I haven't used the visitor pattern in OOP in over 10 years and I write lots of code. There are many other better solutions to the expression problem than visitors. I don't bother with design patterns much or UML at all. I do mix my style up with FP when appropriate, but OOP is my dominant organizing principle.
OOP really is just about object thinking, just like FP really is about thinking in terms of functions. All the other baggage in either paradigm is quite optional.
OOP really is just about object thinking, just like FP really is about thinking in terms of functions. All the other baggage in either paradigm is quite optional.