# arena_defaults.ludic - a field's default (`items: []int = new []int`) is one expression, made at every
# `new` of its record: here for a record a pool keeps (made in frame 3, the arena running) and for a
# frame's temporary. It must stay on the heap for both. Built with --arena and poisoned on every
# reset, it prints `497 124747`.
program ArenaDefaults {
  property Bag { items: []int = new []int, n: int = 0 }
  function temp_sum(f: int) -> int {
    let t = new Bag
    t.n = f
    return t.n
  }
  function step(held: []Bag, f: int) -> int {
    if f == 3 { push(held, new Bag) }
    if len(held) > 0 { push(held[0].items, f) }
    return temp_sum(f)
  }
  entry {
    let held = new []Bag
    var t = 0
    for f in 0 .. 500 {
      t += step(held, f)
      Mem.frame()
    }
    var sum = 0
    for i in 0 .. len(held[0].items) { sum += held[0].items[i] }
    print(`{len(held[0].items)} {sum}`)
  }
}