I think about using OOP only in terms of the structure of my data. Is my data more easily represented using actual pointer loops or is it a tree structure? Wit

I think about using OOP only in terms of the structure of my data. Is my data more easily represented using actual pointer loops or is it a tree structure? With immutable objects you can't easily create longer loops in data (self-reference is okay though). Is my data a tree of some notion, I always go for FP.