ref: ad1e9d7670685b9fffcdcacc9515b5919afa4c97
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)
;;
}