diagram.d2

shape: sequence_diagram

S: {
  label: "Cloud Cell\n\n(handler namespace)"
}

NW: {
  label: "Nexus\nWorker\n\n(User's codebase)"
}

NSDK: {
  label: "Nexus\nSDK\n\n(nexus-rpc)"
}

NH: {
  label: "Nexus\nHandler"
}

type-check: "type-check time" {
  NW.00: "type-check operation impls\n\nE.g. Workflow.run signature\nmust match operation I/O types"
  NW.01: "type-check call sites\n\nE.g.fetchResult"
}

import-time: "import time" {
  NW.10: import MyService
  NW -> NSDK: service_decorator(\ninterface, impl)
  NSDK.1: validate impl\nagainst interface
}

start-worker: "start Worker" {
  NW.12: "Worker(nexus_services=[MyService()])"
  NW.14: "worker now has Service and \nOperation instances keyed by name\n\nthe Operation instances implement\nstart/cancel/getInfo/getResult interface"
}
handle-request: "handle request" {
  S -> NW: dispatch NexusTask
  NW -> NH: "lookup\nService and Operation\ninstance by name"
  NH.1: "start()"
}