From: Robert Dober Date: 2010-04-18T00:42:00+09:00 Subject: Re: Formal methods On Sat, Apr 17, 2010 at 12:08 AM, Bernhard Brodowsky > It is most certainly true, that it is extremely difficult, but one has > to be ambitious some times. And actually, my formal methods professor > told me that it was difficult, but not impossible, but it depends which > properties I wanted to prove. Things like that I never call a method on > "nil" could be possible to prove according to him, so I just want to > give it a try. Unless you impose severe restrictions on your program you just need to implement a Ruby Interpreter. Even forbidding *eval does not suffice, you would need to forbid define_method too and I am probably forgetting something. Apart from these you need a Regexp interpreter etc,etc. The question is, what do you want to prove (pun intended), message flow, properties of closure, exception handling? Cheers Robert -- The best way to predict the future is to invent it. -- Alan Kay