> Basically: I need a Car Object with these exact fields vs give me a thing with the field "foobar" that contains something that I can concatenate with another things.
Um, that's another matter entirely. Polymorphism. Mainstream statically typed programming languages until recently knew exactly one type of polymorphism based on objects, classes and interfaces. It is object-level polymorphism that lies at hear of OOP.
This form of polymorphism is easy to implement in compiler or interpreter, but it also is very limited in expressiveness. So proper functional languages use parametric object-level and function-level polymorphism and allow dictionary passing (both implicit and explicit). This approach filters into mainstream programming language: generics in Java, templates in C++ and so on.
Um, that's another matter entirely. Polymorphism. Mainstream statically typed programming languages until recently knew exactly one type of polymorphism based on objects, classes and interfaces. It is object-level polymorphism that lies at hear of OOP.
This form of polymorphism is easy to implement in compiler or interpreter, but it also is very limited in expressiveness. So proper functional languages use parametric object-level and function-level polymorphism and allow dictionary passing (both implicit and explicit). This approach filters into mainstream programming language: generics in Java, templates in C++ and so on.