I think you're responding to something I didn't (intend to) say.

It is a lot closer in the sense that it is less indirected and simpler. The Go team have circulated style guidance to groups I was part of about how to properly structure public APIs, and for example functional callbacks are nowadays preferred over channels.

I completely agree that Go is not designed to be Haskell, and I personally cringe every time I see a library of map/reduce/filter functions. I still prefer this over the older sins of stuff like ITreeIterator.

When I say "functional style" I don't mean lambda calculus. I mean more recent libraries don't tend to return interface-typed values as much or use channels as iterators.