Expand description
The compiled program and the wire it speaks on, from beck_host — the half of this platform
that is program-shaped rather than machine-shaped, and that a browser tab therefore also runs
(docs/17-playground.md §17.2). Re-exported at the paths
they have always had: beck_rt::program::Runtime is beck_host::program::Runtime.
The socket protocol: one connection multiplexing patches down and commands up (§5.1).
Resumption is the load-bearing part. A subscriber reconnects with (subscription, seq) and the
server replays the gap rather than re-rendering the world — which is what makes a deploy, or a
dropped train tunnel, cost one small patch instead of a full page.
One rule Phase 0 learned the hard way and §18.7 item 5 says to carry forward: the ack tells
you the command landed; the frame tells you where your view stands, and the two are different
facts. A command whose net effect is invisible in a subscriber’s own view produces an empty
diff and therefore no frame, so a client waiting for “the patch for my command” would wait
forever. up_to_date is the answer, and it is sent only to a client waiting on its own
command — never to idle ones, because a message per idle subscriber per event is precisely the
fanout cost this design exists to avoid.
Structs§
Enums§
- Client
Msg - Resumption
- How a subscription was (re)established.