> I still don't see what's functional about this. Functional is about higher-order functions, currying, and so on. I'm not positive most business logic profits

> I still don't see what's functional about this. Functional is about higher-order functions, currying, and so on. I'm not positive most business logic profits from that. What you describe can be achieved by swapping out a number (or more generally, data). And a discussion about composing functions is a discussion about higher-order functions. Why is that not FP?