Le 10/02/2013 21:53, Rob Weir a écrit :
The error in your thinking is to persist in arguing that there is only one correct answer. That is false. I can point to mathematical authorities of great reputation to argue for any of three answers. The question is whether we change from the correct answer we give in AOO 3.4.1 and before to a different correct answer, and in doing so break compatibility.
The problem is to give the answer that is the most useful for the user. Shall we tell him 1 or tell him that there is an error because he came upon a corner case? Of course I see your point. But is it the best behavior to hide a potential issue to the user, letting him think that everything is OK?
Let me show you how lame this argument is. What is sqrt(4)? 2, right? Well, that is one convention. -2 is also a valid answer. Would you be OK if we changed the code to return -2? What about an error message because it is ambiguous? Of course, not, because we adopt the convention to return the positive root only.
But there is no uncertainty here. Like angles and trigonometric functions, there are 2 possibilities. There are no corner case here. It is assumed that the user knows what he's doing. I've no problem with conventions, as long as they give the best answer to the user. What about giving 1 or 0 to 0/0? That would be very comfortable! But giving an error is the best way because it warns the user that there is a problem (that would get unnoticed else and lead to definitively wrong results). We all have experienced this #DIV/0! error and we are happy with it because we can investigate and find out that there was a mistake somewhere. Same for the 0^0 issue. Giving an error could make the user aware that there is a mistake in his calculation. Giving a result can hide such mistakes. Hagar
