On Thu, 29 Mar 2007 00:57:03 -0700 [EMAIL PROTECTED] (Alex Martelli) wrote:
> Martin Manns <[EMAIL PROTECTED]> wrote: > > 2) Is there any inf type around with > > a + inf == inf > > inf > a (as long as a != inf) > > etc. > > that works with any other type? > > You mean something like: > > class inf(object): > def __radd__(self, other): return self > def __gt__(self, other): return self is not other > # etc > inf = inf() Actually, I meant something a bit more sophisticated: a=inf() b=inf() c=-inf() d=1e99999 e=numpy.float64(1e99999) f=gmpy.mpq(1,2) a > b OverflowError (AmbiguousValueError?) a == b OverflowError (AmbiguousValueError?) a + b inf (New inf instance) a + c OverflowError (AmbiguousValueError?) a + d a max(a,b) inf (New inf instance) max(a,c) a max(a,d) a max(a,b) == a OverflowError (AmbiguousValueError?) max(a,b) == b OverflowError (AmbiguousValueError?) max(a,b) > a OverflowError (AmbiguousValueError?) max(a,b) >= a True (if somehow possible) max(a,b) < a False (if somehow possible) a is b False a > c True a == -a False a == -c OverflowError (AmbiguousValueError?) a > d True a > e True c > f False The idea is a class that permits non-ambiguous comparisons but throws exceptions if ambiguous comparisons are made. Since I think that setting up such a class involves quite some effort (especially considering things such as a + a) I just wanted to know if something similar is already around. I am aware of the PEP 326 but I feel that it does not really address the problem. Martin -- http://mail.python.org/mailman/listinfo/python-list
