Waiter<T> class

Manages a collection of operations for deferred, batched execution.

Unlike Future.wait, which requires a list of already-running Future instances, a Waiter collects functions (operations) that have not yet been executed.

This allows you to build up a queue of tasks from different parts of your application and then run them all at once by calling wait.

{@tool snippet}

final waiter = Waiter<String>();

// Define tasks without running them.
waiter.add(() => 'Sync task complete');
waiter.add(() async {
  await Future.delayed(Duration(milliseconds: 20));
  return 'Async task complete';
});

// Execute the entire batch.
final results = await waiter.wait();
print(results); // (Sync task complete, Async task complete)

{@end-tool}