adamz adam-zethraeus

In August 2007 a hacker found a way to expose the PHP source code on facebook.com. He retrieved two files and then emailed them to me, and I wrote about the issue:

http://techcrunch.com/2007/08/11/facebook-source-code-leaked/

It became a big deal:

http://www.techmeme.com/070812/p1#a070812p1

The two files are index.php (the homepage) and search.php (the search page)

A composable pattern for pure state machines with effects

State machines are everywhere in interactive systems, but they're rarely defined clearly and explicitly. Given some big blob of code including implicit state machines, which transitions are possible and under what conditions? What effects take place on what transitions?

There are existing design patterns for state machines, but all the patterns I've seen complect side effects with the structure of the state machine itself. Instances of these patterns are difficult to test without mocking, and they end up with more dependencies. Worse, the classic patterns compose poorly: hierarchical state machines are typically not straightforward extensions. The functional programming world has solutions, but they don't transpose neatly enough to be broadly usable in mainstream languages.

Here I present a composable pattern for pure state machiness with effects,

pretty_csv/pretty_tsv

These are some simple bash functions and scripts for making CSV/TSV files prettier on the command line

see http://stefaanlippens.net/pretty-csv.html for more information.

	#include <stdio.h>
	#include <stdint.h>
	#include <stdlib.h>

	#define XLIM 17
	#define YLIM 9
	#define ARSZ (XLIM * YLIM)

	#define DEBUG 0

	//
	// MultiDirectionAdjudicatingScrollView.swift
	// Khan Academy
	//
	// Created by Andy Matuschak on 12/16/14.
	// Copyright (c) 2014 Khan Academy. All rights reserved.
	//

	import UIKit
	import UIKit.UIGestureRecognizerSubclass

	var active = false;

	function changeRefer(details) {
	if (!active) return;

	for (var i = 0; i < details.requestHeaders.length; ++i) {
	if (details.requestHeaders[i].name === 'Referer') {
	details.requestHeaders[i].value = 'http://www.google.com/';
	break;
	}

	// Adapted from Stack Overflow answer by David Crow http://stackoverflow.com/a/43235
	// Question: Algorithm to randomly generate an aesthetically-pleasing color palette by Brian Gianforcaro
	// Method randomly generates a pastel color, and optionally mixes it with another color
	func generateRandomPastelColor(withMixedColor mixColor: UIColor?) -> UIColor {
	// Randomly generate number in closure
	let randomColorGenerator = { ()-> CGFloat in
	CGFloat(arc4random() % 256 ) / 256
	}

	var red: CGFloat = randomColorGenerator()

	import Foundation

	extension UnicodeScalar : ForwardIndexType {
	public func successor() -> UnicodeScalar {
	return UnicodeScalar(value + 1)
	}
	}

	var operatorHeads: [UnicodeScalar] = Array("=-+!*%<>&\|^~?".unicodeScalars)
	operatorHeads += Array("\u{00A1}" ... "\u{00A7}")

	/// Decodes a dynamically-generated Uniform Type Identifier for inspection purposes. (NOT FOR PRODUCTION USE!)
	/// Many, many thanks to http://alastairs-place.net/blog/2012/06/06/utis-are-better-than-you-think-and-heres-why/
	///
	/// <https://developer.apple.com/library/ios/documentation/FileManagement/Conceptual/understanding_utis/understand_utis_conc/understand_utis_conc.html#//apple_ref/doc/uid/TP40001319-CH202-BCGCDHIJ>
	func decodeDynUTI(_ uti: String) -> String?
	{
	let vec = Array("abcdefghkmnpqrstuvwxyz0123456789")

	let encoded = Array(uti).suffix(from: 5)
	var result: [UInt8] = []