Vinh Bachsy vinh0604

macOS Internals

Understand your Mac and iPhone more deeply by tracing the evolution of Mac OS X from prelease to Swift. John Siracusa delivers the details.

Starting Points

How to use this gist

You've got two main options:

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

Linux fun-o-matic

How to have some fun using the terminal.

Install cowsay [0] via : sudo apt-get install cowsay
Install fortune [1] via : sudo apt-get install fortune
Make sure you have Ruby installed via : ruby -v
Install the lolcat [2] via : gem gem install lolcat
Profit!

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             
Syscall on Intel 5150 ...................... 105 ns
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Context switch on Intel 5150 ............. 4,300 ns  =   4 µs

Send 2K bytes over 1 Gbps network ....... 20,000 ns = 20 µs

	package main

	import (
	"fmt"
	"log"

	"golang.org/x/sys/unix"
	)

	// https://www.gnu.org/software/libc/manual/html_node/Sockets.html#Sockets

	class GroupersController < ApplicationController::Base
	def create
	@grouper = Grouper.new(leader: current_member)

	if @grouper.save
	ConfirmedGrouperEmails.new(@grouper).deliver
	AssignBarForGrouper.enqueue(@grouper.id)

	redirect_to home_path
	else

	class GroupersController < ApplicationController::Base
	def create
	@grouper = Grouper.new(leader: current_member)

	if @grouper.save
	confirm_grouper_via_emails(@grouper)
	enqueue_bar_assignment(@grouper)

	redirect_to home_path
	else

	// Load Ember into the global scope by requiring it
	require('ember');

	// Go have fun
	var app = Ember.Application.create();

	// A basic example of how Ruby's constantize _could_ work in JS
	// See https://apidock.com/rails/String/constantize
	function constantize (str) {
	if (typeof str !== 'string') {
	throw new TypeError('must pass in type of string');
	}

	if (str.match(/\W\|\d/)) {
	throw new SyntaxError('must pass in a valid Javascript name');
	}