[quickthrower]

In Haskell everything is public by default unless you specify exports for the module.

[aisofteng]

But it also has a statically checked type system.

[quickthrower]

I think if done in Haskell how good or bad it is depends on the chosen abstraction for effects not Haskell itself.

Haskell is a good basis but the developers need to make the API fool proof. E.g. expose limited effects rather than a big fat "IO" type.