;;;; 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-i64 (i64 total)) (newline)                       ; 12
  (print-i64 (i64 (at pal 2))) (newline)                  ; 30
  (let [p (P {:x 1 :y 2})]                                ; :y omitted is zeroed
    (bump (addr p))
    (print-i64 (i64 (.x p))) (newline)                    ; 2
    (let [l (Line {:a p})]
      (print-i64 (i64 (.y (.a l)))) (newline)))           ; 2
  (print-f64 (f64 (/ 7 2))) (newline)                     ; 3   integer divide
  (print-f64 (/ (f64 7) 2.0)) (newline)                   ; 3.5 float divide
  (print-i64 (i64 (match (find 21) (Some v) v None 0))) (newline)    ; 42
  (print-i64 (i64 (match (find -1) (Some v) v None 99))) (newline)   ; 99
  (let [q (addr total)]
    (print-i64 (i64 (deref q))) (newline)                 ; 12
    (set (deref q) 123)
    (print-i64 (i64 total)) (newline))                    ; 123
  0)