Code that i wish didn't work

hell.hh

<?hh // strict

use namespace HH\Asio;

/**
 * Hate both the player, and the game.
 */
<<__EntryPoint>>
async function main(): Awaitable<void> {

  $call = async (): Awaitable<(
            function() : Awaitable<(
              function() : Awaitable<(
                function() : Awaitable<(
                  function() : Awaitable<(
                    function(): Awaitable<
                      string
                    >
                  )>
                )>
              )>
            )>
          )> ==> 
          async (): Awaitable<(
            function() : Awaitable<(
              function() : Awaitable<(
                function() : Awaitable<(
                  function() : Awaitable<
                    string
                  >
                )>
              )>
            )>
          )> ==> 
          async (): Awaitable<(
            function() : Awaitable<(
              function() : Awaitable<(
                function() : Awaitable<
                  string
                >
              )>
            )>
          )> ==> 
          async (): Awaitable<(
            function() : Awaitable<(
              function() : Awaitable<
                string
              >
            )>
          )> ==> 
          async (): Awaitable<(
            function() : Awaitable<
              string
            >
          )> ==> 
          async (): Awaitable<
            string
          > ==> "Hello, World\n";

  echo  Asio\join(
          Asio\join(
            Asio\join(
              Asio\join(
                Asio\join(
                  Asio\join($call())()
                )()
              )()
            )()
          )()
        );
}