Null references redux

[Jeremie Pelletier]

Ary Borenszweig wrote:
> Jeremie Pelletier wrote:
>> Ary Borenszweig wrote:
>>> Walter Bright wrote:
>>>> Denis Koroskin wrote:
>>>>  > On Sat, 26 Sep 2009 22:30:58 +0400, Walter Bright
>>>>  > <newshound1 at digitalmars.com> wrote:
>>>>  >> D has borrowed ideas from many different languages. The trick is to
>>>>  >> take the good stuff and avoid their mistakes <g>.
>>>>  >
>>>>  > How about this one:
>>>>  > 
>>>> http://sadekdrobi.com/2008/12/22/null-references-the-billion-dollar-mistake/ 
>>>>
>>>>  >
>>>>  >
>>>>  > :)
>>>>
>>>> I think he's wrong.
>>>
>>> Please, please, please, do some fun little project in Java or C# and 
>>> drop the idea of initializing variables whenever you declare them. 
>>> Just leave them like this:
>>>
>>> int i;
>>>
>>> and then later initialize them when you need them, for example 
>>> different values depending on some conditions. Then you'll realize 
>>> how powerful is having the compiler stop variables that are not 
>>> initialized *in the context of a function, not necessarily in the 
>>> same line of their declaration*. It's always a win: you get a compile 
>>> time error, you don't have to wait to get an error at runtime.
>>>
>>> Until you do that, you won't understand what most people are 
>>> answering to you.
>>>
>>> But I know what you'll answer. You'll say "what about pointers?", 
>>> "what about ref parameters?", "what about out parameters?", and then 
>>> someone will say to you "C# has them", etc, etc.
>>>
>>> No point disussing non-null variables without also having the 
>>> compiler stop uninitialized variables.
>>
>> All null values are uninitialized, but not all initializers are null, 
>> especially the void initializer.
> 
> I don't see your point here. "new Object()" is not a null intiializer 
> nor "1"... so?

Object o = void;

>  You can't always rely on initializers
>> in your algorithms, you can always rely on null.
> 
> Yes, I can always rely on initializers in my algorithm. I can, if the 
> compiler lets me safely initialize them whenever I want, not necessarily 
> in the line I declare them.
> 
> Just out of curiosity: have you ever programmed in Java or C#?

Nope, never got interested in these to tell the truth. I only did C, 
C++, D and x86 assembly in systems programming, I have quite a 
background in PHP and JavaScript also.

I played with a lot of languages, but those are the ones I use on a 
daily basis. I would like to get into Python or Ruby someday, I only 
hear good things about these two. I know LUA has less overhead than 
Python, but it's more of a support language to implement easy scripting 
over C than a standalone language, I already have my LUA bindings for D 
ready to do just that.

I like extremes :)