sage.modular: Deprecate is_... functions

src/sage/matrix/matrix_space.py

@@ -1462,11 +1462,11 @@ def _coerce_map_from_(self, S):
                 return self.has_coerce_map_from(MS)
 
             try:
-                from sage.modular.arithgroup.arithgroup_generic import is_ArithmeticSubgroup
+                from sage.modular.arithgroup.arithgroup_generic import ArithmeticSubgroup
             except ImportError:
                 pass
             else:
-                if is_ArithmeticSubgroup(S):
+                if isinstance(S, ArithmeticSubgroup):
                     return self.has_coerce_map_from(MS)
 
             return False

src/sage/modular/abvar/abvar.py

@@ -43,10 +43,10 @@
 from sage.matrix.special import block_diagonal_matrix, identity_matrix
 from sage.misc.lazy_import import lazy_import
 from sage.misc.misc_c import prod
-from sage.modular.arithgroup.congroup_gamma0 import is_Gamma0
-from sage.modular.arithgroup.congroup_gamma1 import is_Gamma1
-from sage.modular.arithgroup.congroup_gammaH import is_GammaH
-from sage.modular.arithgroup.congroup_generic import is_CongruenceSubgroup
+from sage.modular.arithgroup.congroup_gamma0 import Gamma0_class
+from sage.modular.arithgroup.congroup_gamma1 import Gamma1_class
+from sage.modular.arithgroup.congroup_gammaH import GammaH_class
+from sage.modular.arithgroup.congroup_generic import CongruenceSubgroupBase
 from sage.modular.modform.constructor import Newform
 from sage.modular.modsym.modsym import ModularSymbols
 from sage.modular.modsym.space import ModularSymbolsSpace
@@ -91,6 +91,9 @@ def is_ModularAbelianVariety(x) -> bool:
 
         sage: from sage.modular.abvar.abvar import is_ModularAbelianVariety
         sage: is_ModularAbelianVariety(5)
+        doctest:warning...
+        DeprecationWarning: The function is_ModularAbelianVariety is deprecated; use 'isinstance(..., ModularAbelianVariety_abstract)' instead.
+        See https://github.com/sagemath/sage/issues/38035 for details.
         False
         sage: is_ModularAbelianVariety(J0(37))
         True
@@ -101,6 +104,8 @@ def is_ModularAbelianVariety(x) -> bool:
         sage: is_ModularAbelianVariety(EllipticCurve('37a'))
         False
     """
+    from sage.misc.superseded import deprecation
+    deprecation(38035, "The function is_ModularAbelianVariety is deprecated; use 'isinstance(..., ModularAbelianVariety_abstract)' instead.")
     return isinstance(x, ModularAbelianVariety_abstract)
 
 
@@ -161,7 +166,7 @@ def __init__(self, groups, base_field, is_simple=None, newform_level=None,
             if not isinstance(groups, tuple):
                 raise TypeError("groups must be a tuple")
             for G in groups:
-                if not is_CongruenceSubgroup(G):
+                if not isinstance(G, CongruenceSubgroupBase):
                     raise TypeError("each element of groups must be a congruence subgroup")
         self.__groups = groups
         if is_simple is not None:
@@ -215,7 +220,7 @@ def is_J0(self) -> bool:
             sage: (J0(23) * J0(21)).is_J0()
             False
         """
-        return len(self.groups()) == 1 and is_Gamma0(self.groups()[0]) \
+        return len(self.groups()) == 1 and isinstance(self.groups()[0], Gamma0_class) \
             and self.is_ambient()
 
     def is_J1(self) -> bool:
@@ -237,7 +242,7 @@ def is_J1(self) -> bool:
             sage: J1(23)[0].is_J1()
             False
         """
-        return len(self.groups()) == 1 and is_Gamma1(self.groups()[0]) \
+        return len(self.groups()) == 1 and isinstance(self.groups()[0], Gamma1_class) \
             and self.is_ambient()
 
     ##########################################################################
@@ -605,11 +610,11 @@ def newform_label(self):
             ValueError: self must be simple
         """
         N, G = self.newform_level()
-        if is_Gamma0(G):
+        if isinstance(G, Gamma0_class):
             group = ''
-        elif is_Gamma1(G):
+        elif isinstance(G, Gamma1_class):
             group = 'G1'
-        elif is_GammaH(G):
+        elif isinstance(G, GammaH_class):
             group = 'GH%s' % (str(G._generators_for_H()).replace(' ', ''))
         return '%s%s%s' % (N, cremona_letter_code(self.isogeny_number()), group)
 
