WIP - Change design

src/sage/rings/polynomial/commutative_polynomial.pxd

@@ -0,0 +1,5 @@
+from sage.structure.element cimport CommutativeAlgebraElement
+
+
+cdef class CommutativePolynomial(CommutativeAlgebraElement):
+    pass

src/sage/rings/polynomial/commutative_polynomial.pyx

@@ -0,0 +1,10 @@
+cdef class CommutativePolynomial(CommutativeAlgebraElement):
+    r"""
+    Abstract base class for commutative polynomials in any number of variables
+
+    It is a common base for :class:`~sage.rings.polynomial.polynomial_element.Polynomial`,
+    :class:`~sage.rings.polynomial.multi_polynomial.MPolynomial`, and
+    :class:`~sage.rings.polynomial.infinite_polynomial_element.InfinitePolynomial`.
+    """
+
+    pass

src/sage/rings/polynomial/infinite_polynomial_element.py

@@ -94,11 +94,13 @@
 from sage.structure.richcmp import richcmp
 from sage.misc.cachefunc import cached_method
 from sage.misc.inherit_comparison import InheritComparisonClasscallMetaclass
-from sage.structure.element import RingElement, MPolynomial, InfinitePolynomial as InfinitePolynomial_base
+from sage.structure.element import RingElement
+from .commutative_polynomial import CommutativePolynomial
+from .multi_polynomial import MPolynomial
 import copy
 
 
-class InfinitePolynomial(InfinitePolynomial_base, metaclass=InheritComparisonClasscallMetaclass):
+class InfinitePolynomial(CommutativePolynomial, metaclass=InheritComparisonClasscallMetaclass):
     """
     Create an element of a Polynomial Ring with a Countably Infinite Number of Variables.
 

src/sage/rings/polynomial/multi_polynomial.pxd

@@ -1,7 +1,11 @@
-from sage.structure.element cimport MPolynomial as MPolynomial_base
+from .commutative_polynomial cimport CommutativePolynomial
 
-cdef class MPolynomial(MPolynomial_base):
+
+cdef class MPolynomial(CommutativePolynomial):
     cdef long _hash_c(self) except -1
     cpdef _mod_(self, right)
     cpdef dict _mpoly_dict_recursive(self, tuple vars=*, base_ring=*)
 
+
+cdef class MPolynomial_libsingular(MPolynomial):
+    pass

src/sage/rings/polynomial/multi_polynomial.pyx

@@ -33,7 +33,7 @@ from sage.rings.real_mpfr import RealField_class,RealField
 from sage.rings.polynomial.polydict cimport ETuple
 from sage.rings.polynomial.polynomial_element cimport Polynomial
 
-cdef class MPolynomial(MPolynomial_base):
+cdef class MPolynomial(CommutativePolynomial):
 
     ####################
     # Some standard conversions
@@ -2623,3 +2623,26 @@ cdef remove_from_tuple(e, int ind):
         return w[0]
     else:
         return tuple(w)
+
+
+cdef class MPolynomial_libsingular(MPolynomial):
+    r"""
+    Abstract base class for :class:`~sage.rings.polynomial.multi_polynomial_libsingular.MPolynomial_libsingular`
+
+    This class is defined for the purpose of :func:`isinstance` tests.  It should not be
+    instantiated.
+
+    EXAMPLES::
+
+        sage: R1.<x> = QQ[]
+        sage: isinstance(x, sage.rings.polynomial.multi_polynomial.MPolynomial_libsingular)
+        False
+        sage: R2.<y,z> = QQ[]
+        sage: isinstance(y, sage.rings.polynomial.multi_polynomial.MPolynomial_libsingular)
+        True
+
+    By design, there is a unique direct subclass::
+
+        sage: len(sage.rings.polynomial.multi_polynomial.MPolynomial_libsingular.__subclasses__()) <= 1
+        True
+    """

src/sage/rings/polynomial/multi_polynomial_libsingular.pxd

@@ -1,11 +1,11 @@
 from sage.libs.singular.decl cimport poly, ring
 
-from sage.rings.polynomial.multi_polynomial cimport MPolynomial
+from sage.rings.polynomial.multi_polynomial cimport MPolynomial_libsingular as MPolynomial_libsingular_base
 from sage.rings.polynomial.multi_polynomial_ring_base cimport MPolynomialRing_base
 
 cdef class MPolynomialRing_libsingular
 
-cdef class MPolynomial_libsingular(MPolynomial):
+cdef class MPolynomial_libsingular(MPolynomial_libsingular_base):
     cdef poly *_poly
     cdef ring *_parent_ring
     cpdef _add_(self, other)

src/sage/rings/polynomial/multi_polynomial_libsingular.pyx

@@ -1896,7 +1896,7 @@ def unpickle_MPolynomialRing_libsingular(base_ring, names, term_order):
     return _multi_variate(base_ring, tuple(names), None, term_order, None)
 
