Merge sagemath#32610

src/sage/dynamics/arithmetic_dynamics/projective_ds.py

@@ -88,8 +88,8 @@ class initialization directly.
 from sage.rings.qqbar import QQbar, number_field_elements_from_algebraics
 from sage.rings.quotient_ring import QuotientRing_generic
 from sage.rings.rational_field import QQ
-from sage.rings.real_double import RDF
-from sage.rings.real_mpfr import (RealField, is_RealField)
+import sage.rings.abc
+from sage.rings.real_mpfr import RealField
 from sage.schemes.generic.morphism import SchemeMorphism_polynomial
 from sage.schemes.projective.projective_subscheme import AlgebraicScheme_subscheme_projective
 from sage.schemes.projective.projective_morphism import (
@@ -2062,10 +2062,10 @@ def canonical_height(self, P, **kwds):
 
         # Archimedean local heights
         # :: WARNING: If places is fed the default Sage precision of 53 bits,
-        # it uses Real or Complex Double Field in place of RealField(prec) or ComplexField(prec)
-        # the function is_RealField does not identify RDF as real, so we test for that ourselves.
+        # it uses Real or Complex Double Field in place of RealField(prec) or ComplexField(prec).
+        # RDF is an instance of a separate class.
         for v in emb:
-            if is_RealField(v.codomain()) or v.codomain() is RDF:
+            if isinstance(v.codomain(), (sage.rings.abc.RealField, sage.rings.abc.RealDoubleField)):
                 dv = R.one()
             else:
                 dv = R(2)

src/sage/functions/orthogonal_polys.py

@@ -304,8 +304,7 @@
 from sage.misc.latex import latex
 from sage.rings.all import ZZ, QQ, RR, CC
 from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
-from sage.rings.real_mpfr import is_RealField
-from sage.rings.complex_mpfr import is_ComplexField
+import sage.rings.abc
 
 from sage.symbolic.function import BuiltinFunction, GinacFunction
 from sage.symbolic.expression import Expression
@@ -672,7 +671,7 @@ def _evalf_(self, n, x, **kwds):
         except KeyError:
             real_parent = parent(x)
 
-            if not is_RealField(real_parent) and not is_ComplexField(real_parent):
+            if not isinstance(real_parent, (sage.rings.abc.RealField, sage.rings.abc.ComplexField)):
                 # parent is not a real or complex field: figure out a good parent
                 if x in RR:
                     x = RR(x)
@@ -681,7 +680,7 @@ def _evalf_(self, n, x, **kwds):
                     x = CC(x)
                     real_parent = CC
 
-        if not is_RealField(real_parent) and not is_ComplexField(real_parent):
+        if not isinstance(real_parent, (sage.rings.abc.RealField, sage.rings.abc.ComplexField)):
             raise TypeError("cannot evaluate chebyshev_T with parent {}".format(real_parent))
 
         from sage.libs.mpmath.all import call as mpcall
@@ -1031,7 +1030,7 @@ def _evalf_(self, n, x, **kwds):
         except KeyError:
             real_parent = parent(x)
 
-            if not is_RealField(real_parent) and not is_ComplexField(real_parent):
+            if not isinstance(real_parent, (sage.rings.abc.RealField, sage.rings.abc.ComplexField)):
                 # parent is not a real or complex field: figure out a good parent
                 if x in RR:
                     x = RR(x)
@@ -1040,7 +1039,7 @@ def _evalf_(self, n, x, **kwds):
                     x = CC(x)
                     real_parent = CC
 
-        if not is_RealField(real_parent) and not is_ComplexField(real_parent):
+        if not isinstance(real_parent, (sage.rings.abc.RealField, sage.rings.abc.ComplexField)):
             raise TypeError("cannot evaluate chebyshev_U with parent {}".format(real_parent))
 
         from sage.libs.mpmath.all import call as mpcall

src/sage/functions/special.py

@@ -158,8 +158,8 @@
 #                  https://www.gnu.org/licenses/
 # ****************************************************************************
 
+import sage.rings.abc
 from sage.rings.integer import Integer
-from sage.rings.complex_mpfr import ComplexField
 from sage.misc.latex import latex
 from sage.rings.integer_ring import ZZ
 from sage.symbolic.constants import pi
@@ -362,10 +362,9 @@ def elliptic_j(z, prec=53):
         sage: (-elliptic_j(tau, 100).real().round())^(1/3)
         640320
     """
-
     CC = z.parent()
-    from sage.rings.complex_mpfr import is_ComplexField
-    if not is_ComplexField(CC):
+    if not isinstance(CC, sage.rings.abc.ComplexField):
+        from sage.rings.complex_mpfr import ComplexField
         CC = ComplexField(prec)
         try:
             z = CC(z)

src/sage/matrix/misc.pyx

@@ -40,7 +40,7 @@ from sage.rings.rational_field import QQ
 from sage.rings.integer cimport Integer
 from sage.arith.all import previous_prime, CRT_basis
 
