Is there a reason behind the lack of such that you are aware of? I've made use of exceptions in some of my past programming efforts and see their use, so it's puzzling to me too that Swift would lack them.

One concern from two coworkers with Swift is readability of the code. The non mandatory need to declare what type a variable is may lead to less readable code. Readable in XCode where you can quickly see due to the tool, but not readable in a code merge tool for example.

So much of my own code reading is more from "is it merging right" between branches, and less following the flow of execution, so I lack the perspective to be able to know how much of a downside this may be. For my personal stuff, probably not a big deal. I just wonder how friendly Swift will be as a language for a team to make use of.