[mjevans]

I think that inheritance can have a place. It makes a lot of sense when writing //small variations// on an otherwise rich inner class. Small variations might include layering on a different input or output mechanism, or possibly handling 'extra' data that the object stores but previously did not modify.

[wereHamster]

You can achieve the same with composition or parametrisation. Both of which are the only tools in a functional language.

[mpweiher]

You can achieve the same in any Turing complete language.

However, composition and parametrization require up-front design and are usually only viable for large-ish variations.

As the parent said, inheritance handles the case of refinement, that is, programming by difference, which composition and parametrization handle with difficulty (if planned for) or not at all (if not planned for).

The bad rap inheritance gets is that it is often misused in places where composition or parametrization were appropriate. But that's just the old "it hurts when I poke myself in the eye with a sharp stick": don't do that.

http://www.metaobject.com/papers/Diplomarbeit.pdf

[contravariant]

If you include interfaces you've essentially split inheritance into separate parts. Which isn't necessarily a bad idea.