Trac #20011: Deprecate rings/commutative_ring.py and friends

The following modules contain only `is_...` functions and should be
removed:
{{{
sage/rings/commutative_ring.py
sage/rings/dedekind_domain.py
sage/rings/euclidean_domain.py
sage/rings/integral_domain.py
sage/rings/principal_ideal_domain.py
}}}

URL: http://trac.sagemath.org/20011
Reported by: jdemeyer
Ticket author(s): Jeroen Demeyer
Reviewer(s): Travis Scrimshaw

src/sage/categories/commutative_algebra_ideals.py

@@ -52,8 +52,8 @@ def __init__(self, A):
         # TODO: replace by ``A in CommutativeAlgebras(*)`` once a
         # suitable mantra has been implemented for this.
         from sage.algebras.algebra import is_Algebra
-        from sage.rings.commutative_ring import is_CommutativeRing
-        if not (is_Algebra(A) and is_CommutativeRing(A)):
+        from sage.rings.ring import CommutativeRing
+        if not (is_Algebra(A) and isinstance(A, CommutativeRing)):
             raise TypeError("A (=%s) must be a commutative algebra"%A)
         Category_in_ambient.__init__(self, A)
 

src/sage/categories/schemes.py

@@ -139,9 +139,9 @@ def _call_(self, x):
         if is_SchemeMorphism(x):
             return x
         from sage.rings.morphism import is_RingHomomorphism
-        from sage.rings.commutative_ring import is_CommutativeRing
+        from sage.rings.ring import CommutativeRing
         from sage.schemes.generic.spec import Spec
-        if is_CommutativeRing(x):
+        if isinstance(x, CommutativeRing):
             return Spec(x)
         elif is_RingHomomorphism(x):
             A = Spec(x.codomain())

src/sage/geometry/polyhedron/parent.py

@@ -14,8 +14,7 @@
 from sage.structure.unique_representation import UniqueRepresentation
 from sage.modules.free_module import is_FreeModule
 from sage.misc.cachefunc import cached_method
-from sage.rings.commutative_ring import is_CommutativeRing
-from sage.rings.all import ZZ, QQ, RDF
+from sage.rings.all import ZZ, QQ, RDF, CommutativeRing
 from sage.categories.fields import Fields
 
 from sage.geometry.polyhedron.base import Polyhedron_base, is_Polyhedron
@@ -637,7 +636,7 @@ def _get_action_(self, other, op, self_is_left):
                                            extended_self._internal_coerce_map_from(self).__copy__())
             return action
 
-        if op is operator.mul and is_CommutativeRing(other):
+        if op is operator.mul and isinstance(other, CommutativeRing):
             ring = self._coerce_base_ring(other)
             if ring is self.base_ring():
                 return ActedUponAction(other, self, not self_is_left)

src/sage/modular/abvar/homology.py

@@ -40,16 +40,19 @@
     Hecke operator T_7 on Submodule of rank 2 of Integral Homology of Abelian variety J0(43) of dimension 3
 """
 
-###########################################################################
-#       Copyright (C) 2007 William Stein <wstein@gmail.com>               #
-#  Distributed under the terms of the GNU General Public License (GPL)    #
-#                  http://www.gnu.org/licenses/                           #
-###########################################################################
+#*****************************************************************************
+#       Copyright (C) 2007 William Stein <wstein@gmail.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#                  http://www.gnu.org/licenses/
+#*****************************************************************************
 
 
 from sage.modular.hecke.all import HeckeModule_free_module
-from sage.rings.all import Integer, ZZ, QQ
-from sage.rings.commutative_ring import is_CommutativeRing
+from sage.rings.all import Integer, ZZ, QQ, CommutativeRing
 
 import abvar
 
@@ -109,7 +112,7 @@ def __init__(self, abvar, base):
             sage: loads(dumps(H)) == H
             True
         """
-        if not is_CommutativeRing(base):
+        if not isinstance(base, CommutativeRing):
             raise TypeError("base ring must be a commutative ring")
         HeckeModule_free_module.__init__(
             self, base, abvar.level(), weight=2)

src/sage/modular/hecke/module.py

@@ -2,23 +2,17 @@
 Hecke modules
 """
 
