ref: 4ca9e2fd9c0213a83b79554dd76d3e19aa6adec7
dir: /test/stdopt-mk.myr/
use std
const f = {x
if x == 123
-> `std.Some 42
else
-> `std.None
;;
}
const main = {
var v
v = f(123)
match v
| `std.Some x: std.exit(x)
| `std.None: std.exit(123)
;;
}