Export lists in modules

[Malcolm Wallace]

"Jared Updike" <jupdike at gmail.com> wrote:

> > I am not sure if this has been mentioned before, but something I
> > would really find useful is the ability to tell Haskell to export
> > everything in a function except for some named functions.
> 
> No one has responded so ...

I believe some people (perhaps on another list) have been advocating the
addition of Java-style public/private modifiers on function definitions,
to indicate whether they are exported or not.  (A truly horrible idea in
my opinion!)

> > module Module hiding ( list, of, things, not, to, export ) where
> > ....

I quite like this for its minimal syntactic overhead, and backward
compatibility.  There is a slight worry that it would be too easy to
overlook the "hiding" keyword when reading a module, leading to
confusion.

There is also the issue that we might adopt the proposal to allow (and
perhaps eventually, to require) type signatures on export lists.  If so,
then it would be kind of ridiculous to have interface signatures only
for the things you are /not/ exporting!

Regards,
    Malcolm