-from sage.rings.real_mpfr import  is_RealField
+from sage.rings.real_mpfr cimport RealField_class
 from sage.rings.real_mpfr cimport RealNumber
 
 
@@ -510,7 +510,7 @@ def hadamard_row_bound_mpfr(Matrix A):
         ...
         OverflowError: cannot convert float infinity to integer
     """
-    if not is_RealField(A.base_ring()):
+    if not isinstance(A.base_ring(), RealField_class):
         raise TypeError("A must have base field an mpfr real field.")
 
     cdef RealNumber a, b

src/sage/modular/dirichlet.py

@@ -68,7 +68,7 @@
 
 from sage.categories.map import Map
 from sage.rings.rational_field import is_RationalField
-from sage.rings.complex_mpfr import is_ComplexField
+import sage.rings.abc
 from sage.rings.qqbar import is_AlgebraicField
 from sage.rings.ring import is_Ring
 
@@ -1153,7 +1153,7 @@ def _pari_init_(self):
 
         # now compute the input for pari (list of exponents)
         P = self.parent()
-        if is_ComplexField(P.base_ring()):
+        if isinstance(P.base_ring(), sage.rings.abc.ComplexField):
             zeta = P.zeta()
             zeta_argument = zeta.argument()
             v = [int(x.argument() / zeta_argument) for x in values_on_gens]
@@ -1345,7 +1345,7 @@ def gauss_sum(self, a=1):
         K = G.base_ring()
         chi = self
         m = G.modulus()
-        if is_ComplexField(K):
+        if isinstance(K, sage.rings.abc.ComplexField):
             return self.gauss_sum_numerical(a=a)
         elif is_AlgebraicField(K):
             L = K
@@ -1422,7 +1422,7 @@ def gauss_sum_numerical(self, prec=53, a=1):
         """
         G = self.parent()
         K = G.base_ring()
-        if is_ComplexField(K):
+        if isinstance(K, sage.rings.abc.ComplexField):
 
             def phi(t):
                 return t
@@ -2138,7 +2138,7 @@ def element(self):
         """
         P = self.parent()
         M = P._module
-        if is_ComplexField(P.base_ring()):
+        if isinstance(P.base_ring(), sage.rings.abc.ComplexField):
             zeta = P.zeta()
             zeta_argument = zeta.argument()
             v = M([int(round(x.argument() / zeta_argument))
@@ -2607,7 +2607,7 @@ def _zeta_powers(self):
         w = [a]
         zeta = self.zeta()
         zeta_order = self.zeta_order()
-        if is_ComplexField(R):
+        if isinstance(R, sage.rings.abc.ComplexField):
             for i in range(1, zeta_order):
                 a = a * zeta
                 a._set_multiplicative_order(zeta_order / gcd(zeta_order, i))

src/sage/modules/free_module.py

@@ -170,6 +170,7 @@
 from sage.modules.module import Module
 import sage.rings.finite_rings.finite_field_constructor as finite_field
 import sage.rings.ring as ring
+import sage.rings.abc
 import sage.rings.integer_ring
 import sage.rings.rational_field
 import sage.rings.abc

src/sage/probability/random_variable.py

@@ -15,10 +15,10 @@
 #                  https://www.gnu.org/licenses/
 # ****************************************************************************
 
+import sage.rings.abc
 from sage.structure.parent import Parent
 from sage.functions.log import log
 from sage.functions.all import sqrt
-from sage.rings.real_mpfr import (RealField, is_RealField)
 from sage.rings.rational_field import is_RationalField
 from sage.sets.set import Set
 from pprint import pformat
@@ -83,6 +83,7 @@ def __init__(self, X, f, codomain=None, check=False):
         if check:
             raise NotImplementedError("Not implemented")
         if codomain is None:
+            from sage.rings.real_mpfr import RealField
             RR = RealField()
         else:
             RR = codomain
@@ -337,8 +338,9 @@ def __init__(self, X, P, codomain=None, check=False):
             1.50000000000000
         """
         if codomain is None:
+            from sage.rings.real_mpfr import RealField
             codomain = RealField()
-        if not is_RealField(codomain) and not is_RationalField(codomain):
+        if not isinstance(codomain, sage.rings.abc.RealField) and not is_RationalField(codomain):
             raise TypeError("Argument codomain (= %s) must be the reals or rationals" % codomain)
         if check:
             one = sum(P.values())

