ref: 6fb7d34b848c598e6398f960dc0a7e240e09a6f5
dir: /test/uconinit.myr/
use std
type u = union
`A
`B
`C int
;;
const a = [`A, `B, `C 123]
const main = {
for v : a
match v
| `A: std.put("A ")
| `B: std.put("B ")
| `C x: std.put("C {}\n", x)
;;
;;
std.put("\n")
}