andymatuschak

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,

MrAlek

import UIKit

enum Direction {
    case Left, Right, Up, Down
    
    var pointVector: CGPoint {
        switch self {
        case Left: return CGPoint(x: -1, y: 0)
        case Right: return CGPoint(x: 1, y: 0)
        case Up: return CGPoint(x: 0, y: -1)

natecook1000

// NSCalendar+Swift.swift
// A set of Swift-idiomatic methods for NSCalendar
//
// (c) 2015 Nate Cook, licensed under the MIT license

extension NSCalendar {
    /// Returns the hour, minute, second, and nanoseconds of a given date.
    func getTimeFromDate(date: NSDate) -> (hour: Int, minute: Int, second: Int, nanosecond: Int) {
        var (hour, minute, second, nanosecond) = (0, 0, 0, 0)
        getHour(&hour, minute: &minute, second: &second, nanosecond: &nanosecond, fromDate: date)

natecook1000

// (c) 2014 Nate Cook, licensed under the MIT license
//
// Fisher-Yates shuffle as top-level functions and array extension methods

/// Shuffle the elements of `list`.
func shuffle<C: MutableCollectionType where C.Index == Int>(inout list: C) {
    let c = count(list)
    for i in 0..<(c - 1) {
        let j = Int(arc4random_uniform(UInt32(c - i))) + i
        swap(&list[i], &list[j])

quellish

Variable

Type

jaredsinclair

# Set the build number to the current git commit count.
#
# Permanent home:
# https://gist.github.com/jaredsinclair/af6898f93674ee5923f3
#
# Based on: http://w3facility.info/question/how-do-i-force-xcode-to-rebuild-the-info-plist-file-in-my-project-every-time-i-build-the-project/
# Updated with dSYM handling from http://yellowfeather.co.uk/blog/auto-incrementing-build-number-in-xcode-revisited/

git=`sh /etc/profile; which git`
appBuild=`"$git" rev-list HEAD --count`

mattt

Generate the list yourself:

$ cd /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS*.sdk/System/Library/Frameworks/UIKit.framework/Headers
$ grep UI_APPEARANCE_SELECTOR ./*     | \
  sed 's/NS_AVAILABLE_IOS(.*)//g'     | \
  sed 's/NS_DEPRECATED_IOS(.*)//g'    | \
  sed 's/API_AVAILABLE(.*)//g'        | \
  sed 's/API_UNAVAILABLE(.*)//g'      | \
 sed 's/UI_APPEARANCE_SELECTOR//g' | \

brobertsaz

Ubuntu 12.04, Ruby, Rails, Nginx, Unicorn and git-deploy

In the seemlingly endless search for the actual correct and easy way to deploy a Rails app, we have tried several ways. We tried out using Apache2 and running a cluster of Thin servers. With the built in threading of Puma we decided to use it with Nginx.

Server Setup

• Create new server
• Login to new server
  • ssh root@IPaddress (you can also use the domain name if you have the DNS setup already)
  • accept the RSA key

axelpale

/**
 * Copyright 2012 Akseli Palén.
 * Created 2012-07-15.
 * Licensed under the MIT license.
 * 
 * <license>
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,