Public
Edited
May 23, 2023
text = "foo **bar** baz"
worker`
const lezerMarkdown = importScripts("https://esm.sh/@lezer/markdown");
const tree = lezerMarkdown.parser.parse("${text}")
console.log(tree)
`
worker = function(f, e, preamble, transferList) {
const b = new Blob([workertext(f, preamble)], { type: "text/javascript" });
return function(notify) {
const url = URL.createObjectURL(b);
const worker = new Worker(url, {type: 'module'});
worker.addEventListener("message", r => notify(r.data));
worker.postMessage(e, transferList);
return () => {
worker.terminate();
URL.revokeObjectURL(url);
};
};
}
webWorker = (method) =>
function (f, ...vars) {
let t = f[0];
const args = {};
for (let i = 0; i < vars.length; i++)
t = `${t}${
typeof vars[i] === "function"
? function_stringify(vars[i])
: ((args[`a${i}`] = vars[i]), `data.a${i}`)
}${f[i + 1]}`;
return Generators[method](
worker(
{
toString: () => `function main(data) {\n${t}\n;;;\n}`,
name: "main"
},
args
)
);
}
observeWorker = webWorker("observe")
// just like Observable, we don't want to iterate on arrays
// so we check if our iterator has a method .next()
function workertext(f, preamble = "") {
return `
${preamble}
function isIterable(obj) {
return (
typeof obj[Symbol.iterator] === "function" &&
typeof obj["next"] == "function"
);
}
const __run__ = ${typeof f === "function" ? function_stringify(f) : f};
self.onmessage = async function(e) {
const t0 = performance.now();
let result = await __run__(e.data);
if (typeof result !== "undefined") {
if (!isIterable(result)) result = [result];
for (const p of result) {
postMessage(typeof p !== "object" ? p : Object.assign(p, {_time: performance.now() - t0}));
}
close();
}
}`;
}
// On iOS, [generator].toString() doesn't give "function*" but "function". Fix this.
function function_stringify(f) {
let g = f.toString();
if (f.prototype && f.prototype.toString() === "[object Generator]")
g = g.replace(/function\*?/, "function*");
return g;
}
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
