ref: e359b66fa9e58e8806e0df26d28feca87db7c7a6
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)
;;
}