-##########################################################################################
+#*****************************************************************************
 #       Copyright (C) 2004,2005,2006 William Stein <wstein@gmail.com>
 #
-#  Distributed under the terms of the GNU General Public License (GPL)
-#
-#    This code is distributed in the hope that it will be useful,
-#    but WITHOUT ANY WARRANTY; without even the implied warranty of
-#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-#    General Public License for more details.
-#
-#  The full text of the GPL is available at:
-#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
 #                  http://www.gnu.org/licenses/
-##########################################################################################
+#*****************************************************************************
 
 import sage.rings.all
-from sage.rings.commutative_ring import is_CommutativeRing
 import sage.arith.all as arith
 import sage.misc.misc as misc
 import sage.modules.module
@@ -79,7 +73,7 @@ def __init__(self, base_ring, level, category=None):
             sage: ModularForms(3, 3).category()
             Category of Hecke modules over Rational Field
         """
-        if not is_CommutativeRing(base_ring):
+        if not isinstance(base_ring, sage.rings.all.CommutativeRing):
             raise TypeError("base_ring must be commutative ring")
 
         from sage.categories.hecke_modules import HeckeModules

src/sage/modular/modform/constructor.py

@@ -19,13 +19,15 @@
 
 """
 
-#########################################################################
-#       Copyright (C) 2004--2006 William Stein <wstein@gmail.com>
-#
-#  Distributed under the terms of the GNU General Public License (GPL)
+#*****************************************************************************
+#       Copyright (C) 2004-2006 William Stein <wstein@gmail.com>
 #
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
 #                  http://www.gnu.org/licenses/
-#########################################################################
+#*****************************************************************************
 
 import weakref
 import re
@@ -34,8 +36,6 @@
 import sage.modular.dirichlet as dirichlet
 import sage.rings.all as rings
 
-from sage.rings.commutative_ring import is_CommutativeRing
-
 import ambient_eps
 import ambient_g0
 import ambient_g1
@@ -123,7 +123,7 @@ def canonical_parameters(group, level, weight, base_ring):
             raise ValueError("group and level do not match.")
         group = arithgroup.Gamma0(m)
 
-    if not is_CommutativeRing(base_ring):
+    if not isinstance(base_ring, rings.CommutativeRing):
         raise TypeError("base_ring (=%s) must be a commutative ring"%base_ring)
 
     # it is *very* important to include the level as part of the data

src/sage/modular/modsym/modsym.py

@@ -86,7 +86,6 @@
 import sage.modular.dirichlet as dirichlet
 import sage.rings.rational_field as rational_field
 import sage.rings.all as rings
-from sage.rings.commutative_ring import is_CommutativeRing
 
 
 def canonical_parameters(group, weight, sign, base_ring):
@@ -129,7 +128,7 @@ def canonical_parameters(group, weight, sign, base_ring):
     if base_ring is None:
         base_ring = rational_field.RationalField()
 
-    if not is_CommutativeRing(base_ring):
+    if not isinstance(base_ring, rings.CommutativeRing):
         raise TypeError("base_ring (=%s) must be a commutative ring"%base_ring)
 
     if not base_ring.is_field():

src/sage/modular/quatalg/brandt.py

@@ -208,9 +208,7 @@ class if `I=aJ` for some `a \in A^*`. (Left `\mathcal{O}`-ideals are
 
 # imports
 from sage.misc.all import prod, verbose
-from sage.rings.all import Integer, ZZ, QQ, PolynomialRing, GF
-
-from sage.rings.commutative_ring import is_CommutativeRing
+from sage.rings.all import Integer, ZZ, QQ, PolynomialRing, GF, CommutativeRing
 
 from sage.algebras.quatalg.quaternion_algebra import QuaternionAlgebra, basis_for_quaternion_lattice
 from sage.algebras.quatalg.quaternion_algebra_cython import rational_matrix_from_rational_quaternions
@@ -297,7 +295,7 @@ def BrandtModule(N, M=1, weight=2, base_ring=QQ, use_cache=True):
         raise ValueError("M must be coprime to N")
     if weight < 2:
         raise ValueError("weight must be at least 2")
-    if not is_CommutativeRing(base_ring):
+    if not isinstance(base_ring, CommutativeRing):
         raise TypeError("base_ring must be a commutative ring")
     key = (N, M, weight, base_ring)
     if use_cache:

src/sage/modules/free_module.py

@@ -168,7 +168,6 @@
 
 from sage.modules.module import Module
 import sage.rings.finite_rings.finite_field_constructor as finite_field
-import sage.rings.integral_domain as integral_domain
 import sage.rings.ring as ring
 import sage.rings.integer_ring
 import sage.rings.rational_field
@@ -378,7 +377,7 @@ def create_object(self, version, key):
                 and base_ring.is_maximal() and base_ring.class_number() == 1:
                 return FreeModule_ambient_pid(base_ring, rank, sparse=sparse)
 
