Kevin Gibbons bakkot

Optionally async functions

Or: two-color functions.

The problem: async is infectious.

There's a famous essay about this, called What Color is your Function, which I recommend reading.

For example, say you're writing a bundler. It needs to fetch resources, but is agnostic to how those resources are fetched, so it takes a readResource function from its caller. In some contexts the caller might have those resources synchronously available; in others not. That is, caller might have a synchronous readResource which returns a resource immediately, or an async readResources which returns a promise for a resource, which will need to be unwrapped with await.

`globalThis`

PRO: almost shipping in Chrome, maybe used elsewhere
PRO: is actually correct
CON: might confuse JS beginners

`Global`

PRO: maybe less likely to confuse beginners
PRO/CON: looks like a namespace
CON: requires even more churn on this proposal

d28ebe6d Normative: Specify Date.UTC when called with fewer than two arguments (#642)
0916d813 Normative: Use explicit comparison to compare two lists in Valid Chosen Reads
90ed6ce2 Normative: Call NumberToRawBytes instead of the conversion operation to get the byte values list in Atomics.compareExchange
7949fae4 Normative: Only check for undefined count parameter in Atomics.wake, because it's not marked as optional
a4d0e490 Normative: Unconditionally call ToNumber on the timeout parameter in Atomics.wait, because it's not marked as optional

Keybase proof

I hereby claim:

I am bakkot on github.
I am bakkot (https://keybase.io/bakkot) on keybase.
I have a public key whose fingerprint is FD44 B8F2 65AC E177 48C5 23C8 A07A 119B 504C 8D8F

To claim this, I am signing this object:

	'use strict';
	// see https://github.com/C2SP/C2SP/blob/94012bb895565ab4259263d241a9549c4174ccb0/chacha8rand/chacha8rand.go
	// TODO compare against https://github.com/golang/go/blob/9177e12ccc2115e44de824ae7247ace88617c29a/src/internal/chacha8rand/chacha8_generic.go
	// should be the same but it's a bit hard to compare
	// this is not optimized

	function uint32(n) {
	return n >>> 0;
	}

	import fs from 'fs';
	import { inspect } from 'util';
	import path from 'path';
	import { fileURLToPath } from 'url';

	let __dirname = path.dirname(fileURLToPath(import.meta.url));

	let usersToUpgrade = ['@justingrant:matrix.org'];
	let targetPowerLevel = 50;
	let roomId = '!nSLHQtIRJQxUJbEuGt:matrix.org'; // editor channel; this ID can be obtained from room settings -> Advanced

	'use strict';

	let { parseArgs } = require('util');

	let mainOptions = { help: { type: 'boolean', short: 'h' } };
	let subCommands = {
	__proto__: null,
	foo: fooCommand,
	bar: barCommand,
	};

	let frame = document.body.appendChild(document.createElement('iframe'));
	frame.addEventListener('load', ()=>{
	let w = frame.contentWindow;

	let evt;
	w.addEventListener('error', e=>{evt = e;});

	let scr = w.document.createElement('script');
	scr.text = 'throw 42;';

	var p = () => console.log(f);
	{
	p(); // undefined
	console.log(f); // function f(){}

	f = 1;

	p(); // undefined
	console.log(f); // 1