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Comment by lxe | Hacker News Reader

I'm still not a fan of the async iterator API example for server handlers:

    for await (const conn of Deno.listen({ port: 4500 })) {
      (async () => {
        for await (const { respondWith } of Deno.serveHttp(conn)) {
          respondWith(new Response("Hello World"));
        }
      })();
    }

It's hard to reason, and ugly with that async iffe in the middle adding layers of nesting and bf-like `})();` junk.

I think the event subscription API is much easier on the eyes and the mind.

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I'm curious why the IIFE is even necessary in this case. There is already a top level await in the `for await` right?

Looks fine IMHO once the IFFE is removed:

  for await (const conn of Deno.listen({ port: 4500 })) {
        for await (const { respondWith } of Deno.serveHttp(conn)) {
          respondWith(new Response("Hello World"));
        }
    }

Edit: Oh is it so it runs in concurrently and avoids the synchronous handling?

Yes I think the IIFE is there to avoid the inner loop blocking the outer loop.

I think it looks better with the IIFE factored out into its own function:

    async function serve(conn) {
      for await (const { respondWith } of Deno.serveHttp(conn)) {
        respondWith(new Response("Hello World"));
      }
    }

    for await (const conn of Deno.listen({ port: 4500 })) {
      serve(conn);
    }

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