Hi Travis,
No, these routines are about the python types. They get used as `type(x) is
int` and `type(x) is long`. They are used in a different namespace from
`cdef int x` and `cdef long x` and cdef long long x` (well, the `x` is in
the cython object namespace. The C-types don't make it into the cython
object namespace. They are in a C type namespace).
The cython test routine above confirms that the objects `int` and `long`
(not the cdef type names!) are indeed the same object in cython
The code below confirms they are the python `int` type object:
sage: cython("""
....: def test(x):
....: return (x is long, x is int)
....: """)
sage: test(int)
(True, True)
On Sunday 25 February 2024 at 01:48:09 UTC-8 Travis Scrimshaw wrote:
> Sorry for the delayed response.
>
> If the C compiler can't tell the difference between an int and a long,
> then that suggests that there is still a difference. I am not sure that
> Cython has any specification that these are different. My understanding is
> Cython treats these as C types. Can we be certain that an int that is not a
> long will not find its way in? Could it also depend on someone's version of
> C/Python?
>
> Best,
> Travis
>
>
> On Thursday, February 22, 2024 at 2:52:25 PM UTC+9 Nils Bruin wrote:
>
>> I tried removal here:
>> https://github.com/sagemath/sage/pull/37420
>> and as expected it looks like it's working fine.
>>
>> On Wednesday 21 February 2024 at 19:06:50 UTC-8 Nils Bruin wrote:
>>
>>> well, I don't expect the C compiler to be smart enough to recognise the
>>> second is an "elif False:", so the "hurt" would be in additional code
>>> executed. Plus, having hidden "elif False:"s in a code base is a really bad
>>> code smell, so I think there is a penalty. What do you want to guard
>>> against? "int" and "long" becoming not synonyms in cython again? There will
>>> be probably other py2/3 relics in our code base. I think we should clean
>>> them up when encountered, unless we have a good reason not to.
>>>
>>> On Wednesday 21 February 2024 at 17:55:48 UTC-8 Travis Scrimshaw wrote:
>>>
>>>> I think so, but it might not hurt to have it.
>>>>
>>>> Best,
>>>> Travis
>>>>
>>>> On Thursday, February 22, 2024 at 9:54:32 AM UTC+9 Nils Bruin wrote:
>>>>
>>>>> I noticed the following cython code
>>>>>
>>>>> if S is long:
>>>>> return sage.rings.integer.long_to_Z()
>>>>> elif S is int:
>>>>> return sage.rings.integer.int_to_Z()
>>>>>
>>>>>
>>>>> https://github.com/sagemath/sage/blob/30fecca1981087a88eb8db2cf05e18edbb50d16f/src/sage/rings/integer_ring.pyx#L589C1-L593C1
>>>>>
>>>>> However, in cython with python3 we now have:
>>>>>
>>>>> sage: cython("""
>>>>> ....: def tst():
>>>>> ....: return int is long
>>>>> ....: """)
>>>>> sage: tst()
>>>>> True
>>>>>
>>>>> so I think the `elif` can be deleted. Is that correct?
>>>>>
>>>>
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