Add some excepts (#1)

For C-return-type functions that raise exceptions (and their heirs).

src/sage/matroids/basis_exchange_matroid.pxd

@@ -46,7 +46,7 @@ cdef class BasisExchangeMatroid(Matroid):
     cpdef _move_current_basis(self, X, Y)
 
     cpdef frozenset _max_independent(self, frozenset F)
-    cpdef int _rank(self, frozenset F) noexcept
+    cpdef int _rank(self, frozenset F) except -1
     cpdef frozenset _circuit(self, frozenset F)
     cpdef frozenset _fundamental_circuit(self, frozenset B, e)
     cpdef frozenset _closure(self, frozenset F)

src/sage/matroids/basis_exchange_matroid.pyx

@@ -652,7 +652,7 @@ cdef class BasisExchangeMatroid(Matroid):
         self.__max_independent(self._output, self._input)
         return self.__unpack(self._output)
 
-    cpdef int _rank(self, frozenset F) noexcept:
+    cpdef int _rank(self, frozenset F) except -1:
         """
         Compute the rank of a subset of the groundset.
 

src/sage/matroids/circuit_closures_matroid.pxd

@@ -5,7 +5,7 @@ cdef class CircuitClosuresMatroid(Matroid):
     cdef dict _circuit_closures  # _CC
     cdef int _matroid_rank  # _R
     cpdef frozenset groundset(self)
-    cpdef int _rank(self, frozenset X) noexcept
+    cpdef int _rank(self, frozenset X) except -1
     cpdef full_rank(self)
     cpdef bint _is_independent(self, frozenset F) noexcept
     cpdef frozenset _max_independent(self, frozenset F)

src/sage/matroids/circuit_closures_matroid.pyx

@@ -179,7 +179,7 @@ cdef class CircuitClosuresMatroid(Matroid):
         """
         return frozenset(self._groundset)
 
-    cpdef int _rank(self, frozenset X) noexcept:
+    cpdef int _rank(self, frozenset X) except -1:
         """
         Return the rank of a set ``X``.
 

src/sage/matroids/circuits_matroid.pxd

@@ -9,7 +9,7 @@ cdef class CircuitsMatroid(Matroid):
     cdef list _sorted_C_lens
     cdef bint _nsc_defined
     cpdef frozenset groundset(self)
-    cpdef int _rank(self, frozenset X) noexcept
+    cpdef int _rank(self, frozenset X) except -1
     cpdef full_rank(self)
     cpdef bint _is_independent(self, frozenset X) noexcept
     cpdef frozenset _max_independent(self, frozenset X)

src/sage/matroids/circuits_matroid.pyx

@@ -100,7 +100,7 @@ cdef class CircuitsMatroid(Matroid):
         """
         return self._groundset
 
-    cpdef int _rank(self, frozenset X) noexcept:
+    cpdef int _rank(self, frozenset X) except -1:
         """
         Return the rank of a set ``X``.
 

src/sage/matroids/flats_matroid.pxd

@@ -8,7 +8,7 @@ cdef class FlatsMatroid(Matroid):
     cdef object _L  # lattice of flats
     cpdef frozenset groundset(self)
 
-    cpdef int _rank(self, frozenset X) noexcept
+    cpdef int _rank(self, frozenset X) except -1
     cpdef frozenset _closure(self, frozenset X)
     cpdef bint _is_closed(self, frozenset X) noexcept
 

src/sage/matroids/flats_matroid.pyx

@@ -114,7 +114,7 @@ cdef class FlatsMatroid(Matroid):
         """
         return self._groundset
 
-    cpdef int _rank(self, frozenset X) noexcept:
+    cpdef int _rank(self, frozenset X) except -1:
         """
         Return the rank of a set ``X``.
 

src/sage/matroids/graphic_matroid.pxd

@@ -7,7 +7,7 @@ cdef class GraphicMatroid(Matroid):
     cdef dict _vertex_map
     cdef dict _groundset_edge_map
     cpdef frozenset groundset(self)
-    cpdef int _rank(self, frozenset X) noexcept
+    cpdef int _rank(self, frozenset X) except -1
     cpdef _vertex_stars(self)
     cpdef _minor(self, contractions, deletions)
     cpdef _has_minor(self, N, bint certificate=*)

src/sage/matroids/graphic_matroid.pyx

@@ -238,7 +238,7 @@ cdef class GraphicMatroid(Matroid):
         """
         return self._groundset
 
-    cpdef int _rank(self, frozenset X) noexcept:
+    cpdef int _rank(self, frozenset X) except -1:
         """
         Return the rank of a set ``X``.
 

src/sage/matroids/matroid.pxd

@@ -9,7 +9,7 @@ cdef class Matroid(SageObject):
 
     # virtual methods
     cpdef frozenset groundset(self)
-    cpdef int _rank(self, frozenset X) noexcept
+    cpdef int _rank(self, frozenset X) except -1
 
     # internal methods, assuming verified input
     cpdef frozenset _max_independent(self, frozenset X)

src/sage/matroids/matroid.pyx

@@ -492,7 +492,7 @@ cdef class Matroid(SageObject):
         """
         raise NotImplementedError("subclasses need to implement this")
 
-    cpdef int _rank(self, frozenset X) noexcept:
+    cpdef int _rank(self, frozenset X) except -1:
         r"""
         Return the rank of a set ``X``.
 
