Yep, going from arbitrary recursion to `fold` to `reduce` to `flatMap` to `map`, you're actually discarding power and expressiveness. But the good news is that

Yep, going from arbitrary recursion to `fold` to `reduce` to `flatMap` to `map`, you're actually discarding power and expressiveness. But the good news is that you're exchanging raw expressiveness for a tool that fits the job at hand more precisely.