This is indeed vastly inspired by Visual Format Language purposefully so, so that there's nothing more to learn. This actually does pretty much the same thing behind the hood. We can say this is just Apple's visual format on steroids.

Three reasons mostly motivated us : 1. having the compiler on our side and not just hope the string would parse fin at runtime. 2. Laying out Horizontal and Vertical layout at the same time 3. Having something readable cause readable == maintainable :)