Ticket #13447: trac_13447-attempted_improvement.patch

sage/libs/singular/function.pxd

@@ -57 +57 @@
     cdef to_python(self, leftv* to_convert)
 
 cdef class BaseCallHandler:
-    cdef leftv* handle_call(self, Converter argument_list, singular_ring *_ring=?)
+    cdef leftv* handle_call(self, Converter argument_list, singular_ring *_ring=?) except NULL
     cdef bint free_res(self)
 
 cdef class LibraryCallHandler(BaseCallHandler):

sage/libs/singular/function.pyx

@@ -1011 +1011 @@
     A call handler is an abstraction which hides the details of the
     implementation differences between kernel and library functions.
     """
-    cdef leftv* handle_call(self, Converter argument_list, ring *_ring=NULL):
+    cdef leftv* handle_call(self, Converter argument_list, ring *_ring=NULL) except NULL:
         """
         Actual function call.
         """
-        return NULL
+        #return NULL
+        raise NotImplementedError
 
     cdef bint free_res(self):
         """
@@ -1045 +1046 @@
         """
         super(LibraryCallHandler, self).__init__()
 
-    cdef leftv* handle_call(self, Converter argument_list, ring *_ring=NULL):
+    cdef leftv* handle_call(self, Converter argument_list, ring *_ring=NULL) except NULL:
         if _ring != currRing: rChangeCurrRing(_ring)
-        return iiMake_proc(self.proc_idhdl, NULL, argument_list.args)
+        cdef leftv* res = iiMake_proc(self.proc_idhdl, NULL, argument_list.args)
+        if res == NULL:
+            raise RuntimeError, "Error during Singular library function call '%s'"%self._name
+        return res
         
     cdef bint free_res(self):
         """
@@ -1080 +1084 @@
         self.cmd_n = cmd_n
         self.arity = arity
 
-    cdef leftv* handle_call(self, Converter argument_list, ring *_ring=NULL):
+    cdef leftv* handle_call(self, Converter argument_list, ring *_ring=NULL) except NULL:
         cdef leftv * res
         res = <leftv*> omAllocBin(sleftv_bin)
         res.Init()
         cdef leftv *arg1
         cdef leftv *arg2
         cdef leftv *arg3
-
         cdef int number_of_arguments = len(argument_list)
 
         # Handle functions with an arbitrary number of arguments, sent
@@ -1095 +1098 @@
         if self.arity in [CMD_M, ROOT_DECL_LIST, RING_DECL_LIST]:
             if _ring != currRing: rChangeCurrRing(_ring)
             iiExprArithM(res, argument_list.args, self.cmd_n)
+            if res == NULL:
+                raise RuntimeError, "Error during Singular kernel function '%s'"%self._name
             return res
 
         if number_of_arguments == 1:
@@ -1410 +1415 @@
     global myynest
     global error_messages
 
-
     cdef ring *si_ring
     if PY_TYPE_CHECK(R, MPolynomialRing_libsingular):
         si_ring = (<MPolynomialRing_libsingular>R)._ring
@@ -1452 +1456 @@
         error_messages.pop()
 
     # In the Singular interpreter, we must ensure that currRing->ref > 0.
-    currRing.ref += 1
+    si_ring.ref += 1
     try:
         with opt_ctx: # we are preserving the global options state here
             if signal_handler:
@@ -1482 +1486 @@
 
         return res
     finally:
-        currRing.ref -= 1
+        si_ring.ref -= 1
         
 cdef class SingularLibraryFunction(SingularFunction):
     """
@@ -1509 +1513 @@
             [y - 1, x + 1]
         """
         super(SingularLibraryFunction,self).__init__(name)
-        # the following will yield a NameError, if the function
-        # is not defined in a previously loaded library
-        self.call_handler = self.get_call_handler()
+        if ggetid(name)==NULL:
+            raise NameError("Function '%s' is not defined."%name)
 
     cdef BaseCallHandler get_call_handler(self):
         cdef idhdl* singular_idhdl = ggetid(self._name)