src/sage/quadratic_forms/special_values.py

@@ -9,13 +9,12 @@
 
 from sage.combinat.combinat import bernoulli_polynomial
 from sage.misc.functional import denominator
-from sage.rings.all import RealField
 from sage.arith.all import kronecker_symbol, bernoulli, factorial, fundamental_discriminant
 from sage.rings.infinity import infinity
 from sage.rings.integer_ring import ZZ
 from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
 from sage.rings.rational_field import QQ
-from sage.rings.real_mpfr import is_RealField
+import sage.rings.abc
 from sage.symbolic.constants import pi, I
 
 # ---------------- The Gamma Function  ------------------
@@ -278,9 +277,10 @@ def quadratic_L_function__numerical(n, d, num_terms=1000):
         ....:         print("Oops! We have a problem at d = {}: exact = {}, numerical = {}".format(d, RR(quadratic_L_function__exact(1, d)), RR(quadratic_L_function__numerical(1, d))))
     """
     # Set the correct precision if it is given (for n).
-    if is_RealField(n.parent()):
+    if isinstance(n.parent(), sage.rings.abc.RealField):
         R = n.parent()
     else:
+        from sage.rings.real_mpfr import RealField
         R = RealField()
 
     if n < 0:

src/sage/rings/complex_double.pyx

@@ -111,18 +111,28 @@ from sage.structure.richcmp cimport rich_to_bool
 cimport gmpy2
 gmpy2.import_gmpy2()
 
+
 def is_ComplexDoubleField(x):
     """
     Return ``True`` if ``x`` is the complex double field.
 
+    This function is deprecated. Use :func:`isinstance` with
+    :class:`~sage.rings.abc.ComplexDoubleField` instead.
+
     EXAMPLES::
 
         sage: from sage.rings.complex_double import is_ComplexDoubleField
         sage: is_ComplexDoubleField(CDF)
+        doctest:warning...
+        DeprecationWarning: is_ComplexDoubleField is deprecated;
+        use isinstance(..., sage.rings.abc.ComplexDoubleField) instead
+        See https://trac.sagemath.org/32610 for details.
         True
         sage: is_ComplexDoubleField(ComplexField(53))
         False
     """
+    from sage.misc.superseded import deprecation
+    deprecation(32610, 'is_ComplexDoubleField is deprecated; use isinstance(..., sage.rings.abc.ComplexDoubleField) instead')
     return isinstance(x, ComplexDoubleField_class)
 
 

src/sage/rings/complex_mpfr.pyx

@@ -157,22 +157,33 @@ def is_ComplexNumber(x):
     """
     return isinstance(x, ComplexNumber)
 
+
 def is_ComplexField(x):
     """
     Check if ``x`` is a :class:`complex field <ComplexField_class>`.
 
+    This function is deprecated. Use :func:`isinstance` with
+    :class:`~sage.rings.abc.ComplexField` instead.
+
     EXAMPLES::
 
         sage: from sage.rings.complex_mpfr import is_ComplexField as is_CF
         sage: is_CF(ComplexField())
+        doctest:warning...
+        DeprecationWarning: is_ComplexField is deprecated;
+        use isinstance(..., sage.rings.abc.ComplexField) instead
+        See https://trac.sagemath.org/32610 for details.
         True
         sage: is_CF(ComplexField(12))
         True
         sage: is_CF(CC)
         True
     """
+    from sage.misc.superseded import deprecation
+    deprecation(32610, 'is_ComplexField is deprecated; use isinstance(..., sage.rings.abc.ComplexField) instead')
     return isinstance(x, ComplexField_class)
 
+
 cache = {}
 def ComplexField(prec=53, names=None):
     """
@@ -543,7 +554,7 @@ class ComplexField_class(sage.rings.abc.ComplexField):
         RR = self._real_field()
         if RR.has_coerce_map_from(S):
             return RRtoCC(RR, self) * RR._internal_coerce_map_from(S)
-        if is_ComplexField(S):
+        if isinstance(S, ComplexField_class):
             if self._prec <= S._prec:
                 return self._generic_coerce_map(S)
             else:

