ref: da04ee7b0352fe9d2605481d643ffff09588f99b
dir: /test/uconinit.myr/
use std type u = union `A `B `C int ;; const a = [`A, `B, `C 123] const main = { for v in a match v | `A: std.put("A ") | `B: std.put("B ") | `C x: std.put("C {}\n", x) ;; ;; std.put("\n") }