[eecc]

I think what he means is that everything in Haskell is "async" because the language runtime is lazy and types can encode parallelism: monads and functors fro sequential, blocking code, while applicatives for independent code.

Not sure if it's actually correct though.

[k_bx]

Nothing to do with laziness. It just means you cannot accidentally call blocking (sync) operation from a lightweight (async) thread and block a whole bunch of other lightweight threads like in Rust, C#, or other languages with explicit “async” keyword