Kashyap kgrz

Finding a Ruby memory leak using a time analysis

When developing a program in Ruby, you may sometimes encounter a memory leak. For a while now, Ruby has a facility to gather information about what objects are laying around: ObjectSpace.

There are several approaches one can take to debug a leak. This discusses a time-based approach, where a full memory dump is generated every, say, 5 minutes, during a time that the memory leak is showing up. Afterwards, one can look at all the objects, and find out which ones are staying around, causing the

Learning

ES6 Katas - Small, byte-size exercises to discover most aspects of ES6 features by doing interactive, online exercises. Pretty awesome.
Learn ES2015 - A great part of Babel's website that takes you through examples of all supported ES6+ features
ES6-Features.org - Nice ES6 / ES5 comparisons of many ES6 language features
ES6 Features - A single-page tour of code examples for just about every ES6 feature, by Luke Hoban

Exploring in-depth

ES6 In Depth - A great series of articles on Mozilla Developer Network (MDN); also available in French through great translation efforts.

#!/usr/bin/env bash

# Assuming OS X Yosemite 10.10.4

# Install XCode and command line tools
# See https://itunes.apple.com/us/app/xcode/id497799835?mt=12#
# See https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man1/xcode-select.1.html
xcode-select --install

A small clone of Sinatra

For the purpose of learning.

Run the example app

TLDR: a React component should either manage its own state, or expose a callback so that its parent can. But never both.

Sometimes our first impulse is for a component to entirely manage its own state. Consider this simple theater seating picker that has a letter for a row, and a number for a seat. Clicking the buttons to increment each value is hardly the height of user-interface design, but never mind - that's how it works:

/* @flow */
var React = require('react');

var Letter: React.ReactClass = React.createClass({
  getInitialState: function(): any {

I highly suspect that the RSpec core team all use black backgrounds in their terminals because sometimes the colors aren’t so nice on my white terminal

I certainly use a black background. I'm not sure about the other RSpec core folks. Regardless, if there are some color changes we can make that would make output look good on a larger variety of backgrounds, we'll certainly consider that (do you have some suggested changes?). In the meantime, the colors are configurable, so you can change the colors to fit your preferences on your machine. First, create a file at

	/* bling.js */
	window.$ = document.querySelector.bind(document);
	window.$$ = document.querySelectorAll.bind(document);
	Node.prototype.on = window.on = function(name, fn) { this.addEventListener(name, fn); };
	NodeList.prototype.__proto__ = Array.prototype;
	NodeList.prototype.on = function(name, fn) { this.forEach((elem) => elem.on(name, fn)); };

	* {}

	tag {}

	[attribute] {}

	[attribute="value"] {}

	.class {}

	import java.io.FileDescriptor;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.io.OutputStream;
	import java.io.PrintStream;

	public class HelloWorld{
	private static HelloWorld instance;
	public static void main(String[] args){
	instantiateHelloWorldMainClassAndRun();

	import { Component } from "React";

	export var Enhance = ComposedComponent => class extends Component {
	constructor() {
	this.state = { data: null };
	}
	componentDidMount() {
	this.setState({ data: 'Hello' });
	}
	render() {