Learning Functional Programming in Go

What did that Map function do for us?  

The Map function abstracted the loop. We don't have to bother writing the same old range/for looping code. We simply pass in our original ints list and tell our functor to map that slice into a slice where each element is one greater than it was before. This is a lot like SQL, where we declare what data we want and let the database engine worry about how to get the data.