This note considers use of domains to perform the pushy protocol style of stream processing. Keykos resume keys are enough like continuations to map to the values passed in register B in the proposed machine language protocol. (The preceding reference thinks continuations are only for functional programming, but this is not that!) Such Keykos values can be stored and used just once, as in the protocol. A pushy node is mapped to a domain. Downstream pointers from P nodes to P nodes are mapped to start keys. As domain code passes a character further downstream along with the continuation (B), the domain code would return to the downstream start key with a resume invocation, thus becoming available for the next character.
Variations on this lead to much higher multiprogramming.