On Saturday, 1 March 2014 at 13:54:49 UTC, Araq wrote:
Araq: could you list the problems you see in the OO world?
I could list the problems, but that would fill books. So, I'll
focus on a single aspect instead here: "Favour composition over
inheritance". This is commonly regarded as the better solution
(and I agree with it btw). Ok, fine, so we favour composition
and don't use inheritance. If we don't use inheritance we have
no subtyping either
Favouring composition over inheritance means not to create too
deep class hierarchies. It doesn't mean not to make use of
inheritance anymore at all. The deeper a class hierarchy the more
inflexible: if you change the parent class of a class in a big
hierarchy tree you break a lot of things (all subclass of the
classs with the changed parent class are affected). So create
light hierarchies and then go with composition. Overriding
inherited methods is still a great way to achieve flexibility
without breaking encapsulation.
