I wrote a custom keyboard using Swift. XCode stability was mostly OK. SourceKit crashed sometimes (disabling syntax highlight and autocomplete), but it didn't cause much headache.
The thing that bothered me most was that iOS app wrote with Swift was packaged with 8 MB runtime libraries, so it was like 100 kB of my code and 8 MB of swift runtime libraries which I didn't like at all.
I tried to learn how to write an OS X application with Swift and for some reason it became a nightmare, SourceKit keeps crashing and it wasn't possible to work at all. I guess I triggered some bug. I tried to investigate it, but without much success, I think that XCode will send those crash logs to Apple and may be things are already fixed.
Actually I'm not really sure that Swift is the language I want to use. Objective C is good enough. It's good old C which I like. It's very dynamic which I like. Cocoa, Cocoa Touch and other frameworks are made for Objective C, not for Swift. I didn't made a final decision whether I will invest into Swift, but probably (at least until Apple declares Objective C obsolete) I will just use Objective C. It has its problems, but it has its strength too.
The thing that bothered me most was that iOS app wrote with Swift was packaged with 8 MB runtime libraries, so it was like 100 kB of my code and 8 MB of swift runtime libraries which I didn't like at all.
I tried to learn how to write an OS X application with Swift and for some reason it became a nightmare, SourceKit keeps crashing and it wasn't possible to work at all. I guess I triggered some bug. I tried to investigate it, but without much success, I think that XCode will send those crash logs to Apple and may be things are already fixed.
Actually I'm not really sure that Swift is the language I want to use. Objective C is good enough. It's good old C which I like. It's very dynamic which I like. Cocoa, Cocoa Touch and other frameworks are made for Objective C, not for Swift. I didn't made a final decision whether I will invest into Swift, but probably (at least until Apple declares Objective C obsolete) I will just use Objective C. It has its problems, but it has its strength too.