have compute return instead of post

workers/compute.js

@@ -18,7 +18,8 @@ importScripts("./math.js")
 
 addEventListener("message", (message) => {
 	if (message.data.command === "compute") {
-		compute(message.data.queue, message.data.m);
+		const result = compute(message.data.queue, message.data.m);
+		postMessage(result);
 	}
 });
 
@@ -94,5 +95,5 @@ function compute(queue, modulus) {
 		result += modulus;
 	}
 
-	postMessage(result);
+	return result;
 }