Actually, some authors define objects as functions with an internal state. In that sense, objects derive from functions. For instance, in OCaml, the function "

Actually, some authors define objects as functions with an internal state. In that sense, objects derive from functions. For instance, in OCaml, the function "counter" defined as: "let counter = let x = ref 0 in fun _ -> x := !x + 1; !x ;;" is an object with one method that increments and returns the value of a counter. In my opinion, OOP is intrinsically more complicated that FP because you can't really avoid complex patterns even to do simple things. An example that comes to mind is the "Visitor" pattern. To me, it requires more mental gymnastic than what is found in most functional programs. It amounts to mixing higher order and functions with state which is something you try to avoid in FP. But I admit that I'm not well-versed in OOP. I've always found it complicated. Not Objects per se, but design of big programs using classes with complex relations, UML, design patterns and so on...