repr(PolynomialRing(ZZ, 1, 'x')) is ambiguous

[mwhansen]

sage: type(PolynomialRing(ZZ, 1, 'x'))
<class 'sage.rings.polynomial.multi_polynomial_ring.MPolynomialRing_polydict_domain'>

sage: type(PolynomialRing(ZZ, 'x'))
<class 'sage.rings.polynomial.polynomial_ring.PolynomialRing_integral_domain'>

Component: basic arithmetic

Issue created by migration from https://trac.sagemath.org/ticket/764

[mwhansen]

comment:1

From William Stein:

Wait! This would an explicit intentional design choice, not a bug.
I think it should be possible to create ZZ['x'] but as a multivariate
polynomial ring instead of a univariate polynomial ring,
since there are certain things one can do with multivariate
polynomial rings that don't make sense with single variate rings.

Maybe I'm wrong, since things have been so well developed by now.
I would like some further discussion and input (esp. from Martin Albrecht)
on this before changing anything.

[mwhansen]

comment:2

sage: PolynomialRing(ZZ, 'x')
Univariate Polynomial Ring in x over Integer Ring
sage: PolynomialRing(ZZ, 1, 'x')
Polynomial Ring in x over Integer Ring

The second one is a bit ambiguous. How do people feel about changing
the reprs of multivariate polynomial rings so that the second one
would be 'Multivariate Polynomial Ring in x over Integer Ring'?

[mwhansen]

comment:3

Patches posted to change the repr of multivariate polynomials rings. -testall passes, but the test for hash(P) in multi_polynomial_libsingular.pyx needs to be changed for 32 bit machines.

[mwhansen]

Attachment: 764.patch.gz

[mwhansen]

Attachment: const-tut.patch.gz