[C++-sig] Re: Refactoring, Compilation Speed, Pyste, Lua/Ruby/JavaScript...

[Brett Calcott]

> >
> > As somebody who has tried to go through the library, this bit is the
> > part I'd really like to understand. I'm sure the reorganisation
> > would help, but I'd really love to read a short doc on how this
> > actually all hangs together. The registry, how the templates
> > automates the construction of the PyObject and Type, how conversions
> > are looked up (what's that graph stuff in there?).
>
> The graph stuff is not in this layer, it's in the core.  It
> implements something like this:
>
>     dst_ptr = dynamic_cast(src_void_ptr, src_type_id, dst_type_id)
>

Ok. So I think I need to know about the core as well then.


> >
> > I think I could use the library better and assist more in extending it
if I
> > could put all the bits together in my head.(I have in mind something
like
> > the big text file that Joel wrote for Phoenix.)
> >
> > Just putting in a bid for your time Dave...
>
> Well, I'd be happy to collaborate with you on an implementation
> document.  It's not something I can afford to do by myself, in part
> because I don't know what questions to answer.  If you would agree to
> have a conversation with me about it here, and from that create a
> RestructuredText document which we'll include in the CVS, I'd be more
> than happy to type out details at length.  I think you might have to
> dig into the code a little, too.  Deal?
>

Deal. It be a bit slow at first as I am relocating to another country in the
next 10 days (NZ -> Aussie), so my internet connection will be sporadic, and
I'll be busy finding a new home and settling in.

I'd like to approach it as though we are trying to write a simplified
version of boost.python, ignoring compiler workarounds, and not using the
preproc. We'll show a coded python C extension, an equivalent in
boost.python syntax, then go through the structures needed for the
boost.python code to generate the equivalently operating C extension code
that we initially showed.

We could work through examples like the ones on this page :

http://starship.python.net/crew/arcege/extwriting/pyext.html


ie.

python extension:
=================
PyObject *python_add(self, args)....
...
...
..


PyMethodDef methods[] = {
{
    "add", MyCommand, METH_VARARGS},
    {NULL, NULL},
};


void initexample()
{
    (void)Py_InitModule("add", methods);
}


equivalent in boost
==================
...
    def("add", python_add);


Explain how the boost example generated equivalent code to above using very
cut-down techniques that capture the 'essence' of the boost.python
implementation, but not the detail.
=================
1. The module def
2. how is the methods array created (or simulated)
3. How does argument parsing happen..
...etc..


Does this make sense?
Comments (from anyone)?

Cheers,
Brett