Timeout

pub const Timeout = union(enum) {
    /// `.none` will wait forever
    none,
    duration: Clock.Duration,
    deadline: Clock.Timestamp,

    pub const Error = error{Timeout};

    pub fn toTimestamp(t: Timeout, io: Io) ?Clock.Timestamp {
        return switch (t) {
            .none => null,
            .duration => |d| .fromNow(io, d),
            .deadline => |d| d,
        };
    }

    pub fn toDeadline(t: Timeout, io: Io) Timeout {
        return switch (t) {
            .none => .none,
            .duration => |d| .{ .deadline = .fromNow(io, d) },
            .deadline => |d| .{ .deadline = d },
        };
    }

    pub fn toDurationFromNow(t: Timeout, io: Io) ?Clock.Duration {
        return switch (t) {
            .none => null,
            .duration => |d| d,
            .deadline => |d| d.durationFromNow(io),
        };
    }

    /// Waits until the timeout has passed.
    ///
    /// See also:
    /// * `Io.sleep`
    /// * `Clock.Duration.sleep`
    /// * `Clock.Timestamp.wait`
    pub fn sleep(timeout: Timeout, io: Io) Cancelable!void {
        return io.vtable.sleep(io.userdata, timeout);
    }
}