On 4/28/11 12:00 PM, Alexander Belopolsky wrote:
On Thu, Apr 28, 2011 at 12:46 PM, Robert Kern<robert.kern@gmail.com> wrote: ..
Python uses the< operator for sorting, not a comparison function, so it's current behavior is perfectly in line with the IEEE-754 spec.
No, it is not. As I explained in the previous post, IEEE-754 prescribes different behavior for<,>,<=, and>= operations and != and ==. The former signal INVALID exception while the later don't. Python does not make this distinction.
But it also states that such signals should *not* trap by default. The only thing I can really fault Python for, compliance-wise, is that it will hide the FPE from being handled in user code because of the PyFPE_START_PROTECT/PyFPE_END_PROTECT macros that surround the actual C operation. The only way to get the FPE to handle it is to build and install fpectl, which is officially discouraged. -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco