If you declare, for example, _operands to be a list, and cdef _operands(self) to be a function in the same class, mysterious errors can be produced such as:
Traceback (most recent call last):
File "/home/gfurnish/sage-3.0.6/local/bin/cython", line 8, in <module>
main(command_line = 1)
File "/home/gfurnish/sage-3.0.6/local/lib/python2.5/site-packages/Cython/Compiler/Main.py", line 527, in main
result = compile(sources, options)
File "/home/gfurnish/sage-3.0.6/local/lib/python2.5/site-packages/Cython/Compiler/Main.py", line 505, in compile
return compile_multiple(source, options)
File "/home/gfurnish/sage-3.0.6/local/lib/python2.5/site-packages/Cython/Compiler/Main.py", line 472, in compile_multiple
result = context.compile(source, options)
File "/home/gfurnish/sage-3.0.6/local/lib/python2.5/site-packages/Cython/Compiler/Main.py", line 327, in compile
tree.process_implementation(scope, options, result)
File "/home/gfurnish/sage-3.0.6/local/lib/python2.5/site-packages/Cython/Compiler/ModuleNode.py", line 59, in process_implementation
self.generate_c_code(env, options, result)
File "/home/gfurnish/sage-3.0.6/local/lib/python2.5/site-packages/Cython/Compiler/ModuleNode.py", line 243, in generate_c_code
self.body.generate_function_definitions(env, code, options.transforms)
File "/home/gfurnish/sage-3.0.6/local/lib/python2.5/site-packages/Cython/Compiler/Nodes.py", line 252, in generate_function_definitions
stat.generate_function_definitions(env, code, transforms)
File "/home/gfurnish/sage-3.0.6/local/lib/python2.5/site-packages/Cython/Compiler/Nodes.py", line 2051, in generate_function_definitions
self.entry.type.scope, code, transforms)
File "/home/gfurnish/sage-3.0.6/local/lib/python2.5/site-packages/Cython/Compiler/Nodes.py", line 252, in generate_function_definitions
stat.generate_function_definitions(env, code, transforms)
File "/home/gfurnish/sage-3.0.6/local/lib/python2.5/site-packages/Cython/Compiler/Nodes.py", line 892, in generate_function_definitions
exc_check = self.caller_will_check_exceptions()
File "/home/gfurnish/sage-3.0.6/local/lib/python2.5/site-packages/Cython/Compiler/Nodes.py", line 1162, in caller_will_check_exceptions
return self.entry.type.exception_check
AttributeError: BuiltinObjectType instance has no attribute 'exception_check'
