The comparison should be updated to Swift 3. Swift syntax is more intuitive and readable than Scala. A common mistake in language design is to depart from C syntax, without substantial gain. For example, replacing {}, &&, || with other things. Swift strikes a great balance between intuition and innovation.

Some of these comparisons aren't great. The "Variable Number Of Arguments" example is better expressed in Swift with "reduce", and it's really comparing "summing an array", the varargs aspect is a minor detail of the example. The "Idiomatic Scala" example doesn't even declare a function with varargs! (yes, it uses one, but that's not really the point)

The Swift function in the protocols example doesn't need to be generic, as the protocol doesn't have any associated types, and really ought to be a protocol extension regardless.

Wow. They're basically identical. Scala has a bit less boilerplate sometimes, but it's also older, so I guess Swift will get syntactical sugar to catch up in time.