Sealed classes - would you want them in D?

[KingJoffrey]

On Saturday, 12 May 2018 at 00:39:29 UTC, Mike Parker wrote:
>
> Again, they're in the same module. From an encapsulation stand 
> point, what does it matter that private members are within or 
> without any specific set of curly braces? It only matters if 
> you want to adhere to a purely conceptual view of 
> encapsulation. From a practical view, it matters not one whit.
>
>>

It matters, in the same sense, that it matters if you have a 
module, full of functions (which are encapsulated units of code), 
but your module has a whole bunch of goto statements (not 
necessarily within a function). Now...you've essentially no idea 
now which functions are truly encapsulated, and which aren't. You 
now have to take into view, 'the whole module' - which goes 
against the very principle of problem solving by breaking down 
the problem into smaller pieces.

I have looked a D source code modules. I challenge anyone to get 
there head around whole modules.

In a similar vain to gotos, having classes (which are 
traditionally meant to be encapsulated units of code) in a 
module, but also having anything in the module (outside of the 
class[es]), having the capacity to do whatever it wants to the 
private parts of the class.

We're back in goto land!