Why don't other programming languages have ranges?

[Jim Balter]

"Don" <nospam at nospam.com> wrote in message 
news:i2rk4b$2jet$1 at digitalmars.com...
> Jim Balter wrote:
>>
>> "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.
>
> I have to disagree with that. "Correctness proofs" are based on a total 
> fallacy. Attempting to proving that a program is correct (on a real 
> machine, as opposed to a theoretical one) is utterly ridiculous.
> I'm genuinely astonished that such an absurd idea ever had any traction.

I've also heard from people genuinely astonished that such an absurd idea as 
that humans evolved from worms ever had any traction. I'm equally impressed 
by both. For a more rational discussion, see 
http://c2.com/cgi/wiki?ProofOfCorrectness