Tyler Wardhaugh tylerw

Reader Macros in Common Lisp

This post also appears on lisper.in.

Reader macros are perhaps not as famous as ordinary macros. While macros are a great way to create your own DSL, reader macros provide even greater flexibility by allowing you to create entirely new syntax on top of Lisp.

Paul Graham explains them very well in [On Lisp][] (Chapter 17, Read-Macros):

The three big moments in a Lisp expression's life are read-time, compile-time, and runtime. Functions are in control at runtime. Macros give us a chance to perform transformations on programs at compile-time. ...read-macros... do their work at read-time.

THIS GIST WAS MOVED TO TERMSTANDARD/COLORS REPOSITORY.

PLEASE ASK YOUR QUESTIONS OR ADD ANY SUGGESTIONS AS A REPOSITORY ISSUES OR PULL REQUESTS INSTEAD!

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

Awesome PHP

Awesome PHP has been relocated permanently to its own Github repository. No further updates will made to this gist.

Please open an issue for any new suggestions.

	(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)

	# Complete words from tmux pane(s) {{{1
	# Source: http://blog.plenz.com/2012-01/zsh-complete-words-from-tmux-pane.html
	# Gist: https://gist.github.com/blueyed/6856354
	_tmux_pane_words() {
	local expl
	local -a w
	if [[ -z "$TMUX_PANE" ]]; then
	_message "not running inside tmux!"
	return 1
	fi

	;; Example implementation of Norvig's Spellchecker in Clojure,
	;; using core.async
	;;
	;; There are probably some bugs in this.
	;;
	;; Original problem: https://github.com/ericnormand/spelling-jam
	;; from Lambda Jam, Chicago, 2013: http://lambdajam.com/
	;;
	;; Clojure core.async introduction:
	;; http://clojure.com/blog/2013/06/28/clojure-core-async-channels.html

	#!/usr/bin/env sh

	##
	# This is script with usefull tips taken from:
	# https://github.com/mathiasbynens/dotfiles/blob/master/.osx
	#
	# install it:
	# curl -sL https://raw.github.com/gist/2108403/hack.sh \| sh
	#

	These two files should help you to import passwords from mac OS X keychains to 1password.

	Assumptions:
	1) You have some experience with scripting/are a power-user. These scripts worked for me
	but they haven't been extensively tested and if they don't work, you're on your own!
	Please read this whole document before starting this process. If any of it seems
	incomprehensible/frightening/over your head please do not use these scripts. You will
	probably do something Very Bad and I wouldn't want that.
	2) You have ruby 1.9.2 installed on your machine. This comes as standard with Lion, previous
	versions of OS X may have earlier versions of ruby, which may work, but then again, they

	(ns tetris
	(:import
	(javax.swing JFrame)
	(java.awt Canvas Graphics Color Toolkit)
	(java.awt.event ActionListener KeyListener KeyEvent))
	(:gen-class))

	(def cols 10)
	(def rows 20)
	(def width 300)