Swift gems for creating reliable, concurrent OS X desktop apps

I've used it in a few projects, and it makes dealing with async things feel surprisingly natural:

    getLocation()
        .then { apiRequest(params, location: $0) }
        .then { json -> () in
            for result in json["results"] {
                display(result)
            }
        }
        .catch { showError($0) }

[1]: https://gist.github.com/Sidnicious/93d2a8db1266e2fd239c

[2]: https://gist.github.com/Sidnicious/69df2c483aadc08bda4f

[3]: https://gist.github.com/Sidnicious/99b099d9b6f2ecb9e383

[1]: https://github.com/antitypical/Result

Or, you could just make a logging serial queue that you send all log messages to; that way there's no risk of activity on the main thread slowing down your logging. In (Obj-)C:

    static queue_t queue;
    void log (NSString *message) {
        static dispatch_once_t onceToken;
        dispatch_once(&onceToken, ^{
            queue = dispatch_queue_create("logging", DISPATCH_QUEUE_SERIAL);
        });
        dispatch_async(queue, ^{
            NSLog(message);
        });
    }