-            elif isinstance(base_ring, integral_domain.IntegralDomain) or base_ring.is_integral_domain():
+            elif isinstance(base_ring, ring.IntegralDomain) or base_ring.is_integral_domain():
                 return FreeModule_ambient_domain(base_ring, rank, sparse=sparse)
 
             else:

src/sage/modules/free_quadratic_module.py

@@ -58,30 +58,20 @@
 """
 
 #*****************************************************************************
+#       Copyright (C) 2008 David Kohel <kohel@iml.univ-mrs.fr>
 #
-#          Copyright (C) 2008 David Kohel <kohel@iml.univ-mrs.fr>
-#
-#  Distributed under the terms of the GNU General Public License (GPL)
-#
-#                        http://www.gnu.org/licenses/
-#
-#         All rights granted to distribute under the GPL, version 2,
-#           or (at your option) any later version of the license.
-#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#                  http://www.gnu.org/licenses/
 #*****************************************************************************
 
-# Python imports
 import weakref
 
-# Sage imports
-
-
 import sage.matrix.matrix_space
-
 import sage.misc.latex as latex
-
 import sage.rings.ring as ring
-import sage.rings.integral_domain as integral_domain
 import sage.rings.integer
 from sage.categories.principal_ideal_domains import PrincipalIdealDomains
 import free_module
@@ -180,7 +170,7 @@ def FreeQuadraticModule(
         M = FreeQuadraticModule_ambient_pid(
             base_ring, rank, sparse=sparse, inner_product_matrix=inner_product_matrix)
 
-    elif isinstance(base_ring, integral_domain.IntegralDomain) or base_ring.is_integral_domain():
+    elif isinstance(base_ring, ring.IntegralDomain) or base_ring.is_integral_domain():
         M = FreeQuadraticModule_ambient_domain(
             base_ring, rank, sparse=sparse, inner_product_matrix=inner_product_matrix)
     else:

src/sage/quadratic_forms/quadratic_form.py

@@ -32,9 +32,8 @@
 from sage.rings.ring import Ring
 from sage.misc.functional import denominator, is_even, is_field
 from sage.arith.all import GCD, LCM
-from sage.rings.principal_ideal_domain import is_PrincipalIdealDomain
 from sage.rings.all import Ideal
-from sage.rings.ring import is_Ring
+from sage.rings.ring import is_Ring, PrincipalIdealDomain
 from sage.matrix.matrix import is_Matrix
 from sage.structure.sage_object import SageObject
 from sage.structure.element import is_Vector
@@ -1436,7 +1435,7 @@ def level(self):
         except AttributeError:
 
             ## Check that the base ring is a PID
-            if not is_PrincipalIdealDomain(self.base_ring()):
+            if not isinstance(self.base_ring(), PrincipalIdealDomain):
                 raise TypeError("Oops!  The level (as a number) is only defined over a Principal Ideal Domain.  Try using level_ideal().")
 
 

src/sage/rings/all.py

@@ -13,12 +13,8 @@
 #*****************************************************************************
 
 # Ring base classes
-from ring import Ring, Field
-from commutative_ring import CommutativeRing
-from integral_domain import IntegralDomain
-from dedekind_domain import DedekindDomain
-from principal_ideal_domain import PrincipalIdealDomain
-from euclidean_domain import EuclideanDomain
+from ring import (Ring, Field, CommutativeRing, IntegralDomain,
+    DedekindDomain, PrincipalIdealDomain, EuclideanDomain)
 
