Re: Trivial Ada question

["Robert I. Eachus" <rieachus@attbi.com>]

Grein, Christoph wrote:


> This was a joke, wasn't it? Is this really better than a simle and innocent and 
> nearby goto? A one-time 'loop' enclosing another work loop...
...
> I have to confess that I have not needed a goto in so many years, but the goto 
> solution is one of the simplest solutions of all those presented.


I totally agree.  However, there is a "reasonable" nested loop version...

   INCREMENT:
     loop
       for I in A'Range loop
         exit INCREMENT when condition (A (I));
       end loop;
       N := N + 1;
       exit INCREMENT;
     end loop;

Again the compiler has a chance to generate the correct simple code. 
But we still haven't done anything about the fact that the inner loop 
has two exits that need to be tested.  (The outer loop has a single exit 
and doesn't add any real complexity to the program flow.)

Which is why this discussion sort of bothers me.  The underlying 
complexity of the algorithm can be hidden, but who are you hiding it 
from?  It had better not be the test team.  And that is why I like the 
goto here.  It screams to the testers (and other readers) that the water 
  is deep here.  You have to insert a mental bookmark and read the two 
paths separately.

In fact, the I would probably stick in a comment:
  -- This loop must have two exits.

It is the "must have" that is key, not how it is implemented.