The problem is that Scala generates very big jar files, which is why the only couple of Scala Android applications I've ever seen are toy apps. There is no doubt that any more sizeable project will blow up Dalvik's various restrictions like is already happening with Scala apps without ProGuard.
There's also the fact that Typesafe doesn't care about Android so even if your current app works on Android, a future version of the compiler might make it blow up on the phone after you recompile it.
Unfortunately, the Ceylon team doesn't seem to be interested in supporting Android either.
Which leaves Kotlin, as a reasonable option for non-Java development on Android.
At any rate, don't expect any help from Google about Scala, they're not even supporting their own non-Java languages there (Go, Dart).
That's three strawmen in a row, none of them coming remotely close to addressing the point I made above.
The web (scala-internals, scala-users, stackoverflow) is filled with threads of people trying to run their Scala code on Android and being mystified by fatal errors from Dalvik or DEX generation simply dying on them.
Of course, but it's obvious they have zero desire to help support Scala on Android. First because they don't use Scala at all internally and second because even the languages that they created (Go, Dart) are not supported on Android. If Android ever officially supports a language other than Java, you can bet it will be one of these two.
By the way it seems that Dart is struggling to get any support at all within Google. Also, it's not statically typed and bringing it to the Android runtime might be much more effort. In short no, I wouldn't bet Go or Dart will be the solution, not unless these languages change a whole lot.
> The web (scala-internals, scala-users, stackoverflow) is filled with threads of people trying to run their Scala code on Android and being mystified by fatal errors from Dalvik or DEX generation simply dying on them.
No. Not even close.
There is exactly one known issue with Dalvik's limit of 64k methods, which requires running ProGuard before putting it on the app store (which is standard procedure for all apps).
There's also the fact that Typesafe doesn't care about Android so even if your current app works on Android, a future version of the compiler might make it blow up on the phone after you recompile it.
Unfortunately, the Ceylon team doesn't seem to be interested in supporting Android either.
Which leaves Kotlin, as a reasonable option for non-Java development on Android.
At any rate, don't expect any help from Google about Scala, they're not even supporting their own non-Java languages there (Go, Dart).