> Without type annotations, refactorings are never safe
There is a difference between "I can prove this is safe" and "this is safe". You guys need to start figuring out the difference between theory and practice.
In practice, "this is safe" often transforms to "I thought this was safe" at the most inopportune moment.
> Patently false.
It's a mathematical fact.
Without type annotations, refactorings are never safe and need supervision from a human.
Did you notice that the "Refactoring Browser" calls itself just that, not "Automatic"?
Because it can't provide that guarantee. Even renaming a function is dangerous and can break a program when you don't have type annotations.
I have a lot of respect for Smalltalk and the pioneering work it accomplished, but the refactoring browser was just a powerful string replacement engine, nothing more. Which is not a knock on the engineers and scientists who invented it: it simply, mathematically, could not do more than that.