[Python-Dev] PyObject_RichCompareBool identity shortcut (original) (raw)

Alexander Belopolsky alexander.belopolsky at gmail.com
Wed Apr 27 17:43:49 CEST 2011

On Wed, Apr 27, 2011 at 10:53 AM, Guido van Rossum <guido at python.org> wrote: ..

Maybe we should just call off the odd NaN comparison behavior?

+1

There was a long thread on this topic last year:

http://mail.python.org/pipermail/python-dev/2010-March/098832.html

I was trying to find a rationale for non-reflexivity of equality in IEEE and although it is often mentioned that this property simplifies some numerical algorithms, I am yet to find an important algorithm that would benefit from it. I also believe that long history of suboptimal hardware implementations of nan arithmetics has stifled the development of practical applications.

High performance applications that rely on non-reflexivity will still have an option of using ctypes.c_float type or NumPy.

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