Comment by gdxhyrd
6 years ago
In the linked blog post they mention size explicitly:
> ABI stability for Apple OSes means that apps deploying to upcoming releases of those OSes will no longer need to embed the Swift standard library and “overlay” libraries within the app bundle, shrinking their download size; the Swift runtime and standard library will be shipped with the OS, like the Objective-C runtime.
For new UI backends you don't need a different interface, you provide the new UI under the old interface. If your new elements have new behavior you will need to update your app anyway.
Sorry, you are correct, I was imprecise.
"ABI stability" is about defining an ABI. "ABI resilience" is defining how libraries can evolve in a binary compatible way. Stability is a precursor to resilience.
Apple would like to write libraries in Swift, but those libs have to participate in an ABI that is stable (so apps can use them) and resilient (so Apple can evolve them without breakage).
> For new UI backends you don't need a different interface, you provide the new UI under the old interface
The challenge is how to provide new UI features without breaking existing apps. For many UI frameworks (the web in particular) the compiler/runtime has a global view and can sort it out. But if both the app and library are separately compiled, the problem becomes trickier.