Re: Why both "with" and "use"?

[Matthew Heaney <matthew_heaney@acm.org>]

"Pat Rogers" <progers@NOclasswideSPAM.com> writes:

> A package serves more of a central purpose in Ada 95, especially when
> it exports a tagged type declaration.
> 
> The big difference (or, at least one difference) between Java packages
> and Ada packages is that the combination of an Ada package and a
> private type defines an Abstract Data Type.

I wouldn't quite phrase it that way.  With respect to the declaration of
a type (and I mean _any_ kind of type, not just ADTs), the package in
which the type is declared serves to demarcate, among all the operations
in the universe that can take objects of that type as a parameter or
return value, those operations that are "primitive" for the type.

Perhaps I am being pedantic, but I don't regard a package as part of a
type.  I regard the type as its name, values, and (primitive)
operations.  The package is just syntactic overhead necessary to
identify the primitive operations, but the package itself is not part of
the type.

When they give me a bag at the supermarket to hold my groceries, it's the
groceries that I am interested in, not the bag.  If I were to make a
list of the things I picked up at the store, I probably wouldn't include
the bag in that list.