@@ -765,7 +770,7 @@ def _simple_isogeny(self, other):
             ...
             NotImplementedError: _simple_isogeny only implemented when both abelian variety have the same ambient product Jacobian
         """
-        if not is_ModularAbelianVariety(other):
+        if not isinstance(other, ModularAbelianVariety_abstract):
             raise TypeError("other must be a modular abelian variety")
 
         if not self.is_simple():
@@ -832,7 +837,7 @@ def in_same_ambient_variety(self, other):
             sage: A.in_same_ambient_variety(J0(11))
             False
         """
-        if not is_ModularAbelianVariety(other):
+        if not isinstance(other, ModularAbelianVariety_abstract):
             return False
         if self.groups() != other.groups():
             return False
@@ -1083,7 +1088,7 @@ def __add__(self, other):
             sage: A+B # long time
             Abelian subvariety of dimension 20 of J0(206)
         """
-        if not is_ModularAbelianVariety(other):
+        if not isinstance(other, ModularAbelianVariety_abstract):
             if other == 0:
                 return self
             raise TypeError("other must be a modular abelian variety")
@@ -1172,7 +1177,7 @@ def __mul__(self, other):
             sage: d[0] * d[1] * J0(11)
             Abelian subvariety of dimension 4 of J0(65) x J0(65) x J0(11)
         """
-        if not is_ModularAbelianVariety(other):
+        if not isinstance(other, ModularAbelianVariety_abstract):
             raise TypeError("other must be a modular abelian variety")
         if other.base_ring() != self.base_ring():
             raise TypeError("self and other must have the same base ring")
@@ -1968,7 +1973,7 @@ def is_subvariety(self, other) -> bool:
             sage: A.is_subvariety(J)
             True
         """
-        if not is_ModularAbelianVariety(other):
+        if not isinstance(other, ModularAbelianVariety_abstract):
             return False
         if self is other:
             return True
@@ -2104,11 +2109,11 @@ def _ambient_repr(self):
         """
         v = []
         for G in self.groups():
-            if is_Gamma0(G):
+            if isinstance(G, Gamma0_class):
                 v.append('J0(%s)' % G.level())
-            elif is_Gamma1(G):
+            elif isinstance(G, Gamma1_class):
                 v.append('J1(%s)' % G.level())
-            elif is_GammaH(G):
+            elif isinstance(G, GammaH_class):
                 v.append('JH(%s,%s)' % (G.level(), G._generators_for_H()))
         return ' x '.join(v)
 
@@ -2125,11 +2130,11 @@ def _ambient_latex_repr(self):
         """
         v = []
         for G in self.groups():
-            if is_Gamma0(G):
+            if isinstance(G, Gamma0_class):
                 v.append('J_0(%s)' % G.level())
-            elif is_Gamma1(G):
+            elif isinstance(G, Gamma1_class):
                 v.append('J_1(%s)' % G.level())
-            elif is_GammaH(G):
+            elif isinstance(G, GammaH_class):
                 v.append('J_H(%s,%s)' % (G.level(), G._generators_for_H()))
         return ' \\times '.join(v)
 
@@ -4099,7 +4104,7 @@ def __add__(self, other):
             sage: sum(D, D[0]) == A
             True
         """
-        if not is_ModularAbelianVariety(other):
+        if not isinstance(other, ModularAbelianVariety_abstract):
             if other == 0:
                 return self
             raise TypeError("sum not defined")
@@ -4397,7 +4402,7 @@ def is_subvariety(self, other):
             sage: D[2].is_subvariety(D[0] + D[1])
             False
         """
-        if not is_ModularAbelianVariety(other):
+        if not isinstance(other, ModularAbelianVariety_abstract):
             return False
         if not isinstance(other, ModularAbelianVariety_modsym_abstract):
             return ModularAbelianVariety_abstract.is_subvariety(self, other)
@@ -4695,7 +4700,7 @@ def component_group_order(self, p):
             self.__component_group[p] = (one, one, one)
             return one
         # Cases that we don't know how to handle yet.
-        if not is_Gamma0(self.group()):
+        if not isinstance(self.group(), Gamma0_class):
             raise NotImplementedError("computation of component group not implemented when group isn't Gamma0")
         if self.level() % (p * p) == 0:
             raise NotImplementedError("computation of component group not implemented when p^2 divides the level")
@@ -4879,7 +4884,7 @@ def tamagawa_number_bounds(self, p):
             mul = 1
         elif N.valuation(p) == 1:
             M = self.modular_symbols(sign=1)
-            if is_Gamma0(M.group()):
+            if isinstance(M.group(), Gamma0_class):
                 g = self.component_group_order(p)
                 W = M.atkin_lehner_operator(p).matrix()
                 if W == -1:
@@ -4941,7 +4946,7 @@ def brandt_module(self, p):
         except KeyError:
             pass
         p = Integer(p)
-        if not is_Gamma0(self.group()):
+        if not isinstance(self.group(), Gamma0_class):
             raise NotImplementedError("Brandt module only defined on Gamma0")
         if not p.is_prime():
             raise ValueError("p must be a prime integer")

