-- Runtime residual check: `get` on a `map` with a key that isn't present
-- traps KEY (docs/plan/oop-vm/08-builtin-surface.md's `get` row: "a
-- missing key traps KEY"). Unprovable at compile time -- the key is a
-- runtime `Text` value -- so it traps rather than failing to compile:
-- the hybrid boundary's runtime half.
--
-- Written as `get(...)` on purpose: the two map reads differ. `get(m, k)`
-- ASSERTS the key is there and traps KEY when it isn't (this fixture);
-- `m[k]` is the OPTIONAL read and yields nil for a missing key, which is
-- what makes `let v = m[k]; if v != nil { ... }` the ordinary lookup idiom
-- (the driving workload's own header lookup). Before 2026-08-14 both
-- spellings trapped, and this fixture used the sugar.
class Catalog {
  prices: map<Text, Int>
}

fn main() {
  let c = Catalog { prices: map_new() }
  set(c.prices, "mug", 499)
  print_int(get(c.prices, "shirt"))
}