Andy Friesen andyfriesen

$$ \tag*{r = f(x)} \cfrac {\Gamma \vdash f: (A) \rightarrow B, x: T, r: R} {(A) \rightarrow B <: (T) \rightarrow R} $$

Say we want to spin off threads every so often, but we also need the ability to wait until they all go away before exiting the application.

In Haskell, we can do this naive thing:

main = do
    count <- newTVarIO 0
    
 let spawnThread action = do

	<html>
	<canvas id="canvas" width="256" height="256" />
	<script>
	const canvas = document.getElementById('canvas');
	const ctx = canvas.getContext('2d');
	ctx.fillStyle = 'black';
	ctx.fillRect(0, 0, 256, 256);

	ctx.fillStyle = 'white';


	module Clock = {
	include ReactRe.Component.Stateful;
	let name = "Clock";
	type props = ();
	type state = {now: Js_date.t, timerID: option Js_global.intervalId};

	let getInitialState () => {
	{ now: Js_date.make (), timerID: None };
	};

	// This object will hold all exports.
	var Haste = {};

	/* Thunk
	Creates a thunk representing the given closure.
	If the non-updatable flag is undefined, the thunk is updatable.
	*/
	function T(f, nu) {
	this.f = f;
	if(nu === undefined) {