[pygccxml-development] [FT] recent changes - generated code

[Roman Y. <rom...@gm...>]

Hi. Few comments on generated code:

1. Boost.Python object.hpp defines "len" function.
    This will impove next code:

        if (v.attr("__len__")()!=3)
        {
          PyErr_SetString(PyExc_ValueError, "Invalid sequence size
(expected 3)");
          boost::python::throw_error_already_set();
        }

2. The next pattern is comming all the time:

    if( not condition ){
        set python error
        throw boost::python exception
    }

I know we are talking about code generator, but may be we can introduce few
convinience functions?

namespace pyplusplus{ namespace convinience{
void raise_error( exception, message ){
    PyErr_SetString(exception, message);
    boost::python::throw_error_already_set();
}
} }


3.

py_v = pyresult;
          if (!PySequence_Check(py_v.ptr()))
          {
            PyErr_SetString(PyExc_ValueError, "fixed_output_array:
sequence expected as return value for output array 'v'");
            boost::python::throw_error_already_set();
          }
          // Assert that the sequence has the correct size
          if (PySequence_Length(py_v.ptr())!=3)
          {
            PyErr_SetString(PyExc_ValueError, "fixed_output_array:
sequence with 3 values expected as return value for output array
'v'");
            boost::python::throw_error_already_set();
          }

It is obvious to me that we have to have hear "ensure_sequence" function

template< class ItemType=any >
void ensure_sequence( PyObject* x, Py_ssize_t expected_size=-1 ) {
    if not sequence: raise
    if does not have desired length raise
    if items in sequence are not from desired type raise
}

Something like this.

I would like to see these changes. The generated code should not be
too different
from the one, that human would write. I don't write code like this.

P.S. Matthias I hope you don't mind I do the review, right?
-- 
Roman Yakovenko
C++ Python language binding
http://www.language-binding.net/