RG <rnospa...@flownet.com> writes: > Yes, I know I could have used lint. But that misses the point. For any > static analyzer, because of the halting problem, I can construct a > program that either contains an error that the analyzer will not catch, > or for which the analyzer will produce a false positive.
Can you describe any plausible real-world programs where the effort of complicated static is justified, and for which the halting problem gets in the way of analysis? By "real world", I meanI wouldn't consider searching for counterexamples to the Collatz conjecture to qualify as sufficiently real-world and sufficiently complex for fancy static analysis. And even if it did, the static analyzer could deliver a partial result, like "this function either returns a counterexample to the Collatz conjecture or else it doesn't return". D. Turner wrote a famous paper arguing something like the above, saying basically that Turing completeness of programming languages is overrated: http://www.jucs.org/jucs_10_7/total_functional_programming The main example of a sensible program that can't be written in a non-complete language is an interpreter for a Turing-complete language. But presumably a high-assurance application should never contain such a thing, since the interpreted programs themselves then wouldn't have static assurance. -- http://mail.python.org/mailman/listinfo/python-list
