But in nu, it's more like you're just dealing with collections as in most programming languages. If your collection isn't amenable to being generated by a simple expression like a map or fold, then you have to create a collection, prep the collection to be what you want it to be, then you return it.
In that sense it's really different from both Powershell and traditional shells, and more like just using a traditional programming language. So in Nu I miss being able to just "yield" a value from anywhere without staging into a temporary collection first.