;;;; What [flan dev] launches: a program with a loop, a function to redefine,
;;;; and a way to stop.
;;;;
;;;; It names no socket. Under [flan dev] the daemon has already decided where
;;;; it wants to talk to this program and says so in FLAN_AGENT_SOCKET — which
;;;; overrode whatever the source named anyway — so the argument was only ever
;;;; a value nothing read. This is the shape a program should be written in,
;;;; and the whole daemon block in test_dev.ml runs against it, so a delivery
;;;; landing there is the zero-argument form working end to end.
(import agent "vendor:agent")

(defonce ticks i64)

;;; A condition and something that signals it, so that a body typed in later
;;; can establish a handler and transfer past this frame — spec-conditions.md
;;; §6. It is here rather than in the evaluated form on purpose: the guard that
;;; forwards the transfer has to be one the *host* was compiled with.
(defstruct Missing [id i32])

(defn probe [] i64
  (signal (Missing {.id 1}))
  0)

(defn step [] i64
  (set ticks (+ ticks 1))
  ticks)

(defn main [] i32
  (agent/start)
  (print (step)) (println "")
  (while (= (agent/wait 100) 0) 0)
  (print (step)) (println "")
  (while (= (agent/wait 100) 0) 0)
  (print (step)) (println "")
  (while (= (agent/wait 100) 0) 0)
  (print (step)) (println "")
  0)