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Setting Up Clojure on OS X

I spent a lot of time trying to find a pretty optimal (for me) setup for Clojure… at the same time I was trying to dive in and learn it. This is never optimal; you shouldn't be fighting the environment while trying to learn something.

I feel like I went through a lot of pain searching Google, StackOverflow, blogs, and other sites for random tidbits of information and instructions.

This is a comprehensive "what I learned and what I ended up doing" that will hopefully be of use to others and act as a journal for myself if I ever have to do it again. I want to be very step-by-step and explain what's happening (and why) at each step.

Step 1: Getting Clojure (1.3)

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

	# Apt-install various things necessary for Ruby, guest additions,
	# etc., and remove optional things to trim down the machine.
	apt-get -y update
	apt-get -y remove apparmor
	apt-get -y install linux-headers-$(uname -r) build-essential
	apt-get -y install zlib1g zlib1g-dev libxml2 libxml2-dev libxslt-dev libssl-dev openssl libreadline5-dev
	apt-get clean

	# Remove this file to avoid dhclient issues with networking
	rm -f /etc/udev/rules.d/70-persistent-net.rules

	# Simple bijective function
	# Basically encodes any integer into a base(n) string,
	# where n is ALPHABET.length.
	# Based on pseudocode from http://stackoverflow.com/questions/742013/how-to-code-a-url-shortener/742047#742047

	ALPHABET =
	"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".split(//)
	# make your own alphabet using:
	# (('a'..'z').to_a + ('A'..'Z').to_a + (0..9).to_a).shuffle.join

	# First install tmux
	brew install tmux

	# For mouse support (for switching panes and windows)
	# Only needed if you are using Terminal.app (iTerm has mouse support)
	Install http://www.culater.net/software/SIMBL/SIMBL.php
	Then install https://bitheap.org/mouseterm/

	# More on mouse support http://floriancrouzat.net/2010/07/run-tmux-with-mouse-support-in-mac-os-x-terminal-app/

	#########################################
	# Very basic rack application showing how to use a router based on the uri
	# and how to process requests based on the HTTP method used.
	#
	# Usage:
	# $ rackup rack_example.ru
	#
	# $ curl -X POST -d 'title=retire&body=I should retire in a nice island' localhost:9292/ideas
	# $ curl -X POST -d 'title=ask Satish for a gift&body=Find a way to get Satish to send me a gift' localhost:9292/ideas
	# $ curl localhost:9292/ideas

	function validate_rid(id) {
	// 18位身份证号
	// 国家标准《GB 11643-1999》
	function rid18(id) {
	if(! /\d{17}[\dxX]/.test(id)) {
	return false;
	}
	var modcmpl = function(m, i, n) { return (i + n - m % i) % i; },
	f = function(v, i) { return v * (Math.pow(2, i-1) % 11); },
	s = 0;

	#Model

	@user.should have(1).error_on(:username) # Checks whether there is an error in username
	@user.errors[:username].should include("can't be blank") # check for the error message

	#Rendering
	response.should render_template(:index)

	#Redirecting
	response.should redirect_to(movies_path)

	# -- encoding: utf-8 --
	require 'digest/md5'
	require 'nestful'

	class Smsbao

	def initialize(login, passwd)
	@login = login
	@passwd = Digest::MD5.hexdigest(passwd.to_s)
	end

	/*
	A Tour of Go: page 44
	http://tour.golang.org/#44

	Exercise: Loops and Functions

	As a simple way to play with functions and loops, implement the square root function using Newton's method.

	In this case, Newton's method is to approximate Sqrt(x) by picking a starting point z and then repeating: z - (zz - x) / (2 z)