How many oo-functional hybrids are there?

Question

We're discussing oo-functional hybrids here, but I wonder, how many languages actually qualify for this name. Scala, Clojure, F#? Any more?

It'd be great to get one such language per answer, and a little explanation, why you think it is oo-functional hybrid.

Answer 1

Objective Caml - as functional as any language from ML family is, but as the name implies, also has a well-developed (and somewhat unique - the only fully structural one I'm aware of) OO system.

Answer 2

Common Lisp. The functional aspects are quite evident, and, on the other hand, CLOS is the mother of all object models.

Answer 3

Smalltalk. I'm sure many will disagree, but I think that the language that not only had first-class functions, but used them so heavily that even the most fundamental constructs (such as if/else and loops) were implemented as function calls taking function-type arguments, deserves the label "functional". Besides, you list Ruby, and most of what it has in FP department, it inherited from Smalltalk.

Answer 4

Nemerle is (unfortunately) not so widely known functional-OO hybrid designed to run on the .NET platform. What makes Nemerle interesting is its versatile macro system and powerful type inference.

Answer 5

O'Haskell, which is basically a Haskell with object-oriented features bolted on.

Answer 6

Racket is a functional language (a dialect of Scheme) with an class system. The class system supports both overridable methods (like Java, C#) and augmentable methods (the superclass's method gets control first; it decides if/when to call the subclass's method and what to do with the result). The class system also supports higher-order contracts.

Actually, there are many object systems for Lisps and Schemes. CLOS for Common Lisp is probably the most famous and influential.