Why don't other programming languages have ranges?

[Jim Balter]

"Walter Bright" <newshound2 at digitalmars.com> wrote in message 
news:i2nkto$8ug$1 at digitalmars.com...
> bearophile wrote:
>> You have to think about proofs as another (costly) tool to avoid 
>> bugs/bangs,
>> but not as the ultimate and only tool you have to use (I think dsimcha 
>> was
>> trying to say that there are more costly-effective tools. This can be 
>> true,
>> but you can't be sure that is right in general).
>
> I want to re-emphasize the point that keeps getting missed.
>
> Building reliable systems is not about trying to make components that 
> cannot fail. It is about building a system that can TOLERATE failure of 
> any of its components.
>
> It's how you build safe systems from UNRELIABLE parts. And all parts are 
> unreliable. All of them. Really. All of them.

You're being religious about this and arguing against a strawman. While all 
parts are unreliable, they aren't *equally* unreliable. Unit tests, contract 
programming, memory safe access, and other reliability techniques, 
*including correctness proofs*, all increase reliability.

On the flip side, you can't guarantee reliability with simplistic rules like 
"no continuing after an exception". Numerous (relatively) reliable systems 
have demonstrated that religion to be a myth as well.