;;;; (bytes s) copies, (bytes-view s) aliases — the ruling from the
;;;; INSERTIONSORT dogfooding session. The pin is the exact inverse of the
;;;; old aliasing: a write through the copy leaves the original string
;;;; printing unchanged, where the old (bytes s) either showed the write
;;;; through or trapped, depending on where the string's storage was.

(defonce frame Allocator)

(defn main [] i32
  ;; 1. The copy is writable and independent. Under the old reinterpret this
  ;;    second line printed ZNSERTIONSORT too (or the whole program died in
  ;;    .rodata) — the original staying itself is the whole of the change.
  (let [s "INSERTIONSORT"
        b (bytes s)]
    (set (at b 0) \Z)
    (println (string b))                     ; ZNSERTIONSORT
    (println s))                             ; INSERTIONSORT

  ;; 2. A literal's copy is writable — the exact form that used to segfault
  ;;    at -O0 and silently do nothing at -O2.
  (let [b (bytes "hi")]
    (set (at b 0) \H)
    (println (string b)))                    ; Hi

  ;; 3. The view still costs nothing and reads the string's own storage.
  (let [v (bytes-view "abc")]
    (println (len v))                        ; 3
    (println (at v 2)))                      ; 99

  ;; 4. (bytes s a) names the allocator, like (vec-new T a) and (clone v a):
  ;;    the copy's block comes from the arena and free-all reclaims it.
  (set frame (arena-new 4096))
  (let [b (bytes "arena" frame)]
    (set (at b 4) \A)
    (println (string b)))                    ; arenA
  (free-all frame)
  (arena-destroy frame)
  0)