Casey R. White casecode

Moving to ES6 from CoffeeScript

I fell in love with CoffeeScript a couple of years ago. Javascript has always seemed something of an interesting curiosity to me and I was happy to see the meteoric rise of Node.js, but coming from a background of Python I really preferred a cleaner syntax.

In any fast moving community it is inevitable that things will change, and so today we see a big shift toward ES6, the new version of Javascript. It incorporates a handful of the nicer features from CoffeeScript and is usable today through tools like Babel. Here are some of my thoughts and issues on moving away from CoffeeScript in favor of ES6.

While reading I suggest keeping open a tab to Babel's learning ES6 page. The examples there are great.

Punctuation

Holy punctuation, Batman! Say goodbye to your whitespace and hello to parenthesis, curly braces, and semicolons again. Even with the advanced ES6 syntax you'll find yourself writing a lot more punctuatio

	'use strict';

	var co = require('co'),
	fs = require('co-fs'),
	each = require('co-each');


	var dive = function* (path) {

	var items = yield fs.readdir(path);

	{
	// http://eslint.org/docs/rules/

	"ecmaFeatures": {
	"binaryLiterals": false, // enable binary literals
	"blockBindings": false, // enable let and const (aka block bindings)
	"defaultParams": false, // enable default function parameters
	"forOf": false, // enable for-of loops
	"generators": false, // enable generators
	"objectLiteralComputedProperties": false, // enable computed object literal property names

	%li
	-# https://developers.facebook.com/docs/reference/dialogs/feed/#redirect
	%a{:href => "https://www.facebook.com/sharer/sharer.php?u=#{u request.original_url}", :target=>"blank", :rel=>"external nofollow"}
	%span.fa.fa-facebook.fa-2x
	%span.text-hide Facebook
	%li
	-# http://stackoverflow.com/a/11212220/94668
	%a{:href => "//pinterest.com/pin/create/button/?url=#{u request.original_url}", :target=>"blank", :rel=>"external nofollow"}
	%span.fa.fa-pinterest.fa-2x
	%span.text-hide Pinterest

	MyExceptions = [RangeError, RegexpError, IOError].freeze

	begin
	raise IOError, "should be rescued"
	rescue *MyExceptions => e
	puts e
	end

	upstream myapp {
	server unix:///myapp/tmp/puma.sock;
	}

	server {
	listen 80;
	server_name myapp.com;

	# ~2 seconds is often enough for most folks to parse HTML/CSS and
	# retrieve needed images/icons/frames, connections are cheap in

	/* Extends the Class Object Written by Resig. http://ejohn.org/blog/simple-javascript-inheritance/ */
	Class.prototype.addObserver = function(/** String / key, /* Object / observer, /* Function */ method)
	{
	if (key !== null && key !== undefined &&
	observer !== null && observer !== undefined &&
	method !== null && method !== undefined)
	{
	eval("this._" + key + " = this." + key);

	this.__defineGetter__(key, function()

	/*
	* Example how to preload HTML5 video on the iPad (iOS 3.2+)
	* @author Miller Medeiros
	* Released under WTFPL
	*/

	var vid = document.createElement('video');
	vid.src = 'lol_catz.mp4';
	document.getElementById('video-holder').appendChild(vid);

	# NOTICE: to get Nginx+Unicorn best-practices configuration see the gist https://gist.github.com/3052776

	$ cd /usr/src
	$ wget http://nginx.org/download/nginx-1.2.1.tar.gz
	$ tar xzvf ./nginx-1.2.1.tar.gz && rm -f ./nginx-1.2.1.tar.gz

	$ wget ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-8.30.tar.gz
	$ tar xzvf pcre-8.30.tar.gz && rm -f ./pcre-8.30.tar.gz

	$ wget http://www.openssl.org/source/openssl-1.0.1c.tar.gz