NetService NutHouse

Michael, have you tried disabling the bridging successfully? This still crashes for me, but I'm not sure whether you mean something different:

let txtRecord = NetService.dictionary(fromTXTRecord:txtRecordData) as NSDictionary

@Jeff Yes, I tried this in a playground:

let txtData = NetService.data(fromTXTRecord: ["foo": Data()])
let dict = NetService.dictionary(fromTXTRecord: txtData) as NSDictionary

It crashes without the cast. With the cast, it doesn’t crash, and the result successfully casts to [String: NSNull]. I’d be interested to know what test data you’re using.

It took me a while to figure out, but the actual data from NetService is not exactly what you expect:

let bytes:[UInt8] = [3, 102, 111, 111]
if let stringFromBytes = String(data: Data(bytes: bytes), encoding: .utf8) {
    let txtData = NetService.data(fromTXTRecord: [stringFromBytes: Data()])
    let dict = NetService.dictionary(fromTXTRecord: txtData) as NSDictionary
    print(dict)
}

$ dns-sd -R 'My Service Name' _myservice._tcp local 4567 foo

Correction: The problem in my last code was that txtData was 0 bytes, and NetService.dictionary(fromTXTRecord: txtData) crashes with empty data. In contrast, CFNetServiceCreateDictionaryWithTXTData returns nil with empty data. This is still a problem, because NetService.dictionary(fromTXTRecord:) is supposed to be nonnull.

So you are correct, NetService.dictionary(fromTXTRecord: txtData) as NSDictionary doesn't crash, as long as you guard against giving it 0 bytes of data.

So to clarify, the test should be something like this:

let bytes:[UInt8] = [3, 102, 111, 111]
let dict = NetService.dictionary(fromTXTRecord: Data(bytes: bytes)) as NSDictionary

which doesn't crash.

@Jeff It looks like if you give it empty data, it returns nil. So you can just use:

let dict = NetService.dictionary(fromTXTRecord: Data()) as NSDictionary?

to not crash.

Yes, that would work. All of the crashing is because Swift trusts the Objective-C annotations, but in this case the Objective-C annotations for both generics and nullability fail to match the implementation.

Gluing a dynamic system onto another system is doable. Gluing a static system onto a dynamic system is endless stream of pain points both large and small that no amount of snake oil will cure.

Swift is the hole into which Apple has dug Cocoa. The least worst thing they could do now is hurry up and finish burying it. The sooner old messy bridged Cocoa APIs are superseded by modern clean Swift APIs that play to the strengths of Swift instead of the weaknesses of its ObjC bridge, the sooner we can all get back to the slightly more important business of actually making and selling competitive product.

(See also: the Python 2 to 3 migration debacle; the Java-Cocoa bridge; every tail that wagged the dog ever.)