Vitaly Makarevich vitalymak

Hidden classes in JavaScript and Inline Caching

Knowing how internals work is always a good. Pretty much for everything. Cars, trains, computers, you name it. It gives you an insight on what happens under the hood. You also act/react differently based on this knowledge.

As you might have guessed, it’s also true for web development. Knowledge of CSS transitions allows you to achieve better performance and not to use JavaScript in most cases. Knowledge of V8 internals allows you to write more performant JavaScript code. So let’s talk about V8 a little.

A little about V8

V8 is a JavaScript engine built by Google. Firefox built SpiderMonkey, Opera built Carakan and Microsoft built Chakra. One very important difference between V8 and other JavaScript engines is that V8 doesn’t generate any intermediate code. It compiles JavaScr

adb tcpip 5555 && adb connect 192.168.1.123

http://stackoverflow.com/questions/14357705/adb-over-wireless

With USB cable connected, port 5555 opened across all involved firewalls and debug mode enabled

adb tcpip 5555

sublime /Applications/VirtualBox.app/Contents/Resources/VirtualBoxVM.app/Contents/Info.plist

Insert between LSCanProvideIMVideoDataSource and NSHighResolutionCapable:

<key>LSUIElement</key> <string>1</string>

Source: https://forums.virtualbox.org/viewtopic.php?f=8&t=21676#p305585

	'use strict';

	const ITERATIONS = 10000000;
	const ERROR = new Error('Test error');

	function tryCatcher(fn, ctx, args) {
	try {
	return fn.apply(ctx, args);
	}
	catch(err) {

	brew update
	brew install colordiff

	# modify ~/.bash_profile
	function diff {
	colordiff -u "$@"
	}

	# sample usage:
	# diff file1 file2

	#!/usr/bin/env bash

	. ~/.nvm/nvm.sh

	nvm install 4.6.2 >/dev/null 2>&1
	nvm install 6.9.1 >/dev/null 2>&1

	echo 'console.log("Forked child: " + process.version)' > to-fork.js

	# prints v6.9.1

	# 1) first install coreutils
	brew install coreutils

	# 2) but!!! let them do not replace internal macOS utils by modifying PATH check your ~/.bash_profile
	# that you include brew sbin & coreutils AFTER internal /usr/bin etc.
	export PATH=$PATH:/usr/local/sbin # but NOT!!!: export PATH=/usr/local/sbin:$PATH
	export PATH=$PATH:/usr/local/opt/coreutils/libexec/gnubin

	# 3) add it to your ~/.bash_profile
	function dir_sizes {

	errors = [];

	var promises = [
	Promise.reject(new Error('Rejects immediately!')),
	new Promise((resolve) => setTimeout(resolve, 5000)).then(() => 'Resolved after 5 seconds!')
	];

	promises = promises.map((promise, i) => promise.catch(error => {
	errors[i] = error;
	}));

	git branch -m old_branch new_branch # Rename branch locally
	git push origin :old_branch # Delete the old branch
	git push --set-upstream origin new_branch # Push the new branch, set local branch to track the new remote