assert semantic change proposal

[David Bregman via Digitalmars-d]

On Sunday, 3 August 2014 at 22:57:24 UTC, Ola Fosheim Grøstad 
wrote:
> On Sunday, 3 August 2014 at 22:18:29 UTC, John Carter wrote:
>> My view, which I think corresponds with Walter's and Betrand 
>> Meyer's, is that asserts define what correct behaviour is.
>
> No. The propositions describe what the correct behaviour ought 
> to be. The asserts request them to be proved.
>
>> And the sooner you know that, preferably at compile time, the 
>> better.
>
> And to do that you need a theorem prover capable of solving 
> NP-Hard problems. So you need a veeeery intelligent programmer 
> to write provably correct code without any special tools.
>
>> Continuing past such an assert inevitably results in 
>> defective, possibly catastrophic, possibly flaky behaviour.
>
> And Walter thinks it would a great idea to make that 
> catastrophic behaviour occur with a much greater probability 
> and also every time you execute your program, undetected, not 
> only in the select few cases where slight overlap in conditions 
> were detected.
>
> So basically if your program contains an assert that states 
> that the program should stop working in 30 years from now, it 
> is a good idea to make it fail randomly right away. That's the 
> view that Andrei, Don and Walter has expressed very explicitly.
>
> People who thinks this is a great idea defies reason. They only 
> learn from failure.
>
> You have to realize that a deduction engine cannot tolerate a 
> single contradiction in axioms. If there is a single 
> contradiction it can basically deduce anything, possibly 
> undetected.
>
> Turning asserts in program+libaries into globally available 
> axioms is insane.

John proposes a separate function, so I think you two are in 
agreement on what really matters. Let's try to avoid going too 
deep into tangents, unlike the other threads - it didn't work 
well last time.