;;;; Globals, 2-D fixed arrays, places, pointers, casts and match — the
;;;; milestone-2 surface calc-me does not reach.
(defconst rows 3)
(defconst cols 4)
(defvar grid [rows [cols i32]])
(defvar total i32)
(defconst pal [4 u32] [10 20 30 40])

(defstruct P [x i32  y i32])
(defstruct Line [a P  b P])

(defn bump [p (Ptr P)]
  (set (.x p) (+ (.x p) 1)))

(defn sum-grid [] i32
  (let [t 0  r 0]
    (while (< r rows)
      (let [c 0]
        (while (< c cols)
          (set t (+ t (at grid r c)))
          (set c (+ c 1))))
      (set r (+ r 1)))
    t))

(defn find [n i32] (Option i32)
  (if (> n 0) (Some (* n 2)) None))

(defn main [] i32
  (set (at grid 1 2) 7)
  (set (at grid 0 0) 5)
  (set total (sum-grid))
  (print total) (println "")                              ; 12
  (print (at pal 2)) (println "")                         ; 30
  (let [p (P {.x 1 .y 2})]                                ; :y omitted is zeroed
    (bump (addr p))
    (print (.x p)) (println "")                           ; 2
    (let [l (Line {.a p})]
      (print (.y (.a l))) (println "")))                  ; 2
  (print (/ 7 2)) (println "")                            ; 3   integer divide
  (print (/ (f64 7) 2.0)) (println "")                    ; 3.5 float divide
  (print (match (find 21) (Some v) v None 0)) (println "")           ; 42
  (print (match (find -1) (Some v) v None 99)) (println "")          ; 99
  (let [q (addr total)]
    (print (deref q)) (println "")                        ; 12
    (set (deref q) 123)
    (print total) (println ""))                           ; 123
  0)