How to Write a Functional Programming Function

The first thing you write in a function is the return. It often helps you work backwards from there, rather than kind of like starting with just an empty function and then hoping you get to the return that you want. I would also say like leave lots of comments if someone less experienced than you can understand what you're doing. One file, one function makes it way easier. Don't have a file with like 50 utility functions in it.