Empty VS null array?

[Shammah Chancellor]

On 2013-10-18 17:32:58 +0000, Jonathan M Davis said:

> On Friday, October 18, 2013 09:55:46 Andrei Alexandrescu wrote:
>> On 10/18/13 9:26 AM, Max Samukha wrote:
>>> *That's* bad API design. readln should be symmetrical to writeln, not
>>> write. And about preserving the exact representation of new lines,
>>> readln/writeln shouldn't preserve that, pure and simple.
>> 
>> Fair point. I just gave one possible alternative out of many. Thing is,
>> relying on client code to distinguish subtleties between empty and null
>> strings is fraught with dangers.
> 
> Yeah, but the primary reason that it's bad design is the fact that D tries to
> conflate null and empty instead of keeping them distinct (which is essentially
> the complaint that was made). Whether that's ultimately good or bad is up for
> debate, but the side effect is that relying on the difference between null and
> empty ends up being very bug-prone, whereas in other languages which don't
> conflate the two, it isn't problematic in the same way, and it's much more
> reasonable to have the API treat them differently.
> 
> - Jonathan M Davis

Null and the Empty Set are different entities.   A set containing 
exactly nothing, vs undefined.   However, null is not handled properly 
in D or any other systems language since it's simply a pointer with 
value = 0.  if (null == 0) is a true statement in C, C++, and D, but is 
not in fact true.  Null is neither equal to zero, nor not equal to zero.