Re: Judge a book by it's author

[robot_tourist]

Inheritance is an essential part of any Object Oriented Programming language. Some languages implement it better than others, some programmers implement it better than others, but I don't know of a better way (although I have been out of university for a couple of years now).

[systems]

First not all object systems implement or provide inheritance for example check snit
In my understanding inheritence serve two purposes
1. Gives you a mean to say that an object have more than one type (play more than one role, thus inheritance and multiple inheritance), this is only useful if you ever need to test an object type, which as far as I only required by static languages, and usually forwned upon in dynamic languages
2. Give a default value for the method the object inherited (unless you are inheriting from an abstract class)
I think you find can other ways to achive both requirements without inheritance. Which makes inheritance an implementation detail, a technique not a requirement.
I prefer to focus on the requirement, and consider the different ways and alternatives to achieve it.

[robot_tourist]

IMO your point number two is pretty fundamental to object orientation and is a very good one-line synopsis, you take a class and extend it by adding functionality, but keeping all the stuff you don't want to re-invent. And it gives you a nice tree to draw when you are designing your system.

Personally, I can't think of a good reason not to use inheritance.

[chromatic]

Personally, I can't think of a good reason not to use inheritance.

I can. It encourages code reuse along the wrong lines, caring more about position in an arbitrary (and quite possibly wrong hierarchy) than about the capabilities of the class.

That's why Perl 6 encourages the use of roles.