;;;; A program that stops on its own while an evaluation is in flight.
;;;;
;;;; Setting [go] from the editor starts it: the loop sees it, sleeps without
;;;; polling for longer than a module takes to build, and then signals. An
;;;; expression evaluated just after [go] is therefore waiting in the ring
;;;; when the program's own break is entered, and runs inside that break's
;;;; loop. The stop is the program's and the value is the expression's.
(import agent "vendor:agent")

(declare-c usleep [us i32] i32 "usleep")

(defstruct Late [])

(defonce go i64)

(defn main [] i32
  (while (= go 0)
    (agent/wait 5))
  (usleep 1500000)
  (restart-case
    (do (error (Late {})) 0)
    (carry-on [] 0)))