fan-out is necessary for DX
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I've reached the conclusion that we need to use a programming language/notation that makes it equally easy to use asynchronous message sends and function calls, so that we may choose appropriately. It is not good enough to make function calls convenient, but, to require extra work to enact async message sending.
programmingsimplicity.substack.com/p/layered-abstraction?r=1egdky
2026-01-23
Paul Tarvydas have you ever heard of bigraphs? They are the culmination of Robin Milner's work on process calculi, which are the more mathematical/algebraic alternative to the Actor Model. The way Milner draws bigraphs is quite similar to your diagrams, and they are also motivated by applications to distributed computing.
Pablo Donato Thanks! I will look into it some more. aside: Actors are not like PBP diagrams, but, maybe bigraphs are. The issue is: when implementing fan-out, where is the routing information stored? In Actors, you have to hard-wire knowledge of the destinations into the sender's code, whereas with PBP the routing information is notationally lifted into the parents' code. Bigraphs seem to get this more right. Technically this appears to be just a small issue, but it results in a major DX issue. Hard-wiring prevents LEGO-like plugability.