I am developing a Swift to Kotlin translator that, as one might guess, depends a lot on small differences between versions of Swift. I recently started working on support for Swift 5.2, which for my purposes is quite different from Swift 5.1. It made me think that, while supporting either Swift 5.1 or 5.2 is easy, supporting both of them at the same time would be much harder.
Which makes me wonder: should I just drop support for Swift 5.1?
Specifically, I remember working on an iOS app during the Swift 2 -> Swift 3 transition, which was much more complicated. Our app spent months using only Swift 2 before we could dedicate the resources to make the transition properly. However, we now have reasonable source stability, ABI stability, etc, which makes things easier.
So I guess my real question is: are there any reasons why an iOS developer might want to spend a significant amount of time using Swift 5.1 before migrating to Swift 5.2? Any reasons it would be bad for me to "force" them to make the change?
For instance, I imagine there might be not only direct issues (such as source compatibility issues could have been) but also things like dependencies that won't compile properly, iOS versions that won't support Swift 5.2, issues with CocoaPods or Carthage, anything of that sort. In my mind source compatibility and ABI stability would take care of all that, but I wanted to be sure before making a decision.
Any help is appreciated!