[Kinrany]

Ideally:

1. The compiler would be able to turn a subset of async code into sync code with no runtime cost

2. Awaiting would be the default, with `.await` deprecated and special syntax for getting a raw future instead

That way most code would look the same regardless of being executed synchronously or asynchronously, with exceptions for evaluating multiple expressions in parallel and such.

But #2 probably implies lazy evaluation semantics for all expressions!