On 5/19/13 1:35 PM, deadalnix wrote:
On Sunday, 19 May 2013 at 13:13:07 UTC, Andrei Alexandrescu wrote:
On 5/19/13 9:11 AM, deadalnix wrote:
It is both a race condition and a null problem.
No, it's just a race condition.
And having non nullable
type would have been a compile time error instead of days of debugging.
No, the race condition would have stayed.
That is ridiculous. non nullable would have made the bug non existent,
and even without race condition the problem would exists. a reference is
null, it container shared, then set to something else. You can put
barriers all over the place to make that sequentially consistent that it
wouldn't change anything and the bug would still arise.
No, your argument is ridiculous. You make a yarn with precious little
detail that describes for everything everyone knows a textbook race
condition, essentially ask that you are taking by your word that
non-null would miraculously solve it, and, to add insult to injury, and
when we don't buy it, you put the burden of proof on us. This is quite a
trick, my hat is off to you.
You also never provided any convincing solution to the safety hole.
What's the safety hole? Objects of large static size?
We
can't even add check only on some edges cases as D also have values
types. The only solution we are left with that is really safe is to null
check every dereference or give up on @safe.
How about using NonNull. We won't change the language at this point to
make non-nullable references by default. Even you acknowledged that
that's not practical. So now you contradict your own affirmation. What
exactly do you sustain, and what are you asking for?
I encourage you to look at this :
http://www.infoq.com/presentations/Null-References-The-Billion-Dollar-Mistake-Tony-Hoare
I read it. I don't buy it. Yeah, it's a point, but it's largely
exaggerated for dramatic purposes.
Most new languages removed nullable by default, or limited its uses
(scala for instance, allow for null for limited scope).
So what do you realistically think we should do, seeing that we're
aiming at stability?
I once again want to get attention on the fact that GC change everything
in regard to reference, and that the C++ situation is a bad example.
I don't understand this.
Andrei
