>-----Original Message----- >From: Pascal J. Bourguignon >Sent: Monday, December 31, 2012 4:22 PM >To: Fundamentals of New Computing >Subject: Re: [fonc] Linus Chews Up Kernel Maintainer For Introducing Userspace >Bug - Slashdot > >"Carl Gundel" <ca...@psychesystems.com> writes: > >> “If there are contradictions in the design, the program shouldn't >> compile.” >> >> >> >> How can a compiler know how to make sense of domain specific >> contradictions? I can only imagine the challenges we would face if >> compilers operated in this way. > >Contradictions are often not really contradictions.
I was referring to the contradictions that really are contradictions. ;-) >It's a question of representation, that is, of mapping of the "domain", >to some other "domain", usually a formal system. Yet another dimension in which we can make a mistake? Would this be another kind of unit test? Unit tests can be useful, but they have to be correct and there is a cost to maintaining them. >Now we know that a given formal system cannot be at the same time complete >and consistent, but nothing prevents an automatic system to work with an >incomplete >system or an inconsistent system (or even a system that's both incomplete and >inconsistent). > >The only thing, is that sometimes you may reach conclusions such as 1=2, but >if you >expect them, you can deal with them. We do everyday. > >Notably, by modifying the mapping between the domain and the formal >system: for different parts of the domain, you can use different formal >systems, or >avoid some axioms or theorems leading to a contradiction, to find some usable >conclusion. Are you just talking about a system which will run real time uber lint checks that you can refer to while writing code? >Daily, we use formal rules, that are valid just in some context. The >conclusions >we reach can easily be invalidated, if the context is wrong >for the application of those rules. If we tried to take into account >all the possible rules, we'd get soon enough inconsistencies. But by >restricting >the mapping of the domain to some contextual rules, we can read usable >conclusions >(most of the time). When the conclusion doesn't match the domain, we may ask >where the error is, and often it's just the context that was wrong, not the >rules. Okay, but if I have to waste my time struggling through the mostly usable conclusions to figure out which ones are usable, and whether or not I actually care about the conclusion, then the value of such a system is debatable. >We will have to embrace Artifical Intelligence, even in compilers, eventually. Yeah, let me know when it is finally invented so I can give it a big hug. -Carl _______________________________________________ fonc mailing list fonc@vpri.org http://vpri.org/mailman/listinfo/fonc
