PolynomialFunctor: Keep track of implementation

Author: Matthias Koeppe

src/sage/categories/pushout.py

@@ -833,7 +833,7 @@ class PolynomialFunctor(ConstructionFunctor):
     """
     rank = 9
 
-    def __init__(self, var, multi_variate=False, sparse=False):
+    def __init__(self, var, multi_variate=False, sparse=False, implementation=None):
         """
         TESTS::
 
@@ -857,6 +857,7 @@ def __init__(self, var, multi_variate=False, sparse=False):
         self.var = var
         self.multi_variate = multi_variate
         self.sparse = sparse
+        self.implementation = implementation
 
     def _apply_functor(self, R):
         """
@@ -870,7 +871,10 @@ def _apply_functor(self, R):
 
         """
         from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
-        return PolynomialRing(R, self.var, sparse=self.sparse)
+        kwds = {}
+        if self.implementation:
+            kwds['implementation'] = self.implementation
+        return PolynomialRing(R, self.var, sparse=self.sparse, **kwds)
 
     def _apply_functor_to_morphism(self, f):
         """

src/sage/rings/polynomial/polynomial_ring.py

@@ -619,6 +619,9 @@ def flattening_morphism(self):
             return IdentityMorphism(self)
 
     def construction(self):
+        """
+        Return the construction functor.
+        """
         return categories.pushout.PolynomialFunctor(self.variable_name(), sparse=self.__is_sparse), self.base_ring()
 
     def completion(self, p, prec=20, extras=None):
@@ -1951,6 +1954,15 @@ def _repr_(self):
         s = PolynomialRing_commutative._repr_(self)
         return s + self._implementation_repr
 
+    def construction(self):
+        """
+        Return the construction functor.
+        """
+        implementation = None
+        if 'NTL' in self._implementation_repr:
+            implementation = 'NTL'
+        return categories.pushout.PolynomialFunctor(self.variable_name(), sparse=self.is_sparse(),
+                                                    implementation=implementation), self.base_ring()
 
 class PolynomialRing_field(PolynomialRing_integral_domain,
                            ring.PrincipalIdealDomain):