But could that kind of type system be considered similar to the usual Java-like little-flexible static typing? I think I would prefer a static vs dynamic implemented as Java vs Python (since those are usually the subjects on every one of these discussions)
ALthough the name is confusing type classes are very much like interfaces in Java: you define a set of operations that you want and then instantiate concrete types to that interface.
The major differences between type classes and interfaces are:
* In Java interfaces the interfaced type is restricted to the first argument (the this). In Haskell interfaces the interfaced type can also appear on return values and arguments.
* In Java you need to decide what interfaces to implement when you create your class. Haskell allows interfaces to be implemented for previously existing types.
* Java allows for subtyping. You can turn a monomorphic program into a polymorphic one just by creating subclasses while in Haskell you would need to rewrite your code to be explicitly polymorphic.
