make PolynomialQuotientRing_generic inherit from QuotientRing_generic

[yyyyx4]

This will make it easier to write code that works uniformly for all kinds of quotient rings.

(Example: Polynomial quotient rings currently do not have the .cover() and .defining_ideal() methods, which are very useful when writing generic quotient-ring code.)

Component: algebra

Author: Lorenz Panny

Branch/Commit: b56ebf9

Reviewer: Marc Mezzarobba

Issue created by migration from https://trac.sagemath.org/ticket/34463

[yyyyx4]

Commit: 0d42205

[yyyyx4]

Author: Lorenz Panny

[yyyyx4]

Branch: public/make_PolynomialQuotientRing_inherit_from_QuotientRing

[roed314]

comment:2

There seems to be a test failure

File "sage/schemes/elliptic_curves/hom_velusqrt.py", line 829, in sage.schemes.elliptic_curves.hom_velusqrt.EllipticCurveHom_velusqrt
Failed example:
    any(map(check, psi.codomain().isomorphisms(phi.codomain())))
Expected:
    True
Got:
    False

and some linting failures

sage/schemes/elliptic_curves/hom_velusqrt.py:325:9: E306 expected 1 blank line before a nested definition, found 0
sage/schemes/elliptic_curves/hom_velusqrt.py:327:9: E306 expected 1 blank line before a nested definition, found 0
sage/functions/special.py:867:12: W605 invalid escape sequence '\p'
sage/functions/special.py:867:19: W605 invalid escape sequence '\p'
sage/algebras/clifford_algebra.py:2987:21: E721 do not compare types, use 'isinstance()'

The linting problems don't look like they're due to this ticket, but I'm not sure about the test failure.

[yyyyx4]

comment:3

Thanks for having a look. The test failure is #34467, and the linter errors should go away with #34466.

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

b56ebf9

Merge tag '9.7' into public/make_PolynomialQuotientRing_inherit_from_QuotientRing

[sagetrac-git]

Changed commit from 0d42205 to b56ebf9

[mezzarobba]

Reviewer: Marc Mezzarobba

[mezzarobba]

comment:5

I think is_Class functions that just perform a type test are considered obsolete, so I would write if not isinstance(x, PolynomialQuotientRing_generic) instead of calling is_PolynomialQuotientRing. Lgtm otherwise!

[vbraun]

Changed branch from public/make_PolynomialQuotientRing_inherit_from_QuotientRing to b56ebf9