Why don't other programming languages have ranges?

[Walter Bright]

Jim Balter wrote:
> You're being religious about this and arguing against a strawman. While 
> all parts are unreliable, they aren't *equally* unreliable.

They don't have to have equal reliability in order for redundancy to be very 
effective.


> Unit tests, 
> contract programming, memory safe access, and other reliability 
> techniques, *including correctness proofs*, all increase reliability.

True, but the problem is when one is seduced by that into thinking that 
redundancy is not necessary.


> On the flip side, you can't guarantee reliability with simplistic rules 
> like "no continuing after an exception".

Of course, but you can guarantee unreliability by thinking one can continue 
after an exception thrown by a programming error. (In engineering, one can never 
"guarantee" reliability anyway. What one does is set a maximum failure rate, and 
prove a design is more reliable than that.)

Blindly applying rules without using one's brain is bad, and ignoring rules 
without thoroughly understanding their rationale is equally bad.


> Numerous (relatively) reliable systems have demonstrated that religion to be a myth as well.

If there's an interesting example here, please tell me about it!

As for the religion aspect, please consider that I get this from my experience 
with how airliners are designed. I think there can be little doubt that these 
techniques (religion) are extremely effective in producing incredibly reliable 
and safe airline travel.