// What does using actually clean up?
// Teaching excerpts; see the explanation and boundaries on the episode page.

// It calls a method when the block ends.
const resource = {
  [Symbol.dispose]() {
    events.push("dispose");
  }
};

// Return does not skip cleanup.
function job() {
  using r = resource;
  events.push("work");
  return "done";
}
events.push(job());

// The compiler adds helpers and finally.
// Emitted structure, shortened
try {
  // Register resource and do work
} finally {
  __disposeResources(env_1);
}

// No dispose method? Use try finally.
const file = openFile();
try {
  return read(file);
} finally {
  file.close();
}