[Swig-user] Custom Iterator for Python

[Gregory B. <gre...@gm...>]

Hi,

I am running SWIG 1.3.29 (I can't upgrade because an apparent bug where my
virtual functions in director classes go into infinite recursion loops in
1.3.30+) with Python 2.4.4.  I am trying to wrap a class which provides a
custom iterator to access price elements.  I tried cloning the std_map.i
behavior which I found in the examples/library code, but I'm getting the
following error:

LINUX_GCC_RELEASE/__mylib__.cpp:3528:   instantiated from `static
swig_type_info* swig::traits_info<Type>::type_info() [with Type = MyPrice]'
LINUX_GCC_RELEASE/__mylib__.cpp:3535:   instantiated from `swig_type_info*
swig::type_info() [with Type = MyPrice]'
LINUX_GCC_RELEASE/__mylib__.cpp:3569:   instantiated from `static PyObject*
swig::traits_from_ptr<Type>::from(Type*, int) [with Type = MyPrice]'
LINUX_GCC_RELEASE/__mylib__.cpp:3575:   instantiated from `static PyObject*
swig::traits_from<Type>::from(const Type&) [with Type = MyPrice]'
LINUX_GCC_RELEASE/__mylib__.cpp:3587:   instantiated from `PyObject*
swig::from(const Type&) [with Type = MyPrice]'
LINUX_GCC_RELEASE/__mylib__.cpp:4077:   instantiated from `PyObject*
swig::from_oper<ValueType>::operator()(const ValueType&) const [with
ValueType = const MyPrice]'
LINUX_GCC_RELEASE/__mylib__.cpp:4145:   instantiated from `PyObject*
swig::PySwigIteratorClosed_T<OutIterator, ValueType, FromOper>::value()
const [with OutIterator = MyOrderBook::const_iterator, ValueType = const
MyPrice, FromOper = swig::from_oper<const MyPrice>]'
/tooltree/boost-
1.33.1-sa_2/include/boost-1_33_1/boost/mpl/aux_/has_type.hpp:20:
instantiated from here
LINUX_GCC_RELEASE/__mylib__.cpp:3518: error: 'struct swig::traits<MyPrice>'
   has no member named 'type_name'

My wrapping code is as follows where the MyOrderBook class has two methods
"const_iterator begin()" and "const_iterator end()":

%extend MyOrderBook
{
   %newobject iterator(PyObject **PYTHON_SELF);
   swig::PySwigIterator* iterator(PyObject **PYTHON_SELF)
   {
      return swig::make_output_iterator(self->begin(), self->begin(),
self->end(), *PYTHON_SELF);
   }

   %pythoncode
   {
      def __iter__(self): return self.iterator()
   }
}

Sadly, I can't use a standard library container for wrapping. Does anyone
see anything obvious I'm doing wrong or even better, does anyone have any
custom iterator example code outside of the std_*.i and
pycontainer.swgfiles included in the distribution?  Any help would be
greatly appreciated.

Thanks,
Greg