@@ -513,8 +513,9 @@ cdef class Matroid(SageObject):
 
             sage: M = sage.matroids.matroid.Matroid()
             sage: M._rank(frozenset([0, 1, 2]))
-            NotImplementedError: subclasses need to implement this
+            Traceback (most recent call last):
             ...
+            NotImplementedError: subclasses need to implement this
         """
         raise NotImplementedError("subclasses need to implement this")
 
@@ -2338,7 +2339,7 @@ cdef class Matroid(SageObject):
         TESTS::
 
             sage: def r(X):
-            ....:     return -1
+            ....:     return -2
             sage: M = Matroid(groundset=[0,1,2], rank_function=r)
             sage: M.is_valid()
             False

src/sage/matroids/union_matroid.pxd

@@ -5,16 +5,16 @@ cdef class MatroidUnion(Matroid):
     cdef list matroids
     cdef frozenset _groundset
     cpdef frozenset groundset(self)
-    cpdef int _rank(self, frozenset X) noexcept
+    cpdef int _rank(self, frozenset X) except -1
 
 cdef class MatroidSum(Matroid):
     cdef list summands
     cdef frozenset _groundset
     cpdef frozenset groundset(self)
-    cpdef int _rank(self, frozenset X) noexcept
+    cpdef int _rank(self, frozenset X) except -1
 
 cdef class PartitionMatroid(Matroid):
     cdef dict p
     cdef frozenset _groundset
     cpdef frozenset groundset(self)
-    cpdef int _rank(self, frozenset X) noexcept
+    cpdef int _rank(self, frozenset X) except -1

src/sage/matroids/union_matroid.pyx

@@ -66,7 +66,7 @@ cdef class MatroidUnion(Matroid):
         """
         return self._groundset
 
-    cpdef int _rank(self, frozenset X) noexcept:
+    cpdef int _rank(self, frozenset X) except -1:
         r"""
         Return the rank of a set ``X``.
 
@@ -195,7 +195,7 @@ cdef class MatroidSum(Matroid):
         """
         return self._groundset
 
-    cpdef int _rank(self, frozenset X) noexcept:
+    cpdef int _rank(self, frozenset X) except -1:
         r"""
         Return the rank of a set ``X``.
 
@@ -290,7 +290,7 @@ cdef class PartitionMatroid(Matroid):
         """
         return self._groundset
 
-    cpdef int _rank(self, frozenset X) noexcept:
+    cpdef int _rank(self, frozenset X) except -1:
         r"""
         Return the rank of a set ``X``.
 

src/sage/sets/disjoint_set.pxd

@@ -19,8 +19,8 @@ cdef class DisjointSet_class(SageObject):
     cpdef number_of_subsets(self)
 
 cdef class DisjointSet_of_integers(DisjointSet_class):
-    cpdef int find(self, int i) noexcept
-    cpdef void union(self, int i, int j) noexcept
+    cpdef int find(self, int i) except -1
+    cpdef void union(self, int i, int j) except *
     cpdef root_to_elements_dict(self)
     cpdef element_to_root_dict(self)
     cpdef to_digraph(self)

src/sage/sets/disjoint_set.pyx

@@ -448,7 +448,7 @@ cdef class DisjointSet_of_integers(DisjointSet_class):
         for i, parent in enumerate(l):
             self.union(parent, i)
 
-    cpdef int find(self, int i) noexcept:
+    cpdef int find(self, int i) except -1:
         r"""
         Return the representative of the set that ``i`` currently belongs to.
 
@@ -479,8 +479,9 @@ cdef class DisjointSet_of_integers(DisjointSet_class):
             sage: [e.find(i) for i in range(5)]
             [0, 1, 1, 1, 1]
             sage: e.find(2**10)
-            ValueError: i must be between 0 and 4 (1024 given)
+            Traceback (most recent call last):
             ...
+            ValueError: i must be between 0 and 4 (1024 given)
 
         .. NOTE::
 
@@ -492,7 +493,7 @@ cdef class DisjointSet_of_integers(DisjointSet_class):
             raise ValueError('i must be between 0 and %s (%s given)' % (card - 1, i))
         return OP_find(self._nodes, i)
 
-    cpdef void union(self, int i, int j) noexcept:
+    cpdef void union(self, int i, int j) except *:
         r"""
         Combine the set of ``i`` and the set of ``j`` into one.
 
@@ -520,8 +521,9 @@ cdef class DisjointSet_of_integers(DisjointSet_class):
             sage: d
             {{0, 1, 2, 4}, {3}}
             sage: d.union(1, 5)
-            ValueError: j must be between 0 and 4 (5 given)
+            Traceback (most recent call last):
             ...
+            ValueError: j must be between 0 and 4 (5 given)
 
         .. NOTE::