;;;; A program that stops with something worth looking at in the frame.
;;;;
;;;; dev-break.flan proves an editor can find out *that* a program stopped and
;;;; choose a restart; this one is about what the frame holds while it is
;;;; stopped. One local of each shape the structural printer has an arm for —
;;;; a parameter, a string, a struct, a fixed array, a bool — plus one that is
;;;; bound only *after* the error, which is the case that must come back
;;;; refused rather than rendered: its slot is storage nothing has written yet.
(import agent "vendor:agent")

(defstruct Point [x f32  y f32])
(defstruct Boom [why i32])

(defn look [n i64  label string] i64
  (let [p    (Point {:x 1.5 :y 2.5})
        xs   [10 20 30]
        flag (> n 0)]
    (restart-case
      (do (error (Boom {:why 7}))
          ;; Never reached before the break, so [after] is a slot with nothing
          ;; in it: the frame records a null for it and this is what "not bound
          ;; yet" has to mean.
          (let [after (i64 99)] after))
      (carry-on [] 5))))

(defvar ticks i64)

(defn main [] i32
  (agent/start "/tmp/flan-dev-locals-fallback.sock")
  (print (look 3 "hello")) (println "")
  (dotimes [i 4000]
    (agent/wait 5)
    (set ticks (+ ticks 1)))
  0)