// Value-carrying failable main `-> (int, !)` (ERR step E4.2). The entry-point
// wrapper extracts the `{value, error}` tuple main returns: on success it exits
// with the integer value (truncated to u8, like a plain integer main); on an
// escaping error it prints the header + trace to stderr and exits 1 (the same
// reporter as the pure `-> !` form — see 244). This run takes the success path.
// Expected exit code: 64 (the returned value).

#import "modules/std.sx";

ParseErr :: error { Empty, BadDigit };

inner :: (n: i32) -> (i32, !ParseErr) {
    if n == 0 { raise error.Empty; }
    if n < 0 { raise error.BadDigit; }
    return n * 2;
}

main :: () -> (i32, !ParseErr) {
    v := try inner(32);                      // succeeds → v = 64
    print("v = {}\n", v);
    return v;                                // success → exit code 64
}