 
-cdef class MPolynomial_libsingular(MPolynomial):
+cdef class MPolynomial_libsingular(MPolynomial_libsingular_base):
     """
     A multivariate polynomial implemented using libSINGULAR.
     """

src/sage/rings/polynomial/polynomial_element.pxd

@@ -1,12 +1,12 @@
 from sage.structure.element import Element
 from sage.structure.element cimport Element, CommutativeAlgebraElement, ModuleElement
-from sage.structure.element cimport Polynomial as Polynomial_base
 from sage.structure.parent cimport Parent
 from sage.rings.integer cimport Integer
+from .commutative_polynomial cimport CommutativePolynomial
 from .polynomial_compiled cimport CompiledPolynomialFunction
 
 
-cdef class Polynomial(Polynomial_base):
+cdef class Polynomial(CommutativePolynomial):
     cdef Polynomial _new_generic(self, list coeffs)
     cdef char _is_gen
     cdef CompiledPolynomialFunction _compiled

src/sage/structure/element.pxd

@@ -239,15 +239,6 @@ cdef class CommutativeAlgebraElement(CommutativeRingElement):
 cdef class Expression(CommutativeRingElement):
     pass
 
-cdef class CommutativePolynomial(CommutativeAlgebraElement):
-    pass
-
-cdef class Polynomial(CommutativePolynomial):
-    pass
-
-cdef class MPolynomial(CommutativePolynomial):
-    pass
-
 cdef class InfinityElement(RingElement):
     pass
 

src/sage/structure/element.pyx

@@ -47,10 +47,6 @@ abstract base classes.
                                     EuclideanDomainElement
                         FieldElement
                         CommutativeAlgebraElement
-                            CommutativePolynomial
-                                Polynomial
-                                MPolynomial
-                                InfinitePolynomial
                         Expression
                     AlgebraElement
                         Matrix
@@ -4310,93 +4306,6 @@ cdef class CommutativeAlgebraElement(CommutativeRingElement):
 
     ##############################################
 
-cdef class CommutativePolynomial(CommutativeAlgebraElement):
-    r"""
-    Abstract base class for commutative polynomials in any number of variables
-
-    It is a common base for :class:`Polynomial`, :class:`MPolynomial`, and
-    :class:`InfinitePolynomial`.
-    """
-
-    pass
-
-    ##############################################
-
-cdef class Polynomial(CommutativePolynomial):
-    r"""
-    Abstract base class for :class:`~sage.rings.polynomial.polynomial_element.Polynomial`
-
-    This class is defined for the purpose of :func:`isinstance` tests.  It should not be
-    instantiated.
-
-    EXAMPLES::
-
-        sage: R1.<x> = QQ[]
-        sage: isinstance(x, sage.structure.element.Polynomial)
-        True
-        sage: R2.<y,z> = QQ[]
-        sage: isinstance(y, sage.structure.element.Polynomial)
-        False
-
-    By design, there is a unique direct subclass::
-
-        sage: len(sage.structure.element.Polynomial.__subclasses__()) <= 1
-        True
-    """
-
-    pass
-
-    ##############################################
-
-cdef class MPolynomial(CommutativePolynomial):
-    r"""
-    Abstract base class for :class:`~sage.rings.polynomial.multi_polynomial.MPolynomial`
-
-    This class is defined for the purpose of :func:`isinstance` tests.  It should not be
-    instantiated.
-
-    EXAMPLES::
-
-        sage: R1.<x> = QQ[]
-        sage: isinstance(x, sage.structure.element.MPolynomial)
-        False
-        sage: R2.<y,z> = QQ[]
-        sage: isinstance(y, sage.structure.element.MPolynomial)
-        True
-
-    By design, there is a unique direct subclass::
-
-        sage: len(sage.structure.element.MPolynomial.__subclasses__()) <= 1
-        True
-    """
-
-    pass
-
-    ##############################################
-
-cdef class InfinitePolynomial(CommutativePolynomial):
-    r"""
-    Abstract base class for :class:`~sage.rings.polynomial.infinite_polynomial_element.InfinitePolynomial`
-
-    This class is defined for the purpose of :func:`isinstance` tests.  It should not be
-    instantiated.
-
-    EXAMPLES::
-
-        sage: X.<x> = InfinitePolynomialRing(QQ)
-        sage: isinstance(x[0], sage.structure.element.InfinitePolynomial)
-        True
-
-    By design, there is a unique direct subclass::
-
-        sage: len(sage.structure.element.InfinitePolynomial.__subclasses__()) <= 1
-        True
-    """
-
-    pass
-
-    ##############################################
-
 def is_InfinityElement(x):
     """
     Return ``True`` if x is of type InfinityElement.