#17727: Remove redundant parent_c() functions
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Reporter: jdemeyer | Owner:
Type: enhancement | Status: needs_review
Priority: major | Milestone: sage-6.5
Component: coercion | Resolution:
Keywords: | Merged in:
Authors: Jeroen Demeyer | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Commit:
u/jdemeyer/ticket/17727 | 3547ea8990d2c2f76001df02dac213956c515e07
Dependencies: | Stopgaps:
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Comment (by vdelecroix):
Replying to [comment:7 mmezzarobba]:
> Replying to [comment:6 vdelecroix]:
> > According to Python documentation
> > {{{
> > int PyNumber_Check(PyObject *o)
> > Returns 1 if the object o provides numeric protocols,
> > and false otherwise. This function always succeeds.
> > }}}
> > So even sage integers, floating points numbers and many others will
answer true to that (I checked). And from the specification I do not see
how such test can be fast.
>
> I don't understand your comment. As far as I understand `PyNumber_Check`
should amount to check if the corresponding `PyTypeObject`'s
`tp_as_number` is non-`NULL`, and that should indeed be pretty fast.
You are definitely right
{{{
int
PyNumber_Check(PyObject *o)
{
return o && o->ob_type->tp_as_number &&
(o->ob_type->tp_as_number->nb_int ||
o->ob_type->tp_as_number->nb_float);
}
}}}
... (but it answers `True` on much more instances than only int/float) ...
Most important is the other question: why should we return `x.parent()` if
it is not an element?
Vincent
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Ticket URL: <http://trac.sagemath.org/ticket/17727#comment:8>
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