3 ms·

OOP is different things to different people. While I agree with you that OOP != inheritance, I believe that polymorphism ∈ OOP and inheritance is a part of poly

by samg_ 16y ago

OOP is different things to different people. While I agree with you that OOP != inheritance, I believe that polymorphism ∈ OOP and inheritance is a part of polymorphism.

loup-vaillant 16y ago
I don't follow you here. Are you saying that inheritance is mandatory to OOP? (I don't agree nor disagree. I'd just like to know what you mean.)
- barrkel 16y ago
  Polymorphism is often implemented as at least inheritance of interface in statically typed languages. Without polymorphism you don't get dynamic dispatch, especially open to extension at runtime.
- samg_ 16y ago
  I am not saying that inheritance is mandatory to OOP. I think "mandatory" is too strong of a word here. As I said, OOP means different things to different people and I am okay with that. Speaking for myself, OOP is a way to orchestrate programming on a large scale. To grow software without growing the frequency, severity, and difficulty of bugs and without growing costs associated with new features is the desired result. Component-ized architecture takes great steps to achieve this result. For this reason, I view OOP as being some combination of: message passing, encapsulation, and polymorphism. I do not believe this is a complete view of OOP, nor that there is no viable alternative view of OOP.
tkahn6 16y ago
Ad hoc polymorphism ∈ OOP Parametric polymorphism ∈ FP
vog 16y ago
I disagree. Polymorphism and inheritance are separate concepts. Yes, some statically typed languages like C++ and Java enforce certain inheritance constraints via classes or explicit interfaces before you can use polymorphism. But almost all dynamically typed languages allow for ad-hoc polymorphism. For instance, in Python this is called "duck typing". Just because two objects provide a "foo()" method doesn't mean they are in any inheritance relation to each other. But polymorphism should still work.

by samg_ 16y ago

OOP is different things to different people. While I agree with you that OOP != inheritance, I believe that polymorphism ∈ OOP and inheritance is a part of polymorphism.

loup-vaillant 16y ago

I don't follow you here. Are you saying that inheritance is mandatory to OOP? (I don't agree nor disagree. I'd just like to know what you mean.)

barrkel 16y ago
Polymorphism is often implemented as at least inheritance of interface in statically typed languages. Without polymorphism you don't get dynamic dispatch, especially open to extension at runtime.
samg_ 16y ago
I am not saying that inheritance is mandatory to OOP. I think "mandatory" is too strong of a word here. As I said, OOP means different things to different people and I am okay with that. Speaking for myself, OOP is a way to orchestrate programming on a large scale. To grow software without growing the frequency, severity, and difficulty of bugs and without growing costs associated with new features is the desired result. Component-ized architecture takes great steps to achieve this result. For this reason, I view OOP as being some combination of: message passing, encapsulation, and polymorphism. I do not believe this is a complete view of OOP, nor that there is no viable alternative view of OOP.

tkahn6 16y ago

Ad hoc polymorphism ∈ OOP Parametric polymorphism ∈ FP

vog 16y ago

I disagree. Polymorphism and inheritance are separate concepts. Yes, some statically typed languages like C++ and Java enforce certain inheritance constraints via classes or explicit interfaces before you can use polymorphism. But almost all dynamically typed languages allow for ad-hoc polymorphism. For instance, in Python this is called "duck typing". Just because two objects provide a "foo()" method doesn't mean they are in any inheritance relation to each other. But polymorphism should still work.