Timo Tijhof Krinkle

Non-deterministic module ordering is an even bigger footgun

Update – in the comments below, @bmeck clarifies that statically imported modules do evaluate in a deterministic sequential order, contra the Hacker News comments that prompted this gist.

Another follow-up to Top-level await is a footgun. On the Hacker News comments, Domenic says this:

(The argument also seems to be predicated on some fundamental misunderstandings, in that it thinks everything would have to be sequentialized. See my other replies throughout this thread.)

In other words, if you have an app like this...

Edit — February 2019

This gist had a far larger impact than I imagined it would, and apparently people are still finding it, so a quick update:

TC39 is currently moving forward with a slightly different version of TLA, referred to as 'variant B', in which a module with TLA doesn't block sibling execution. This vastly reduces the danger of parallelizable work happening in serial and thereby delaying startup, which was the concern that motivated me to write this gist
In the wild, we're seeing (async main(){...}()) as a substitute for TLA. This completely eliminates the blocking problem (yay!) but it's less powerful, and harder to statically analyse (boo). In other words the lack of TLA is causing real problems
Therefore, a version of TLA that solves the original issue is a valuable addition to the language, and I'm in full support of the current proposal, which you can read here.

I'll leave the rest of this document unedited, for archaeological

Apps to install from macOS App Store:

Pastebot
GIF Brewery
Slack
Keynote/Pages/Numbers
1Password
OmniFocus 3
Airmail 3
iA Writer

	/**
	* Encrypts plaintext using AES-GCM with supplied password, for decryption with aesGcmDecrypt().
	* (c) Chris Veness MIT Licence
	*
	* @param {String} plaintext - Plaintext to be encrypted.
	* @param {String} password - Password to use to encrypt plaintext.
	* @returns {String} Encrypted ciphertext.
	*
	* @example
	* const ciphertext = await aesGcmEncrypt('my secret text', 'pw');

	CoreTeam: &CoreTeam
	Characters:
	- Mario
	- Luigi

	ExtendedTeam: &ExtendedTeam
	<<: *CoreTeam
	Characters+:
	- Princess Peach
	- Yoshi

	// This is my solution to the "Little JavaScript Problem" from http://lisperator.net/blog/a-little-javascript-problem/
	// Apparently this means Mihai Bazon will hire me... Woo!

	var pair = (head, tail) => (f => f(head, tail))
	var car = (pair) => pair((head, tail) => head)
	var cdr = (pair) => pair((head, tail) => tail)
	var range = (min, max) => pair(min, min == max ? null : range(min + 1, max))
	var map = (list, func) => pair(func(car(list)), cdr(list) === null ? null : map(cdr(list), func))
	var reverse = (list, newList=null) => list === null ? newList : reverse(cdr(list),pair(car(list), newList))
	var foreach = (list, func) => list === null ? null : (func(car(list)), foreach(cdr(list), func))

	function monitorEvents(element) {
	var log = function(e) { console.log(e);};
	var events = [];

	for(var i in element) {
	if(i.startsWith("on")) events.push(i.substr(2));
	}
	events.forEach(function(eventName) {
	element.addEventListener(eventName, log);
	});

	#!/usr/bin/env bash
	file_pattern='*.js' # Which files to consider
	v1="php-1.28.0-wmf.18" # Base branch
	v2="php-1.28.0-wmf.17" # Target branch
	while IFS= read -r a; do
	b="${a/$v1/$v2}"
	diff -u "$a" "$b" # Change '-u' to '-q' if you only want
	# to list which files have changed.
	done < <(find "/srv/mediawiki/${v1}" -name "$file_pattern")

	var supportsES6 = function() {
	try {
	new Function("(a = 0) => a");
	return true;
	}
	catch (err) {
	return false;
	}
	}();

	#!/usr/bin/env python3
	# -- coding: utf8 --
	"""
	takeover.py
	~~~~~~~~~~~
	This script demonstrates a technique for zero-downtime restarts via
	interprocess descriptor transfer.

	The script operates a simple echo service on port 9999. When a new instance
	is launched, the old instance will transfer the server socket to the new