Null references (oh no, not again!)

[Walter Bright]

Georg Wrede wrote:
> Cool! In the old days both jobs were filled with glamour.

So true. When my dad joined the Army Air Corps, one of the big reasons 
he wanted to be a pilot, instead of one of the other crew positions, is 
the pilots got the pick of the girls.

> http://www.airliners.net/search/photo.search?regsearch=OH-LCH&distinct_entry=true 

My dad flew gooney birds too.


> Dad used to give a hard time to others who didn't aspire to become 
> Superior Pilots. Sometimes, during pre-takeoff checks (one reads the 
> list aloud, ticking done entries, and another does the actual checking), 
> he used to switch to gibberish when reading an item. If the other guy 
> didn't notice, he gave hell for it. It was all about Respect for 
> regulations, Focus, and due Diligence. Not all young pilots understood 
> that *every single word* in air regulations, is the result of someone 
> already dead.

Yup. My dad has endless stories about overconfident pilots skipping 
something on the checklist and dying. It's becoming increasingly clear 
that the recent Turkish Airlines crash was because the pilots were 
asleep at the switch - they didn't even look out the window during 
landing approach.


> Checklists are an underutilised resource in software development. There 
> ought to be checklists "on paper" for pre-release checks for the staff, 
> for example. Also, since computers are good at mundane and repetitive 
> tasks, simple shell scripts that go through systems checking things 
> would be economical.
> 
> Contract Programming can be viewed as checklists on the micro level. 
> When you call a function, it goes through a list of things to check 
> before actually doing its job.

It's interesting that a lot of my experience at a seemingly unrelated 
discipline at Boeing has found its way into D's language design!