Languages built on the BEAM VM like Erlang and Elixir support concurrency at the runtime level, though it's up to you to specify when you want to run something in parallel. Or am I missing why they don't fulfill your requirements?
I'm not sure if it's desirable to parallelize code automatically, as in many cases you do need at least _some_ parts of the code to run synchronously. But it's an interesting thought experiment to have parallelism be the default instead of opt-in.
I'm not sure if it's desirable to parallelize code automatically, as in many cases you do need at least _some_ parts of the code to run synchronously. But it's an interesting thought experiment to have parallelism be the default instead of opt-in.