Developing a plan for D2.0: Getting everything on the table

[Sergey Gromov]

Mon, 27 Jul 2009 07:59:40 -0500, Andrei Alexandrescu wrote:

>> Is it appropriate to define multiple classes, structs, templates, etc 
>> within a single module? What considerations should inform the decision 
>> regarding the placement of module boundaries?
> 
> I think it's appropriate because many pieces of functionality come as a 
> bundle. The rule of thumb is, module provides the functionality, and 
> it's up to the designer to decide what that entails.

That's the problem.  On one hand, it's desirable to see a module as a
functionality bundle.  On the other hand, module is the smallest
available unit of encapsulation.  That is, if you have a class and
change its private implementation, this may affect *anything* in the
same module.  Hence Tango's hundreds of modules in dozens of packages, I
think.

It also adds to the problem that most people familiar with OO paradigm
consider classes to be such encapsulation units.  Surprizes are
inevitable.