> C# and Java are badly designed, D may do better. In my opinion a better
> solution to this problem is to:
> 1) Introduce non-nullable pointers/references, to denote them I have proposed
> a trailing @.
> 2) Require explicit tests every time a nullable pointers/references is about
> to be dereferenced (and then after this test in the else branch the reference
> type "becomes" a non-nullable one. This is an application of the idea of
> "TypeState", used by the Mozilla Rust language. The type doesn't actually
> change, it's just its state that changes...).
>
> This way you don't need (most) implicit null checks.
>
> Bye,
> bearophile
>
I think I'm tracking with you, bearophile and it sounds like a good
solution. You are suggesting a compile-time null check, correct?
However, instead of non-nullable references I would argue that all
references be non-nullable by default (like Vala does). For example:
-------------
char[]@ foo()
{
if (some condition)
return "yada";
else
return null; //causes compile error if you remove the @ symbol
above
}
int main(char[][] args)
{
char[]@ s = foo(); //causes compile error if you remove @ symbol
if (something)
{
assert(s != null);
printf(s); //causes compile error if you remove above assertion
}
else if (s == null)
return 1;
printf(s); //causes compile error if you remove above assertion or
else-if condition
return 0;
}
-------------
Vala has something kind of like this with their trailing '?' syntax
although the feature is not as thorough as the above. (See
http://live.gnome.org/Vala/Tutorial#Methods)
