  (let [queued? (atom false)]
    (with-let [ret (cell @c)]
      (add-watch c (gensym)
        #(when-not @queued?
           (reset! queued? true)
           (with-timeout ms
             (reset! queued? false)
             (reset! ret @c)))))))

micha

(ns ui.form
  (:refer-hoplon :exclude [select input textarea label form])
  (:require [ui.form.input :as input]
            [ui.button     :as button]
            [ui.modal      :as modal]
            [ui.grid       :as grid]
            [ui.filters    :as filters]
            [ui.link       :as link]
            [ui.util       :as util]
            [ui.icon       :as icon]

ttscoff

-- A global variable for the Hyper Mode
k = hs.hotkey.modal.new({}, "F17")

-- Trigger existing hyper key shortcuts

k:bind({}, 'm', nil, function() hs.eventtap.keyStroke({"cmd","alt","shift","ctrl"}, 'm') end)

-- OR build your own

launch = function(appname)