Re: [Haskell-cafe] Module visibility of data type constructors

Slavomir,

module Foo (Bar) where data Bar = Bar

In ghc this allows me to use Bar, the type constructor, in another module, although it shouldn't be visible outside Foo. On the other hand, if I change Bar's definition as:

data Bar = Baz

Baz isn't visible outside Foo.

On terminology: in data T = D T is called a type constructor and is called a *data* constructor. Cheers, Stefan