[Python-ideas] A macro for easier rich comparisons

[M.-A. Lemburg]

On 18.03.2015 11:53, Petr Viktorin wrote:
> ...
> I propose adding a public macro to ease this. My version takes two C-orderable values and the
> operation, similar to richcmpfunc:
> 
> #define Py_RICHCOMPARE(val1, val2, op) ( \
>     ((op) == Py_EQ) ? PyBool_FromLong((val1) == (val2)) : \
>     ((op) == Py_NE) ? PyBool_FromLong((val1) != (val2)) : \
>     ((op) == Py_LT) ? PyBool_FromLong((val1) < (val2)) : \
>     ((op) == Py_GT) ? PyBool_FromLong((val1) > (val2)) : \
>     ((op) == Py_LE) ? PyBool_FromLong((val1) <= (val2)) : \
>     ((op) == Py_GE) ? PyBool_FromLong((val1) >= (val2)) : \
>     (Py_INCREF(Py_NotImplemented), Py_NotImplemented))
> 
> (As for the behavior for unknown op: for most cases the best thing to do is setting an error and
> returning NULL, but that doesn't fit into a macro. A surprising number of richcmpfunc's in CPython
> either return NULL without error (e.g. tupleobject), or fall through and return True/False
> arbitrarily (as in bytearrayobject). Datetime does an assert.
> I think Py_NotImplemented is a good value to return)
> ...
> Is this a PEP-worthy idea?

This is a great idea, no need for a PEP :-) Please submit the patch on
the bug tracker and also include a patch for the C API documentation.

Thanks,
-- 
Marc-Andre Lemburg
eGenix.com

Professional Python Services directly from the Source  (#1, Mar 18 2015)
>>> Python Projects, Coaching and Consulting ...  http://www.egenix.com/
>>> mxODBC Plone/Zope Database Adapter ...       http://zope.egenix.com/
>>> mxODBC, mxDateTime, mxTextTools ...        http://python.egenix.com/
________________________________________________________________________
2015-03-12: Released mxODBC 3.3.2 ...             http://egenix.com/go71

::::: Try our mxODBC.Connect Python Database Interface for free ! ::::::

   eGenix.com Software, Skills and Services GmbH  Pastor-Loeh-Str.48
    D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg
           Registered at Amtsgericht Duesseldorf: HRB 46611
               http://www.egenix.com/company/contact/