 # Ring element base classes
 from sage.structure.element import (CommutativeAlgebraElement,

src/sage/rings/cfinite_sequence.py

@@ -94,7 +94,7 @@
 
 from sage.categories.fields import Fields
 from sage.misc.inherit_comparison import InheritComparisonClasscallMetaclass
-from sage.rings.commutative_ring import CommutativeRing
+from sage.rings.ring import CommutativeRing
 from sage.rings.integer import Integer
 from sage.rings.integer_ring import ZZ
 from sage.rings.rational_field import QQ

src/sage/rings/commutative_ring.py

@@ -17,6 +17,9 @@
 #                  http://www.gnu.org/licenses/
 #*****************************************************************************
 
+from sage.misc.superseded import deprecation
+deprecation(20011, "the module sage.rings.commutative_ring is deprecated and will be removed")
+
 from sage.rings.ring import CommutativeRing
 
 def is_CommutativeRing(R):
@@ -25,6 +28,9 @@ def is_CommutativeRing(R):
 
     EXAMPLES::
 
+        sage: import sage.rings.commutative_ring
+        doctest:...: DeprecationWarning: the module sage.rings.commutative_ring is deprecated and will be removed
+        See http://trac.sagemath.org/20011 for details.
         sage: sage.rings.commutative_ring.is_CommutativeRing(ZZ)
         True
     """

src/sage/rings/dedekind_domain.py

@@ -17,6 +17,9 @@
 #                  http://www.gnu.org/licenses/
 #*****************************************************************************
 
+from sage.misc.superseded import deprecation
+deprecation(20011, "the module sage.rings.dedekind_domain is deprecated and will be removed")
+
 from sage.rings.ring import DedekindDomain
 
 def is_DedekindDomain(R):
@@ -25,6 +28,9 @@ def is_DedekindDomain(R):
 
     EXAMPLES::
 
+        sage: import sage.rings.dedekind_domain
+        doctest:...: DeprecationWarning: the module sage.rings.dedekind_domain is deprecated and will be removed
+        See http://trac.sagemath.org/20011 for details.
         sage: sage.rings.dedekind_domain.is_DedekindDomain(DedekindDomain(QQ))
         True
     """

src/sage/rings/euclidean_domain.py

@@ -17,6 +17,9 @@
 #                  http://www.gnu.org/licenses/
 #*****************************************************************************
 
+from sage.misc.superseded import deprecation
+deprecation(20011, "the module sage.rings.euclidean_domain is deprecated and will be removed")
+
 from sage.rings.ring import EuclideanDomain
 
 def is_EuclideanDomain(R):
@@ -25,6 +28,9 @@ def is_EuclideanDomain(R):
 
     EXAMPLES::
 
+        sage: import sage.rings.euclidean_domain
+        doctest:...: DeprecationWarning: the module sage.rings.euclidean_domain is deprecated and will be removed
+        See http://trac.sagemath.org/20011 for details.
         sage: sage.rings.euclidean_domain.is_EuclideanDomain(EuclideanDomain(ZZ))
         True
     """

src/sage/rings/finite_rings/integer_mod_ring.py

@@ -62,7 +62,6 @@
 import sage.misc.prandom as random
 
 from sage.arith.all import factor, primitive_root, CRT_basis
-import sage.rings.commutative_ring as commutative_ring
 import sage.rings.ring as ring
 import integer_mod
 import sage.rings.integer as integer
@@ -1506,8 +1505,8 @@ def random_element(self, bound=None):
             sage: R.random_element(2) in [R(16), R(17), R(0), R(1), R(2)]
             True
         """
-        if not (bound is None):
-            return commutative_ring.CommutativeRing.random_element(self, bound)
+        if bound is not None:
+            return ring.CommutativeRing.random_element(self, bound)
         a = random.randint(0,self.order()-1)
         return self(a)
 

src/sage/rings/ideal.py

@@ -31,7 +31,6 @@
 
 import sage.misc.latex as latex
 import sage.rings.ring
-import commutative_ring
 from sage.structure.element import MonoidElement
 from sage.interfaces.singular import singular as singular_default
 import sage.rings.infinity
@@ -189,7 +188,7 @@ def Ideal(*args, **kwds):
         R = first
         gens = args[1:]
 
-    if not commutative_ring.is_CommutativeRing(R):
+    if not isinstance(R, sage.rings.ring.CommutativeRing):
         raise TypeError("R must be a commutative ring")
 
     return R.ideal(*gens, **kwds)