Here is a pure swift implementation of dynamic class types. It does require the classes to extend the same protocol.

But if you combine a swift enum with RegExp matches and add ($n ) to your capture groups you can simulate named capturing groups.

In order to support GradientLine it was necessary to go all the way down to the core , namely Quartz which is part of CoreGraphics. So currently implementing a routine to support GradientLine Directly.

There are a couple of ways to do it

Delegation vs NsNotificationCenter vs Custom Event system