src/sage/modular/abvar/abvar_ambient_jacobian.py

@@ -19,7 +19,7 @@
 
 from sage.modular.modsym.modsym import ModularSymbols
 from sage.modular.modform.constructor import Newforms
-from sage.modular.arithgroup.all import is_Gamma0, is_Gamma1
+from sage.modular.arithgroup.all import Gamma0_class, Gamma1_class
 from . import morphism
 
 
@@ -414,7 +414,7 @@ def newform_decomposition(self, names=None):
         if self.dimension() == 0:
             return []
         G = self.group()
-        if not (is_Gamma0(G) or is_Gamma1(G)):
+        if not (isinstance(G, Gamma0_class) or isinstance(G, Gamma1_class)):
             return [S.newform(names=names) for S in self.decomposition()]
         Gtype = G.parent()
         N = G.level()

src/sage/modular/abvar/abvar_newform.py

@@ -19,7 +19,7 @@
 from sage.rings.rational_field import QQ
 
 from sage.modular.modform.element import Newform
-from sage.modular.arithgroup.all import is_Gamma0, is_Gamma1, is_GammaH
+from sage.modular.arithgroup.all import Gamma0_class, Gamma1_class, GammaH_class
 
 from .abvar import ModularAbelianVariety_modsym_abstract
 from . import homspace
@@ -134,11 +134,11 @@ def label(self) -> str:
             '43b'
         """
         G = self.__f.group()
-        if is_Gamma0(G):
+        if isinstance(G, Gamma0_class):
             group = ''
-        elif is_Gamma1(G):
+        elif isinstance(G, Gamma1_class):
             group = 'G1'
-        elif is_GammaH(G):
+        elif isinstance(G, GammaH_class):
             group = 'GH[' + ','.join(str(z) for z in G._generators_for_H()) + ']'
         return '%s%s%s' % (self.level(), cremona_letter_code(self.factor_number()), group)
 

src/sage/modular/abvar/constructor.py

@@ -15,8 +15,8 @@
 
 from sage.rings.integer import Integer
 
-from sage.modular.arithgroup.all import is_CongruenceSubgroup, Gamma0
-from sage.modular.modsym.space import is_ModularSymbolsSpace
+from sage.modular.arithgroup.all import CongruenceSubgroupBase, Gamma0
+from sage.modular.modsym.space import ModularSymbolsSpace
 from .abvar_newform import ModularAbelianVariety_newform
 import sage.modular.modform.element
 from . import abvar
@@ -172,7 +172,7 @@ def AbelianVariety(X):
     """
     if isinstance(X, (int, Integer)):
         X = Gamma0(X)
-    if is_CongruenceSubgroup(X):
+    if isinstance(X, CongruenceSubgroupBase):
         X = X.modular_symbols().cuspidal_submodule()
     elif isinstance(X, str):
         from sage.modular.modform.constructor import Newform
@@ -181,10 +181,10 @@ def AbelianVariety(X):
     elif isinstance(X, sage.modular.modform.element.Newform):
         return ModularAbelianVariety_newform(X)
 
-    if is_ModularSymbolsSpace(X):
+    if isinstance(X, ModularSymbolsSpace):
         return abvar.ModularAbelianVariety_modsym(X)
 
-    if isinstance(X, (tuple,list)) and all(is_CongruenceSubgroup(G) for G in X):
+    if isinstance(X, (tuple,list)) and all(isinstance(G, CongruenceSubgroupBase) for G in X):
         return abvar.ModularAbelianVariety(X)
 
     raise TypeError("X must be an integer, string, newform, modsym space, congruence subgroup or tuple of congruence subgroups")

src/sage/modular/abvar/cuspidal_subgroup.py

@@ -70,7 +70,7 @@
 #*****************************************************************************
 
 from sage.matrix.constructor        import matrix
-from sage.modular.arithgroup.all    import is_Gamma0
+from sage.modular.arithgroup.all    import Gamma0_class
 from sage.modular.cusps             import Cusp
 from sage.rings.infinity            import infinity
 from sage.rings.integer_ring        import ZZ
@@ -172,7 +172,7 @@ def _compute_lattice(self, rational_only=False, rational_subgroup=False):
 
