Pawel Ceranka qazwsxpawel

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

Backend Architectures

Twitter

ror, scala, jetty, erlang, thrift, mongrel, comet server, my-sql, memchached, varnish, kestrel(mq), starling, gizzard, cassandra, hadoop, vertica, munin, nagios, awstats

Introduce Gizzard of Twitter - 트위터의 새로운 분산 관리 라이브러리 Gizzard를 소개합니다.
The Architecture Twitter Uses to Deal with 150M Active Users, 300K QPS, a 22 MB/S Firehose, and Send Tweets in Under 5 Seconds
Scaling Twitter: Making Twitter 10000 Percent Faster

This is unmaintained, please visit Ben-PH/spacemacs-cheatsheet

Useful Spacemacs commands

SPC q q - quit
SPC w / - split window vertically
SPC w - - split window horizontally
SPC 1 - switch to window 1
SPC 2 - switch to window 2
SPC w c - delete current window

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

This document has moved!

It's now here, in The Programmer's Compendium. The content is the same as before, but being part of the compendium means that it's actively maintained.

	; A REPL-based, annotated Seesaw tutorial
	; Please visit https://github.com/daveray/seesaw for more info
	;
	; This is a very basic intro to Seesaw, a Clojure UI toolkit. It covers
	; Seesaw's basic features and philosophy, but only scratches the surface
	; of what's available. It only assumes knowledge of Clojure. No Swing or
	; Java experience is needed.
	;
	; This material was first presented in a talk at @CraftsmanGuild in
	; Ann Arbor, MI.

	;; based on core.logic 0.8-alpha2 or core.logic master branch

	(ns sudoku
	(:refer-clojure :exclude [==])
	(:use clojure.core.logic))

	(defn get-square [rows x y]
	(for [x (range x (+ x 3))
	y (range y (+ y 3))]
	(get-in rows [x y])))

	;; Big thanks to Christophe Grand - https://groups.google.com/d/msg/clojure/L1GiqSyQVVg/m-WJogaqU8sJ
	(defn scaffold [iface]
	(doseq [[iface methods] (->> iface .getMethods
	(map #(vector (.getName (.getDeclaringClass %))
	(symbol (.getName %))
	(count (.getParameterTypes %))))
	(group-by first))]
	(println (str " " iface))
	(doseq [[_ name argcount] methods]
	(println

	(require '[clojure.core.async :as a])

	(def xform (comp (map inc)
	(filter even?)
	(dedupe)
	(flatmap range)
	(partition-all 3)
	(partition-by #(< (apply + %) 7))
	(flatmap flatten)
	(random-sample 1.0)

	#!/bin/bash

	# Locate the history file in your profile, and copy it to the same folder as this script.
	# On Mac: ~/Library/Application\ Support/Google/Chrome/Default/History
	# On Windows: C:\Users\YOUR USER NAME\AppData\Local\Google\Chrome\User Data\Default\History

	sqlite3 History <<!
	.headers on
	.mode csv
	.output out.csv