yw yang-wei

Compiling your ES6 command line apps to work with node.js

This post has moved to my personal blog: http://maximilianschmitt.me/posts/compile-es6-command-line-apps/

Learning FP the hard way: Experiences on the Elm language

by Ossi Hanhinen, @ohanhi

with the support of Futurice 💚.

Licensed under CC BY 4.0.

Editorial note

Using Mailboxes in Elm

Max Goldstein | July 30, 2015 | Elm 0.15.1

In Elm, signals always have a data source associated with them. Window.dimensions is exactly what you think it is, and you can't send your own events on it. You can derive your own signals from these primitives using map, filter, and merge, but the timing of events is beyond your control.

This becomes a problem when you try to add UI elements. We want to be able to add checkboxes and dropdown menus, and to receive the current state of these elements as a signal. So how do we do that?

The Bad Old Days

@kangax's ES6 quiz, explained

@kangax created a new interesting quiz, this time devoted to ES6 (aka ES2015). I found this quiz very interesting and quite hard (made myself 3 mistakes on first pass).

Here we go with the explanations:

Question 1:

(function(x, f = () =&gt; x) {

Should be work with 0.18

Destructuring(or pattern matching) is a way used to extract data from a data structure(tuple, list, record) that mirros the construction. Compare to other languages, Elm support much less destructuring but let's see what it got !

Tuple

myTuple = ("A", "B", "C")
myNestedTuple = ("A", "B", "C", ("X", "Y", "Z"))

When receiving JSON data from other resources(server API etc), we need Json.Decode to convert the JSON values into Elm values. This gist let you quickly learn how to do that.

I like to follow working example code so this is how the boilerplate will look like:

import Graphics.Element exposing (Element, show)
import Task exposing (Task, andThen)
import Json.Decode exposing (Decoder, int, string, object3, (:=))

import Http

How to setup AWS lambda function to talk to the internet and VPC

I'm going to walk you through the steps for setting up a AWS Lambda to talk to the internet and a VPC. Let's dive in.

So it might be really unintuitive at first but lambda functions have three states.

No VPC, where it can talk openly to the web, but can't talk to any of your AWS services.
VPC, the default setting where the lambda function can talk to your AWS services but can't talk to the web.
VPC with NAT, The best of both worlds, AWS services and web.

Stuff I wish I'd known sooner about service workers

I recently had several days of extremely frustrating experiences with service workers. Here are a few things I've since learned which would have made my life much easier but which isn't particularly obvious from most of the blog posts and videos I've seen.

I'll add to this list over time – suggested additions welcome in the comments or via twitter.com/rich_harris.

Use Canary for development instead of Chrome stable

~~Chrome 51 has some pretty wild behaviour related to console.log in service workers. Canary doesn't, and it has a load of really good service worker related stuff in devtools.~~

	/**
	* Basic proof of concept.
	* - Hot reloadable
	* - Stateless stores
	* - Stores and action creators interoperable with Redux.
	*/

	import React, { Component } from 'react';

	export default function dispatch(store, atom, action) {

	var root = this;
	// embed: dataset, util, browser, mobilephone, crawler, appliance, misc, woothee

	// GENERATED from dataset.yaml at Thu Aug 13 14:22:28 JST 2015 by tagomoris

	// Snapshot from package.json
	var package_info = {"name":"woothee","version":"1.2.0","description":"User-Agent string parser (js implementation)","main":"./release/woothee","devDependencies":{"mocha":">= 1.7.0","chai":">= 1.3.0","js-yaml":">= 1.0.3","should":"~1.2.2"},"scripts":{"test":"make test"},"repository":{"type":"git","url":"https://github.com/woothee/woothee-js"},"author":"tagomoris","license":"Apache v2"};

	var dataset = {};
	(function(){