Clean up and comment data URI implementation

Author: developit

greenlet.js

@@ -11,10 +11,11 @@ export default function greenlet(asyncFunction) {
 
 	// Create an "inline" worker (1:1 at definition time)
 	const worker = new Worker(
+		// Use a data URI for the worker's src. It inlines the target function and an RPC handler:
 		'data:,$$='+asyncFunction+';onmessage='+(e => {
 			/* global $$ */
 
-			// Invoking within then() captures exceptions in userFunc() as rejections
+			// Invoking within then() captures exceptions in the supplied async function as rejections
 			Promise.resolve().then(
 				$$.bind.apply($$, e.data)
 			).then(
@@ -31,36 +32,6 @@ export default function greenlet(asyncFunction) {
 				er => { postMessage([e.data[0], 1, '' + er]); }
 			);
 		})
-
-		/*
-		// The URL is a pointer to a stringified function (as a blob object)
-		URL.createObjectURL(
-			new Blob([
-				'$$=', asyncFunction,
-				// Register our wrapper function as the message handler
-				';onmessage=',
-				// userFunc() is the user-supplied async function
-				e => {
-					// Invoking within then() captures exceptions in userFunc() as rejections
-					Promise.resolve().then(
-						$$.bind.apply($$, e.data)
-					).then(
-						// success handler - callback(id, SUCCESS(0), result)
-						// if `d` is transferable transfer zero-copy
-						d => {
-							postMessage([e.data[0], 0, d], [d].filter(x => (
-								(x instanceof ArrayBuffer) ||
-								(x instanceof MessagePort) ||
-								(x instanceof ImageBitmap)
-							)));
-						},
-						// error handler - callback(id, ERROR(1), error)
-						er => { postMessage([e.data[0], 1, '' + er]); }
-					);
-				}
-			])
-		)
-		*/
 	);
 
 	/** Handle RPC results/errors coming back out of the worker.