Which D features to emphasize for academic review article

[Era Scarecrow]

On Saturday, 11 August 2012 at 04:33:38 UTC, Walter Bright wrote:
> It's too bad that ints don't have a NaN value, but 
> interestingly enough, valgrind does default initialize them to 
> some internal NaN, making it a most excellent bug detector.

  The compiler could always have flags specifying if variables 
were used, and if they are false they are as good as NaN. Only 
downside is a performance hit unless you Mark it as a release 
binary. It really comes down to if it's worth implementing or 
considered a big change (unless it's a flag you have to specially 
turn on)

example:

   int a;

   writeln(a++); //compile-time error, or throws an exception on 
at runtime (read access before being set)

internally translated as:
   int a;
   bool _is_a_used = false;

   if (!_a__is_a_used)
     throw new exception("a not initialized before use!");
     //passing to functions will throw the exception,
     //unless the signature is 'out'
   writeln(a);

   ++a;
   _a__is_a_used= true;


> Sadly, D has to map onto imperfect hardware :-(

  Not so much imperfect hardware, just the imperfect 'human' 
variable.

> We do have NaN values for chars (0xFF) and pointers (the 
> villified 'null'). Think how many bugs the latter has exposed, 
> and then think of all the floating point code with no such 
> obvious indicator of bad initialization.