Does Haskell support object oriented programming

Question

Does it support concepts like separation of declaration and implementation (interfaces and classes in Java)?

How about restricting access (like access modifiers in J

Answer 1

I just discovered sth by accident, see https://github.com/complyue/ooh for a runnable program with full machinery (full code is still extremely short though).

I never imagined OO stylish program can be written in Haskel in such a way so straight forward!

Constructing object:

!o <- classC $^ (777, "hahah")

Calling direct methods:

  cx0 <- o $. getNumC $ ()
  o $. setNumC $ 888

Calling base methods:

  bx0 <- (o $.. cast'C'as'B) getNumB ()
  (o $.. cast'C'as'B) setNumB 999

Method arguments have to be uncurried as prototyped here, I suppose it's the preferable flavor when writing OO style code though.

While the object class definition appears verbose as hand-crafted for now, I believe Template Haskell has much to offer for better syntax sugar.