Boris Cherny bcherny

The introduction to Reactive Programming you've been missing

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.

Basic unit type:

λ> replTy "()"
() :: ()

Basic functions:

What is the appeal of dynamically-typed languages?

Kris Nuttycombe asks:

I genuinely wish I understood the appeal of unityped languages better. Can someone who really knows both well-typed and unityped explain?

I think the terms well-typed and unityped are a bit of question-begging here (you might as well say good-typed versus bad-typed), so instead I will say statically-typed and dynamically-typed.

I'm going to approach this article using Scala to stand-in for static typing and Python for dynamic typing. I feel like I am credibly proficient both languages: I don't currently write a lot of Python, but I still have affection for the language, and have probably written hundreds of thousands of lines of Python code over the years.

	var webdriver = require('selenium-webdriver');
	var fs = require('fs');

	var driver = new webdriver.Builder().build();

	webdriver.WebDriver.prototype.saveScreenshot = function(filename) {
	return driver.takeScreenshot().then(function(data) {
	fs.writeFile(filename, data.replace(/^data:image\/png;base64,/,''), 'base64', function(err) {
	if(err) throw err;
	});

	# Add the following 'help' target to your Makefile
	# And add help text after each target name starting with '\#\#'

	help: ## Show this help.
	@fgrep -h "##" $(MAKEFILE_LIST) \| fgrep -v fgrep \| sed -e 's/\\$$//' \| sed -e 's/##//'

	# Everything below is an example

	target00: ## This message will show up when typing 'make help'
	@echo does nothing

	source: http://www.markbrilman.nl/2011/08/howto-convert-a-pfx-to-a-seperate-key-crt-file/

	`openssl pkcs12 -in [yourfile.pfx] -nocerts -out [keyfile-encrypted.key]`

	What this command does is extract the private key from the .pfx file. Once entered you need to type in the importpassword of the .pfx file. This is the password that you used to protect your keypair when you created your .pfx file. If you cannot remember it anymore you can just throw your .pfx file away, cause you won’t be able to import it again, anywhere!. Once you entered the import password OpenSSL requests you to type in another password, twice!. This new password will protect your .key file.

	Now let’s extract the certificate:

	`openssl pkcs12 -in [yourfile.pfx] -clcerts -nokeys -out [certificate.crt]`

	#!/bin/bash
	#
	# Bash script to setup headless Selenium (uses Xvfb and Chrome)
	# (Tested on Ubuntu 12.04) trying on ubuntu server 14.04

	# Add Google Chrome's repo to sources.list
	echo "deb http://dl.google.com/linux/chrome/deb/ stable main" \| sudo tee -a /etc/apt/sources.list

	# Install Google's public key used for signing packages (e.g. Chrome)
	# (Source: http://www.google.com/linuxrepositories/)

	define(function(require) {
	var React = require('react');

	var paramRegex = /__(\d)+/;
	var parser = new DOMParser();
	var errorDoc = parser.parseFromString('INVALID', 'text/xml');
	var errorNs = errorDoc.getElementsByTagName("parsererror")[0].namespaceURI;

	// turns the array of string parts into a DOM
	// throws if the result is an invalid XML document.

	var HashTable = function() {
	this._storage = [];
	this._count = 0;
	this._limit = 8;
	}


	HashTable.prototype.insert = function(key, value) {
	//create an index for our storage location by passing it through our hashing function
	var index = this.hashFunc(key, this._limit);