         if rational_only:
             # subgroup generated by differences of rational cusps
-            if not is_Gamma0(A.group()):
+            if not isinstance(A.group(), Gamma0_class):
                 raise NotImplementedError('computation of rational cusps only implemented in Gamma0 case.')
             if not N.is_squarefree():
                 data = [n for n in N.coprime_integers(N) if n >= 2]

src/sage/modular/abvar/finite_subgroup.py

@@ -157,10 +157,10 @@ def __init__(self, abvar, field_of_definition=QQ):
         from sage.categories.fields import Fields
         from sage.categories.finite_enumerated_sets import FiniteEnumeratedSets
         from sage.categories.modules import Modules
-        from .abvar import is_ModularAbelianVariety
+        from .abvar import ModularAbelianVariety_abstract
         if field_of_definition not in Fields():
             raise TypeError("field_of_definition must be a field")
-        if not is_ModularAbelianVariety(abvar):
+        if not isinstance(abvar, ModularAbelianVariety_abstract):
             raise TypeError("abvar must be a modular abelian variety")
         category = Category.join((Modules(ZZ), FiniteEnumeratedSets()))
         Module.__init__(self, ZZ, category=category)
@@ -410,9 +410,9 @@ def intersection(self, other):
             Finite subgroup with invariants [3, 3] over QQ of
              Abelian subvariety of dimension 2 of J0(33)
         """
-        from .abvar import is_ModularAbelianVariety
+        from .abvar import ModularAbelianVariety_abstract
         A = self.abelian_variety()
-        if is_ModularAbelianVariety(other):
+        if isinstance(other, ModularAbelianVariety_abstract):
             amb = other
             B = other
             M = B.lattice().scale(Integer(1)/self.exponent())
@@ -870,10 +870,10 @@ def __init__(self, abvar, lattice, field_of_definition=None, check=True):
         if field_of_definition is None:
             from sage.rings.qqbar import QQbar as field_of_definition
         if check:
-            from .abvar import is_ModularAbelianVariety
+            from .abvar import ModularAbelianVariety_abstract
             if not isinstance(lattice, FreeModule_generic) or lattice.base_ring() != ZZ:
                 raise TypeError("lattice must be a free module over ZZ")
-            if not is_ModularAbelianVariety(abvar):
+            if not isinstance(abvar, ModularAbelianVariety_abstract):
                 raise TypeError("abvar must be a modular abelian variety")
             if not abvar.lattice().is_submodule(lattice):
                 lattice += abvar.lattice()

src/sage/modular/abvar/homspace.py

@@ -228,10 +228,10 @@ def __init__(self, domain, codomain, cat):
             sage: H.homset_category()
             Category of modular abelian varieties over Rational Field
         """
-        from .abvar import is_ModularAbelianVariety
-        if not is_ModularAbelianVariety(domain):
+        from .abvar import ModularAbelianVariety_abstract
+        if not isinstance(domain, ModularAbelianVariety_abstract):
             raise TypeError("domain must be a modular abelian variety")
-        if not is_ModularAbelianVariety(codomain):
+        if not isinstance(codomain, ModularAbelianVariety_abstract):
             raise TypeError("codomain must be a modular abelian variety")
         self._gens = None
         HomsetWithBase.__init__(self, domain, codomain, category=cat)

src/sage/modular/abvar/morphism.py

@@ -446,11 +446,11 @@ def __call__(self, X):
             sage: t2(C)
             Finite subgroup with invariants [2, 2] over QQ of Simple abelian subvariety 33a(1,33) of dimension 1 of J0(33)
         """
-        from .abvar import is_ModularAbelianVariety
+        from .abvar import ModularAbelianVariety_abstract
         from .finite_subgroup import FiniteSubgroup
         if isinstance(X, TorsionPoint):
             return self._image_of_element(X)
-        elif is_ModularAbelianVariety(X):
+        elif isinstance(X, ModularAbelianVariety_abstract):
             return self._image_of_abvar(X)
         elif isinstance(X, FiniteSubgroup):
             return self._image_of_finite_subgroup(X)
@@ -743,11 +743,11 @@ def __init__(self, abvar, n, side="left"):
             sage: T2.parent()
             Endomorphism ring of Abelian variety J0(37) of dimension 2
         """
-        from .abvar import is_ModularAbelianVariety
+        from .abvar import ModularAbelianVariety_abstract
         n = ZZ(n)
         if n <= 0:
             raise ValueError("n must be positive")
-        if not is_ModularAbelianVariety(abvar):
+        if not isinstance(abvar, ModularAbelianVariety_abstract):
             raise TypeError("abvar must be a modular abelian variety")
         self.__abvar = abvar
         self.__n = n