3 ms·

Well respectfully, you provided the original project spec as an example of where objects were required, and I demonstrated that no, they mostly weren't. I agree

by dTal 5y ago

Well respectfully, you provided the original project spec as an example of where objects were required, and I demonstrated that no, they mostly weren't. I agree that it's unproductive for you to keep adding things to the spec so that I can demonstrate that nope, you still don't need objects to do all that. All that objects are, are functions glued to data. That's it. Whether or not you choose to glue them together, the behavior of the dog lies in the functions, and the state of the dog lies in the data. Frankly, your examples seem to lead away from objects - how will another developer add the ability to heal dogs, for instance? They can't change the class definition, so they'll have to do something awful like subclass it into HealableDog(), which doesn't interoperate with all the existing dog code at all. Meanwhile, if 'dog' is simply a big ol' struct of data, they can write a function heal(dog) and call it a day. I highly recommend the first part of this video, which explains the composability problems with objects very well - with dogs and cats even! https://www.youtube.com/watch?v=kc9HwsxE1OY https://www.youtube.com/watch?v=kc9HwsxE1OY

throwaway889900 5y ago
Make Dog implement Healable, duh.
- dTal 5y ago
  The original author can do that. Another author cannot add that functionality later, as a library. The can only define a new kind of dog.
  - throwaway889900 5y ago
    Subclass Dog into MyDog, which is exactly the same as Dog. From there, use and modify MyDog as though you would be modifying Dog. Any class that references base class Dog isn't modifiable, but any future work you can use MyDog instances to get all the functionality you need (with some ugly casting). There are other solutions as well.
ozim 5y ago
Link to YouTube was really nice. I would not agree that one cannot change the class definition as it really depends on the system one is writing. I change class definitions on daily basis in business line applications. If I would be making frameworks then maybe I would not do that so often.

by dTal 5y ago

throwaway889900 5y ago

Make Dog implement Healable, duh.

dTal 5y ago
The original author can do that. Another author cannot add that functionality later, as a library. The can only define a new kind of dog.
- throwaway889900 5y ago
  Subclass Dog into MyDog, which is exactly the same as Dog. From there, use and modify MyDog as though you would be modifying Dog. Any class that references base class Dog isn't modifiable, but any future work you can use MyDog instances to get all the functionality you need (with some ugly casting). There are other solutions as well.

ozim 5y ago

Link to YouTube was really nice. I would not agree that one cannot change the class definition as it really depends on the system one is writing. I change class definitions on daily basis in business line applications. If I would be making frameworks then maybe I would not do that so often.