It would be difficult (or perhaps impossible) to type all of Erlang's message passing features, so we reduced scope to not include distributed message passing or hot upgrades- so the types of all actors in the system can be known up front in order to be checked.
In practice this is enough for the vast majority of applicatinos, and messages with runtime checks (like in regular Erlang) can be used for the other situations if required.
In practice this is enough for the vast majority of applicatinos, and messages with runtime checks (like in regular Erlang) can be used for the other situations if required.