src/sage/rings/number_field/number_field.py

@@ -9945,16 +9945,14 @@ def hilbert_symbol(self, a, b, P = None):
             if P.domain() is not self:
                 raise ValueError("Domain of P (=%s) should be self (=%s) in self.hilbert_symbol" % (P, self))
             codom = P.codomain()
-            from sage.rings.complex_mpfr import is_ComplexField
             from sage.rings.complex_interval_field import is_ComplexIntervalField
-            from sage.rings.real_mpfr import is_RealField
-            from sage.rings.all import (AA, CDF, QQbar, RDF)
-            if is_ComplexField(codom) or is_ComplexIntervalField(codom) or \
-                                         codom is CDF or codom is QQbar:
+            from sage.rings.all import (AA, QQbar)
+            if isinstance(codom, (sage.rings.abc.ComplexField, sage.rings.abc.ComplexDoubleField)) or is_ComplexIntervalField(codom) or \
+                                         codom is QQbar:
                 if P(self.gen()).imag() == 0:
                     raise ValueError("Possibly real place (=%s) given as complex embedding in hilbert_symbol. Is it real or complex?" % P)
                 return 1
-            if is_RealField(codom) or codom is RDF or codom is AA:
+            if isinstance(codom, (sage.rings.abc.RealField, sage.rings.abc.RealDoubleField)) or codom is AA:
                 if P(a) > 0 or P(b) > 0:
                     return 1
                 return -1
@@ -12317,7 +12315,7 @@ def refine_embedding(e, prec=None):
         return e
 
     # We first compute all the embeddings at the new precision:
-    if sage.rings.real_mpfr.is_RealField(RC) or RC in (RDF, RLF):
+    if isinstance(RC, (sage.rings.abc.RealField, sage.rings.abc.RealDoubleField)) or RC == RLF:
         if prec == Infinity:
             elist = K.embeddings(sage.rings.qqbar.AA)
         else:

src/sage/rings/number_field/number_field_element.pyx

@@ -3945,8 +3945,7 @@ cdef class NumberFieldElement(FieldElement):
         if a <= Kv.one():
             return Kv.zero()
         ht = a.log()
-        from sage.rings.real_mpfr import is_RealField
-        if weighted and not is_RealField(Kv):
+        if weighted and not isinstance(Kv, sage.rings.abc.RealField):
             ht*=2
         return ht
 

src/sage/rings/polynomial/multi_polynomial_libsingular.pyx

@@ -224,8 +224,7 @@ from sage.rings.polynomial.polynomial_ring import is_PolynomialRing
 from sage.rings.finite_rings.finite_field_prime_modn import FiniteField_prime_modn
 from sage.rings.rational cimport Rational
 from sage.rings.rational_field import QQ
-from sage.rings.complex_mpfr import is_ComplexField
-from sage.rings.real_mpfr import is_RealField
+import sage.rings.abc
 from sage.rings.integer_ring import is_IntegerRing, ZZ
 from sage.rings.integer cimport Integer
 from sage.rings.integer import GCD_list
@@ -1366,14 +1365,14 @@ cdef class MPolynomialRing_libsingular(MPolynomialRing_base):
 
         base_ring = self.base_ring()
 
-        if is_RealField(base_ring):
+        if isinstance(base_ring, sage.rings.abc.RealField):
             # singular converts to bits from base_10 in mpr_complex.cc by:
             #  size_t bits = 1 + (size_t) ((float)digits * 3.5);
             precision = base_ring.precision()
             digits = ceil((2*precision - 2)/7.0)
             self.__singular = singular.ring("(real,%d,0)"%digits, _vars, order=order)
 
-        elif is_ComplexField(base_ring):
+        elif isinstance(base_ring, sage.rings.abc.ComplexField):
             # singular converts to bits from base_10 in mpr_complex.cc by:
             #  size_t bits = 1 + (size_t) ((float)digits * 3.5);
             precision = base_ring.precision()

src/sage/rings/polynomial/polynomial_ring.py

@@ -165,7 +165,7 @@
 from sage.misc.cachefunc import cached_method
 from sage.misc.lazy_attribute import lazy_attribute
 
-from sage.rings.real_mpfr import is_RealField
+import sage.rings.abc
 from sage.rings.fraction_field_element import FractionFieldElement
 from sage.rings.finite_rings.element_base import FiniteRingElement
 
@@ -1995,7 +1995,7 @@ def __init__(self, base_ring, name="x", sparse=False, element_class=None, catego
                 else:
                     from sage.rings.polynomial.polynomial_number_field import Polynomial_relative_number_field_dense
                     element_class = Polynomial_relative_number_field_dense
-            elif is_RealField(base_ring):
+            elif isinstance(base_ring, sage.rings.abc.RealField):
                 element_class = PolynomialRealDense
             elif isinstance(base_ring, sage.rings.complex_arb.ComplexBallField):
                 from sage.rings.polynomial.polynomial_complex_arb import Polynomial_complex_arb