null and type safety

[Jarrett Billingsley]

On Tue, Nov 4, 2008 at 5:31 PM, Walter Bright
<newshound1 at digitalmars.com> wrote:
>> Don't you think that eliminating something that's
>> always a bug at compile time is a worthwhile investment?
>
> Not always. There's a commensurate increase in complexity that may not make
> it worth while.

Have you looked at Delight at all?  I wouldn't call the impact of
nullable types on D "commensurate."  It's probably far less than
const, invariant, pure, and escape analysis.

> My focus is on eliminating bugs that cannot be reliably detected even at run
> time. This will be a big win for D.

Can you expand upon this a bit?  What exactly are some bugs that can't
be reliably detected at runtime other than memory corruption?