> But in the worst case scenario, you'll end up with extremely unmaintainable code. Actually, isn't it far worse than that? Say you're stopped at a function ca

> But in the worst case scenario, you'll end up with extremely unmaintainable code. Actually, isn't it far worse than that? Say you're stopped at a function call, you call it, and it does the wrong thing. You edit a variable that's passed as an argument to the function and call it again. Now it does the right thing. Great! You fixed the bug, right? Except that you don't actually know that your program can actually ever end up in that state naturally. Where did that variable originally come from? Was it entered by the user? Was it read from a file? Was it from a table? If so, does the table contain the modified value? This seems like a recipe for problems to me. I'm sure it's fine in simple cases where you're just changing the value of a constant or something, but it seems really likely to lead to incorrect reasoning about the code while you're working with it in any but the simplest of cases. Am I blowing this out of proportion?