Steven D'Aprano wrote:
I'm asking what *problem* you are trying to solve with mutable numbers, where immutable numbers are not satisfactory. The only answer I can imagine is that you're worried about the overhead of creating new integer objects instead of just flipping a few bits in an existing integer variable.
Of course, *because ints are immutable*, an implementation can avoid the overhead of object creation for common cases by creating an array of small integers.
CPython currently does this for -10 (or -5?) to about 256 or 257. I would not be surprised if this coevers at least 80% of int.__new__ requests.
tjr -- http://mail.python.org/mailman/listinfo/python-list
