sf fixes

src/sage/categories/pushout.py

@@ -35,7 +35,7 @@
 lazy_import('sage.categories.commutative_rings', 'CommutativeRings')
 lazy_import('sage.categories.groups', 'Groups')
 lazy_import('sage.categories.objects', 'Objects')
-lazy_import('sage.categories.rings', 'Rings', at_startup=True)
+lazy_import('sage.categories.rings', 'Rings')
 
 # TODO, think through the rankings, and override pushout where necessary.
 

src/sage/combinat/sf/orthotriang.py

@@ -102,7 +102,7 @@ def __init__(self, Sym, base, scalar, prefix, basis_name, leading_coeff):
         TESTS::
 
             sage: TestSuite(s).run(elements=[s[1,1]+2*s[2], s[1]+3*s[1,1]])
-            sage: TestSuite(s).run(skip=["_test_associativity", "_test_prod", '_test_construction'])  # long time (7s on sage.math, 2011)
+            sage: TestSuite(s).run(skip=["_test_associativity", "_test_prod"])  # long time (7s on sage.math, 2011)
 
         Note: ``s.an_element()`` is of degree 4; so we skip
         ``_test_associativity`` and ``_test_prod`` which involve

src/sage/combinat/sf/sf.py

@@ -845,7 +845,6 @@ class function on the symmetric group where the elements
         - Devise a mechanism so that pickling bases of symmetric
           functions pickles the coercions which have a cache.
     """
-
     def __init__(self, R):
         r"""
         Initialization of ``self``.

src/sage/combinat/sf/sfa.py

@@ -412,6 +412,17 @@ def is_integral_domain(self, proof=True):
             """
             return self.base_ring().is_integral_domain()
 
+        def fraction_field(self):
+            if not self.is_integral_domain():
+                raise TypeError("self must be an integral domain.")
+            if hasattr(self, "__fraction_field") and self.__fraction_field is not None:
+                return self.__fraction_field
+            else:
+                import sage.rings.fraction_field
+                K = sage.rings.fraction_field.FractionField_generic(self)
+                self.__fraction_field = K
+            return self.__fraction_field
+
         def is_field(self, proof=True):
             """
             Return whether ``self`` is a field. (It is not.)
@@ -1848,6 +1859,9 @@ def __init__(self, Sym, basis_name=None, prefix=None, graded=True):
 
     _print_style = 'lex'
 
+    def is_prime_field(self):
+        return False
+
     # Todo: share this with ncsf and over algebras with basis indexed by word-like elements
     def __getitem__(self, c):
         r"""

src/sage/combinat/species/generating_series.py

@@ -142,7 +142,7 @@ def __init__(self, base_ring):
             sage: from sage.combinat.species.generating_series import OrdinaryGeneratingSeriesRing
             sage: OrdinaryGeneratingSeriesRing.options.halting_precision(15)
             sage: R = OrdinaryGeneratingSeriesRing(QQ)
-            sage: TestSuite(R).run()
+            sage: TestSuite(R).run(skip="_test_construction")
 
             sage: OrdinaryGeneratingSeriesRing.options._reset()  # reset options
         """
@@ -269,7 +269,7 @@ def __init__(self, base_ring):
             sage: from sage.combinat.species.generating_series import ExponentialGeneratingSeriesRing
             sage: ExponentialGeneratingSeriesRing.options.halting_precision(15)
             sage: R = ExponentialGeneratingSeriesRing(QQ)
-            sage: TestSuite(R).run()
+            sage: TestSuite(R).run(skip="_test_construction")
 
             sage: ExponentialGeneratingSeriesRing.options._reset()  # reset options
         """

src/sage/combinat/species/species.py

@@ -376,7 +376,7 @@ def structures(self, labels, structure_class=None):
             sage: F.structures([1,2,3]).list()
             Traceback (most recent call last):
             ...
-            NotImplementedError
+            ValueError: Stream is not yet defined
         """
         return StructuresWrapper(self, labels, structure_class)
 
@@ -388,7 +388,7 @@ def isotypes(self, labels, structure_class=None):
             sage: F.isotypes([1,2,3]).list()
             Traceback (most recent call last):
             ...
-            NotImplementedError
+            ValueError: Stream is not yet defined
         """
         return IsotypesWrapper(self, labels, structure_class=structure_class)