In order to cut down on (and keep low) object allocations when creating actors, there should be two varieties:

• the basic Actor, which works using overriding methods and even does not allocate a closure for “receive”
• the fancy Actor, which provides the low-level methods internally and fills in behavior a DSL (à la “uponBirth { ... }”, “uponRestart { ... }”, “become { ... }”, etc.)

The reason is that we will spawn many basic actors when re-implementing ask(), and those don’t need a fancy DSL, not even the current receive().

We could keep the current receive method supported (defaulting to null) and provide a default receive(Any):Boolean which delegates to that. Then everyone could live on happily in peace.