On Jan 2, 2013, at 4:24 PM, Никитин Лев
Well, we can say "concepts" in place of "theory". And I'm comparing Eiffel with other OOP lang, not with some langs based on a solid math theory (lambda calcules for FP langs, for example). ok?
I agree that there are certain concepts, or ideas, that Eiffel is built on. If that is what you meant, sure, I have no problem with that. Of course, there are plenty of languages based on some specific ideas. For example, take the following concepts: 1) it's better to do something instead of failing, even if it doesn't make any sense; 2) global is better then local; 3) for every feature that can be implemented in two ways there should be a switch that the user can set as xe wishes. Implement these as fully as possible — and you'll get PHP. So, somehow I doubt that being based on some set of ideas is a very strong selling point.
BTW. Why you think that Eiffel type system is unsafe?
Well, if I remember correctly, if you call some method of a certain object, and this call compiles, you can't be certain that this object actually has this method. Could be that this object belongs to some subclass which removes this method.