[Python-ideas] Floating point contexts in Python core

[Mark Adam]

On Fri, Oct 12, 2012 at 5:54 PM, Mark Adam <dreamingforward at gmail.com> wrote:
> On Thu, Oct 11, 2012 at 8:03 PM, Steven D'Aprano <steve at pearwood.info> wrote:
>>>> I would gladly give up a small amount of speed for better control
>>>> over floats, such as whether 1/0.0 raised an exception or
>>>> returned infinity.
>>>
>>> Umm, you would be giving up a *lot* of speed.  Native floating point
>>> happens right in the processor, so if you want special behavior, you'd
>>> have to take the floating point out of hardware and into "user space".
>>
>> Even in user-space, you're not giving up that much speed in practical
>> terms, at least not for my needs. The new decimal module in Python 3.3 is
>> less than a factor of 10 times slower than Python's floats, which makes it
>> pretty much instantaneous to my mind :)
>
> Hmm, well, if it's only that much slower, then we should implement
> Rationals and get rid of the issue altogether.

Now that I think of it, this issue has a strange whiff of the argument
wherefrom came the "from __future__" directive and the split that
happened between the vpython folks who needed the direct support of
float division (rendering 3-d graphics for an interpreted environment)
and the regular python crowd.   Anyone else remember that?

mark